Physica status solidi / A.: Volume 106, Number 1 March 16 [Reprint 2021 ed.] 9783112480823, 9783112480816

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physica status solidi (a) applied research

Volume 106 AKADEMIE-VERLAG ISSN 0031-8965

Number 1

March 1988

BERLIN

phys. stat. sol. (a), Berlin 106 (1988) 1, 1 - 3«>4, Kl

Kt!6, At—A8

International Classification System for Physics*) 60. Condensed matter: structure, mechanical and thermal properties 61. Structure of liquids and solids; crystallography (see also 68.20. Solid surface structure, 71. Electron states) 62. Mechanical and acoustical properties of condensed matter (see also 61.70. Defects in crystals, 68.30. Surfaces and interfaces) 63. Lattice dynamics and crystal statistics (see also 65. Thermal properties, 66.70. Thermal conduction, 68.30. Dynamics of surface and interface vibrations, 78.30. Infrared and Raman spectra) 64. Equations of state, phase equilibria, and phase transitions 65. Thermal properties of condensed matter (see also 63. Lattice dynamics; for thermodynamic properties of quantum fluids, see 67.40; for thermal properties of solid helium, see 67.80) 66. Transport properties of condensed matter (nonelectronic) 67. Quantum fluids and solids; liquid and solid helium 68. Surfaces and interfaces; thin films and whiskers (for impact phenomena, see 79; for crystal growth, see 61.50) 70. Condensed matter: electronic structure; electrical, magnetic, and optical properties 71. Electronic states (see also 63. Lattice dynamics, 73. Electronic structure and electrical properties of surfaces, interfaces, and thin films) 72. Electronic transport in condensed matter (for surfaces, interfaces, and thin films, see 73) 73. Electronic and electrical properties of surfaces, interfaces, and thin films 74. Superconductivity 75. Magnetic properties and materials 76. Magnetic resonances and relaxation in condensed matter; Mossbauer effect 77. Dielectric properties and materials (for conductivity phenomena, see 72.20 and 72.80) 78. Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiatipn (for phonon spectra, see 63) 79. Electron and ion emission by liquids and solids; impact phenomena 85. Devices**)

*) Excerpt; reproduced with permission of International Council for Scientific and Technical Information (ICSTI). **) Outside the ICSTI Classification for Physics.

(The Substance Classification is given on cover three)

physica status solidi (a) applied research

B o a r d of E d i t o r s S. A M E L I N C K X , Mol-Donk, J. A U T H , Berlin, H. B E T H G E , Halle, K. W. B Ö E R , Newark, E. G U T S C H E , Berlin, P. H A A S E N , Göttingen, G. M. H A T O Y A M A , Tokyo, B. T. K O L O M I E T S , Leningrad, W. J . M E R Z , Zürich, G. O. M Ü L L E R , Berlin, A. S E E G E R , Stuttgart, S. S H I O N O Y A , Tokyo, C. M. V A N V L I E T , Montreal, E. P. W O H L F A R T H , London Editor-in-Chief E. G U T S C H E Advisory Board L. N. A L E K S A N D R O V , Novosibirsk, W. A N D R Ä , Jena, H. B Ä S S L E R , Marburg, E. B A U E R , Clausthal-Zellerfeld, G. C H I A R O T T I , Rom, H. C U R I E N , Paris, R. G R I G O R O V I C I , Bucharest, J . H E Y D E N R E I C H , Halle, E. B. H U M P H R E Y , Pasadena, A. A. K A M I N S K I I , Moskva, E. K L I E R , Praha, Y. N A K A M U R A , Kyoto, J . N I H O U L , Mol, T. N. R H O D I N , Ithaca, New York, R. S I Z M A N N , München, J. S T U K E , Marburg, J . T. W A L L M A R K , Göteborg

Volume 106 • Number 1 • Pages 1 to 304, K l to K116, and Al to A8 March 16, 1988

AKADEMIE-VERLAG

BERLIN

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INTERNATIONAL CONFERENCE ON OPTICAL NONLINEARITY AND BISTABILITY OF SEMICONDUCTORS

August 22 to 25, 1988, Berlin, GDR A satellite meeting to the 19th International Conference on the Physics of Semiconductors,Warsaw, Poland, August 15 to 18, 1988 organized by Humboldt-Universität zu Berlin, Sektion Physik

International Organizing and Program Committee F. Henneberger (Chairman), Berlin H. J . Eichler, Berlin (West) J . B. Grun, Strasbourg I. Janossy, Budapest F. V. Karpushko, Minsk C. Klingshirn, Kaiserslautern

N. Nagasawa, Tokyo N. Peyghambarian, Tucson S. Schmitt-Rink, Murray-Hill S. D. Smith, Edinburgh R. Zimmermann, Berlin

National Organizing Committee (Berlin) R. Enderlein (Chairman) I. Rückmann (Secretary) J . Puls (Proceedings) H. Rossmann (Local Arrangements) Correspondence

:

F. Henneberger, Conference Chairman Humboldt-University, Berlin Department of Physics — Semiconductor Optics Invalidenstr. 110 1040 Berlin, GDR Telex 114759 huphy dd, Phone 2803200 Scope of

Conference

The conference is intended to provide an international forum for the exchange of information on all experimental and theoretical aspects of nonlinear optical processes and bistability of semiconductors and semiconductor structures.

Topics to be Emphasized — Fundamental Aspects of Light-Matter Interaction in Semiconductors — Physical Mechanisms of Large Optical Nonlinearities — New Schemes for Optical Bistability — Ultrashort Pulse Phenomena — Laser-Induced Gratings and Phase Conjugation in Semiconductors — Physics of Nonlinear Electro-Optical Switches — Advances in Nonlinear Optical Devices and Circuits Invited Talks The following speakers have agreed to present keynote talks: H. J . Eichler (Berlin (West))

Optical Nonlinearity and Bistability of Silicon

A . I. Ekimov (Leningrad)

Nonlinear Optics of Semiconductor-Doped Glasses

B . I. Greene and J. Orenstein (Murray Hill)

Nonlinear Optical Properties of One-Dimensional Excitons in Polydiacetylen

B . Hönerlage, R . L e v y , and J. B . Grun (Strasbourg)

Time-Resolved Light-Induced Grating Spectroscopy in Semiconductors

I. Janossy (Budapest)

Nonlinear Optical Effects in Amorphous Semiconductors

C. Klingshirn and H. E. Svoboda (Kaiserslautern)

Nonlinear Optical Properties of the System Cd-jSex-z

S. W . Kóch (Tucson)

Theory of Transmission Oscillations and Optical Stark Effect in Semiconductors

T. Kobayashi (Tokyo)

Investigation of Ultrashort Phenomena in Semiconductors

N. Nagasawa (Tokyo)

Optical Nonlinearity Due to Exciton System in CuCI

N. Peyghambarian (Tucson)

Measurements of Ultrafast Optical Nonlinearities in Semiconductors

C. R . Pidgeon, H. A. MacKenzie, A. C. Walker, and S. D. Smith (Edinburgh)

Dynamical Optical Nonlinearity and Bistability of NarrowGap Semiconductors

B . S. R y v k i n (Leningrad)

Semiconductor Cell with n-Type Photocurrent-Voltage Characteristic: A New Class of Nonlinear Optical Elements

S. Schmitt-Rink (Murray Hill)

Coherent Nonlinear Optical Processes in Semiconductors: Physics and Application

G. V. Sinitsyn and P. V . Karpushko Digital Circuits for All-Optical Computing Based on ThinFilm Semiconductor Interferometers (Minsk) A . Smirl, J. Dubard, G. C. Valley, and T. F . Bogges (Denton)

Picosecond Optical Nonlinearities, Photorefractive Switching, and Beam Amplification in Semiconductors

J. Tomlinson (Bellcore)

Nonlinear Phenomena in Single Mode Optical Fibres

R . Zimmermann (Berlin)

Resonant and Off-Resonant Light-Matter Interaction in Semiconductors: Kinetics and Transients

All papers — invited and contributed — presented at the conference will be published in a special issue of "physica status solidi (b) — basic research"

phys. stat. sol. (a) 105 (1988)

Author Index B . S. ACHARYA P . K . ACHARYA B . S . V . S . R . ACHARYULU T . AKACHI I . A . AKSENOV K . A . AL-SALEH M . ALBANI K . S . ALEKSANDROV 1. P . ALEKSANDROVA M . M . ALEKSANDROVA J . P . ALLEMAND W . ANDRÀ V . N . ANISIMOVA S . ANN AM ALAI A . APOSTOLOV . W . APPEL E . T . ARAKAWA 0 . ARÉS MUZIO 1. M . ASKEROV G . K . ASLANOV A . G . BALOGH U . BARKOW C. BARTHOU J . BASZYNSKI T . BAUMBACH G . BEISTER P . BENALLOUL J . BENOIT H . VON BERLEPSCH A . VAN DEN B E U K E L A . P . BEZIRGANYAN P . A . BEZIRGANYAN K . BIALAS-BORGIEL S . K . BISWAS V . D . BLANK C . DE BLASI A . C. BÓDI G . BRAUER T . BREMER H . H . BRONGERSMA V . N . BRUDNYI H . - G . BRUHL Y U . A . BURENKOV M . CATALONO P . CAVALIERE Z . CELII&SKI G . CHABRIER ST. CHARALAMBOUS S . CHAUDHURI M . CHAVEZ GUANGHUA CHEN T . CHOT A . CHOUDHURY

455 171 303 411 K97 177 661 441 145 K29 427 589 139 171 K145 589, K 6 7 617 243, 285 K151 K151

K57,

K7 627 637 501 197 K45 637 637 485 235 345 345 567 467 K29 101 573 K7 K17 493 K141 197 K103 101 101 567 617 K175 467 411 K41 K121 467

YUAN-CHAO CHU A . CÍZEK L . M . CLAREBROUGII N . CLARK M . CLAUSNITZER L L . CLOSAS A . E . CÜRZON Z . CZAPLA K . CZUPRYÑSKI

K1 357 131, 3 6 5 K125 53 541 335 K33 K107

H . J . VAN DAAL R . D4BROWSKI W . DJ^BROWSKI A. DE I . Y A . DEKHTYAR I . DÉZSI S . DÍAZ CASTAÑÓN L . DOZSA P . DUHAJ S . V . DYACIIENKO

493 K107 511 297 357 219 243 521 . 319 87

A . I . EATAH K . EFTAXIAS V . M . EGOROV E . E L FARAMAWY A . P . ELISEEV H . ENGELMANN R . ESCUDERO S . A . ESHRAGHI E . I . ESTRIN A . EXTREMERA

231 K87 K93 231 K169 219 411 563 K29 281

J . M . B . FERNANDES DINIZ J . FERNÁNDEZ RUBIO J . G . FLEMING I . N . FLEROV H . - J . FÓCKEL A . FORKL R . FORNARI C. T . FORWOOD F . FOUQUET F . C. FRANK N . GANESAN S . GARCÍA GARCÍA W . GATZWEILER TINGSUI G E A . L . GENTILE A . GEOFFROY A . A . GHANI R . GILDE T H . GOLDBERG A . E . GOLOBOKOV A . V . GOLUBKOV U . GONSER J . P . GOUDONNET J . GRIESCHE

123 541 77 441 KLLL 597 521 131, 365 427 K21 461 243 219 447 563 637 231 493 KLLL K29 K93, K103 219 617 189

Author Index

672 R . GRONSKY B . DE GUILLEBON S . N . GUPTA I . GY(JRÖ V . HADJICONTIS J . HARTWIG M . A . HASSAN . YIZHEN HE M . HEIDER W . HEILAND W . HERTLE A . A . HIRSCH H . - R . HÖCHE C. A . HOGARTH V . HOLY E . HUIZER

207 427 275 K129

• .

.

K87 61 609 325 661 K17 K7 249 53 609 61 235

A . IBARRA I . ILEO T . INAGAKI G. IRMER

601 573 617 549

J . JABLONSKI I . J . JABR B . JACOBS H . U . JÄGER M . JIMENEZ DE CASTRO

113 177 661 387 601

S . KADECKOVÄ I . V . KAMENSKAYA A . A . KAMINSKII H . KAMLEH N . KAPOOR L . A . KAZAKEVICII T. S. KE F . R . KESSLER M . N . KHAN S . KIANIAN H . S . KIM S . KISHIDA G. KITIS R . KITTNER A . KLEKAMP D . KÖHLER E . KOKMEIJER I . T . KOKOV Y U . S . KONYAEV G. KOSCHEK B . KÖSCIELNIAK-MUCHA E . KRÄTZIG U . KREISSIG H . KRONMÜLLER A . I . KRUGLIK E . KUBALEK J . KUBENA K . KUCHARSKI A . KUCZOWSKI

K37 K141 K155 661 403 97 447 627 609 563 45 K165 K175 61 K17 377 235 441 K29 377 K135 K17 387 597 441 377 61 113 K61

V . S . KISHAN KUMAR K . KURBANOV V . I . KUZNETSOV

303 KL55 97

H . K . LACHOWICZ M . LAZARIDOU G. F . LEAL FERREIRA A . B . LEBEDEV F . LECCABUE V . LERCHE LE THANH BINH C . A . LONDOS T . LUCINSKI P . F . LUGAKOV

597 K13 531 K103 285 61 K51 K87 501 97

E . G. MADATOVA J . MAEGE L . A . MAKOVETSKAYA MING MAO M . J . MARCINKOWSKI T . MASSALHA G. MATERLIK A . MATSUOKA K . MATSUURA A . 0 . MEKIIRABOV S . V . MELNIKOVA J . D . MEYER M . MIKHOV L . Q. MINII T . MIYAZAKI S . MOHAN F . MONZER N . MOSER Y U . N . MOSKVICH J . MRÖZ K . R . MURALI V . R . K . MURTHY Y . V . G. S . MURTI

357 K45 K97 325 K25 249 53 K165 K165 K151 441 177 K145 K121 263 K181 661 597 145 K33 477 K71 397

L . E . NAGLI Y . NAKAMURA S . M . NAKHMETOV Y . D . NATSIK B . B . NAYAK J . NIEBER R . NIES A . N . NIGAM S . P . NIKANOROV

87 291 K151 K37 455 53 627 403 K103

T. O. A. T. B. K.

153 531 K135 K93 563 K155

OHGAKU N . OLIVEIRA, J R OPANOWICZ S . ORLOVA OSTROM L . OVANESYAN

P . P . PAL-VAL R . V . PARFENEV

K37 K129

Author Index

673

S. PATU J . PEREZ V . V . PESCHEV P . D . PESTER A . GR. PETROSYAN S. PFEFFER U . PIETSCH M. PINNOW P . V . PIROGOV B . PÖDÖR K . PONNURAJU GT. P . POPELN YUK V . V . POPOV J . PRZEDMOJSKI B . PURA H . PYKACZ

419 427 K57 649 K155 K115 197 485 87 K129 161 K97 K129 K107 K107 K33

E . RAHIMZADEH K . RAJ ANNA O. S. RAJORA A . E . RAKHSHANI K.V.RAO G. RICHTER D . RÍOS-JARA A . RIZZO L . RODRÍGUEZ P . ROYER 0 . V . ROZANOV

K1 K181 335 183 297 K45 411 101 411 617 145

M. SALAGRAM N . S. SALEII E . G. SAMOILOVA J . L . SÁNCHEZ LLAMAZARES S. S. SASTRY P . SATO G. SATYANANDAM D . SCHALCH A . SCHARMANN M. SCHELUDKO D . SCHIKORA B . SCHUBERT M. SEGNINI S . SEN C. A . C. SEQUEIRA V . M. SERGEEVA S . S. SHEININ I . P . SHILOVICH W . SIEGEL A . SIEMKO S. K . SINGH V . SIVARAMAKRISHNAN W . SKORUPA D . SKRZYPEK V . SKUMRIEV B . I . SMIRNOV 1. A . SMIRNOV M. SOB

K161 177 K169 . . . . 243, 285 K71 263 K71 K81 K81 K145 189 K115 K125 171 123 K93 45 K97 549 597 455 461 387 567 K145 K93 K93, K103 357

E . SOBESLAVSKY J . SOBHANADRI J . SOSNOWSKI 0 . M. STAFSUDD R . STEGMANN D . A . STEVENSON A . SUBRAHMANYAM A . A . SUKHOVSKII K . SUMIYAMA GUOSHENG SUN C. S . SUNANDANA M. SUNDARAM P . SVEC B . G. TAGIEV M. TAKAHASHI N . TAKEUCHI P . TCHOLAKOV H . TERAUCHI B . J . THIJSSE G . THOMAS T . TSANG R . TSUMURA 1. TSURUMI . N . UNZNER D . M. VANDERWALKEP. J . VARGHESE C. VAROTSOS A . D . VASILEV P . R . VA Y A H . C. VERMA C. VIJAYAN R . VILA

387 161 555 563 661 77 K71 145 291 K41 11 477 . 319 K151 263 153 K145 197 235 207 K1 411 K165 627 K77 183 K13 441 161, 477 275 397 601

LITIAN WANG Z.G.WANG K . WENTOWSKA T . WILSON J . WOJCIECHOWSKI R . WOLFRAT K . WOLLSCHLAGER

447 419 K107 649 113 K81 387

M. H . X U N . N . XUAN

419 K121

E . D . YAKUSHKIN L. YIN A . M. YURKIN

139 K1 K169

H . W . ZANDBERGEN K . 2ÙÂNSKY A . Y U . ZERR FANGQING ZHANG YAN-ZHONG ZHANG T . B . ZHUKOVA

207 K51 K29 K41 579 K103

phys. stat. sol. (a) 106, No. 1 (1988)

Contents Review Article A Review Article for Volume 106 will appear in No. 2 of this Volume.

Original Papers and Short Notes Structure;

crystallography

G . PASTOR, P . T E J E D O R , I . J I M É N E Z , E . DOMÍNGUEZ, M . TORRES, a n d J . V . GARCÍA-RAMOS

Low Pressure Chemical Vapour Deposition Amorphous Silicon Behaviour under Annealing

11

M . POLOAROVÁ, K . GODWOD, J . B ^ K - M I S I U K , S . KADECKOVA, a n d J . BRÁDLER

I . R. E N T I N

V.

G. K O H N

Lattice Parameters of Fe-Si Alloy Single Crystals

17

Dynamical and Kinematical X-Ray Diffraction in Crystals Strongly Disturbed by Ultrasonic Vibrations

25

X-Ray Standing Waves under the Conditions of Multiple Diffraction .

.

31

X-Ray Interferometric Investigations of Structural Distortions in Semiconductor Crystals Caused by Constant Electric and Magnetic Fields. . .

41

E . Z . A R S H A K Y A N , A . O . A B O Y A N , a n d P . A . BEZIRGANYAN

K . Z . BOTROS, S . M . S A L E H , A . H . G . E L - D H A H E R , a n d S . H A J A I G

On the Visibility of Edge Fringes in Strong Beam Images of Intiinsic and Extrinsic Stacking Faults in F.C.C. Structures

Defects; nonelectronic

49

transport

R . K L A B E S , A . THOMAS, G . RLTJGE, W . B E Y E R , R . GRÓTZSCHEL, a n d P . SÜPTITZ

Ion-Beam Induced Silver Doping in the Ag2Se/GeSe2-Resist System . . .

57

S . D H A N F S K O D I a n d N . HARIHARAN

Radiation Damage of Bisglycine Cadmium Chloride Single Crystals. An E P R Study

67

C . ASCHERON, H . A . K L O S E , W . F R E N T R U P , a n d M . GRIEPENTKOG

Gettering of Copper in Proton- and Helium-Bombarded Buried Regions of Gallium Phosphide l*

73

4

Contents

G . D L U B E K , C . ASCHERON, R . K R A U S E , H . E R H A R D , a n d D . KLIMM

Positron Study of Vacancy Defects in Proton and Neutron Irradiated GaP, InP, and Si

81

R . SOMMERFELDT, L . HOLTZMANN, E . KRÄTZIG, a n d B . C . GRABMAIER

Influence of Mg Doping and Composition on the Light-Induced Charge Transport in LiNb0 3 G . - H . WANG, M . - K . TENO, D . - X . SHEN, Z H U , and L. Dou

C.-Y. YI,

Y . - Y . ZHOU, Y . - Y . L U ,

89

H . - W . WANG,

Y.-Z.

Positron Annihilation Lifetime and Doppler Broadening Studies of Electron-Irradiated Polypropylene

K1

Y u . DMITRIEV, V . K O S H K I N , a n d U . ULMANIS

Defocusing of Atomic Knock-Ons in Crystals with Low Local Symmetry of Structural Elements

Lattice

K7

properties

S . U . J E N a n d C. J . WENG

Thermal Expansion of ( F e M ^ B ^ i , Metallic Glasses (M = V, Cr, Mn)

99

P . CAPKOVA, M . MERISALO, M . L A I T I N E N , V . VALVODA, a n d L . DOBIASOVA

Thermal Vibrations and Thermal Expansion of ZrC0 8e Studied by X-Ray Diffraction

107

P . SVOBODA a n d P . VASEK

Low Temperature Thermal Conductivity of Metallic Glasses FexNiso-xBj,,

115

J . W . MOROTF a n d M . K&OSEK

Remarks on the Nature of the High Internal Friction Peak near Tg in Glassy Alloys K13 T . OHGAKU a n d N . TAKEUCHI

Temperature Dependence of the Effective Stress for KC1 Single Crystals K19

Surfaces,

interfaces,

thin films;

loicer-dimensional

systems

J . GEORGE, K . S . J O S E P H , B . P R A D E E P , a n d T . I . PALSON

Reactively Evaporated Films of Indium Sulphide

123

K . MEINEL, M . KLAUA, a n d H . BETHGE

Segregation and Sputtei Effects on Perfectly Smooth (111) and (100) Surfaces of Au-Ag Alloys Studied by AES

133

M . PATTABI, M . S . M . SASTRY, a n d V . SIVARAMAKRISHNAN

Studies on the Stability of Discontinuous Silver Films with Overlayers of AlaOa and Si0 2

145

5

Contents E . M . SHPILEVSKI a n d D . A . GORBACHEVSKII

Argon Ion Effect on Solid Phase Reaction in Copper-Tin, Copper-Antimony Films K23 F.

LUKES

Natural Surface Films on GeS

K27

J . SZATKOWSKI a n d K . SIERANSKI

Influence of Interface States on the Electrical Properties of Mg-Zn 3 P 2 Junctions K31 V . SVORCIK, V . R Y B K A , a n d V . M Y S L I K

Photoelectrochemical Etching of n-GaAs and n-InP

K35

N . S A S I , C . BALASTTBRAMANIAN, a n d SA. K . NARAYANDASS

Electrical Conduction in Germanium Dioxide Thin Films Localized

electronic

K41

states

I . V . MABCHISHIN, V . N . OVSYUK, a n d S . B . SEVASTIANOV

Deep Level Profiling Using an Admittance Spectroscopy Method. . . .

153

J . HFTBBIFIEK, V . C E C H , a n d A . BRABLEC

Determination of Trap Concentrations and Energy Levels in Insulatois and Semiconductors from Steady-State Space-Charge-Limited Currents. . . .

167

D . N E O G Y , A . K . M U K H E R J E E , a n d T . PUROHIT

Calculation of Electrostatic Crystal Field Parameters of Rare Earth Hydrated Single Crystals

173

K . K A W A B A T A , T . SEIYAMA, S . OKUDA, a n d Y . SHONO

Thermally Stimulated Exo-Electron Emission and Thermally Stimulated Luminescence of Irradiated «-A1203 Powder Electronic

transport;

181

superconductivity

M . N . K H A N , M . A . HASSAN, a n d C . A . HOGARTH

The Electronic and Optical Properties of Germanium Tellurite Glasses Containing Various Transition Metal Oxides 191 G . KLTJGE a n d J . SCHMAL

On the Application of the Ordinary and Photoconductivity Meyer-Neldel Rule to Amorphous Ge^Se^/Te^ Films K47 B . R . S I N G H , H . S . KOTHARI, 0 . P . DAGA, J . K . SINGH, G . S . T . R A O , J . D . J A I N , a n d W . S . KHOKLE X-Ray Diffraction and EDS Analysis of Y 1 Ba 2 Cu 3 0 9 _j / Superconducting

Compound

K53

K . BENTE a n d D . SIEBERT

E P R Investigations on High Temperature Superconducting YBa 2 Cu 3 0 7 _j; Magnetic

properties;

K57

resonances

T . T . DUNG, N . P . T H U Y , N . M . HONG, a n d T . D . H I E N

Anomaly in the Magnetic Properties of the YCo4B Compound

201

6

Contents

YAN-ZHCWG ZHANG

Magnetic Instability of Metallic Glass (Fe0_,Ni0 33Co0 55Cr0 „j^sSisBji- I I . Irreversible Magnetic Permeability Decay with Respect to Demagnetization

207

Y . SRINIVASAVA R A O a n d C . S . SUNANDANA

R . A . KOSII&SKI

Characterization of Diamagnetically Substituted (Na + , Te 4+ , CI") Lithium Ferrite

217

On the Stabilization of a Vertical Bloch Line Pair in a Domain Wall in an Ion-Implanted Garnet Film

227

Y . F . L I , L . HEDMAN, a n d Ö . RAPP

Magnetic Susceptibility of Amorphous Cui-^Y^ Alloys

233

S . ROTH a n d G . STEPHANI

Influence of the Melt Temperature on the Formation of Soft Magnetic Properties of an Amorphous Fe lft Ni 40 P 14 B 6 Alloy K61 A . H . W A F I K a n d S . A . MÄZEN

Effect of Mg-Fe Replacement in the System Mg x Zn 0 3Fe2.7 _ x 04+s on Barkhausen Jumps K65 S . LIGENZA, B . PALUCHOWSKA, a n d M . K O N W I C K I

Neutron Diffi action Studies of 0.2 Titanium Substituted Lithium Ferrite K71 L . VATSKICHEV a n d M . VATSKICHEVA

I

Relations between Some Galvanomagnetic and Magnetic Properties of Thin Ferromagnetic Films K75 F . YASSIN, V . CHRISIOPH, a n d L . J A H N

On the Determination of the Curie Temperature of Anisotropic Fenomagnets K79

Dielectric

and optical

properties

J . EHLERT, F . K . HÜBNER, a n d W . SPERBER

Micromagnetics of Cylindrical Pal tides

239

D . S . DOMANEVSKII, S . V . ZHOKHOVETS, a n d M . V . PROKOPENYA

1.1.

RESHINA

Peculiarities of Radiative Recombination in Gallium Arsenide Doped with Shallow Donors and Acceptors

249

Raman Study of Disoider in Laser-Annealed I I I - V Semiconductois. . .

261

B . D . B H A S I N , S . P . K A T H U R I A , a n d S . V . MOHARIL

Some Peculiarities of Photo-Transfei Thermoluminescence in LiF-TLD 100

271

Contents

7

E . Z . KATSNELSON a n d A . G . KAROZA

On the Iireversibility of the Processes duiing Photomagnetization of Ferrites

277

S . K I S H I D A , K . M A T S U U E A , H . M O R I , T . Y A N A G A W A , I . TSURTTMI, a n d C . H A M A G U C H I

The 2.5 eV Emission Band in the Se-TVeated ZnSe Crystals

283

R . K . G A R T I A , S . J . S I N G H , a n d P . S . MAZUMDAR

Symmetiy Factor and Order of Kinetics in Thermally Stimulated Luminescence 291 L . W E R N E R a n d J . W . TOMM

Photoluminescence in p-Hg 042 Cd 0 58Te

K83

H . K R E S S E a n d W . WEISSFLOG

Strong Antipaiallel Correlation in Liquid Crystalline Esteis with Lateral Groups K89 G . C. BHAB a n d N . P . GHOSH

Broadband Tuning in an Infrared Parametric Oscillator

K93

S . PAKEVA a n d R . DAFINOVA

The Electroluminescence of ZnS-Pb, Cu, Br Phosphors A. DE

ani

K97

K . V . RAO

Dielectric Properties of Synthetic Quartz Crystals Iiradiated with y-Rays or X-Rays under a High Electric Field K101 B . T . DESHMUKH, S . V . BODADE, a n d S . V . MOHARIL

Thermoluminescence in Synthetic Langbeinite Device-related

K107

phenomena

D . K I N D L a n d J . TOTJSKOVA

Charge Transport Study in Thin Film Au-CdTe Schottky Diodes

297

B . R H E I N L Ä N D E R , R . H E I L M A N N , a n d G . OELGART

Determination of Temperature-Dependent InGaAsP/InP Double-Heterostructures

Carrier Losses in

1.3 (Jim

K113

Pre-Printed Titles of papers to be published in the next issues of physica status solidi (a) and physica status solidi (b)

physica status solidi (a) is indexed in Current Contents/Physical, Chemical & Earth Sciences.

Al

9

Contents

Systematic List Subject classification:

Corresponding papers begin on the following pages (pages given in italics refer to the principle subject classification):

61.10 61.1 4 61.40 61.50 61.55 61.60 61.70 61.80 62.20 62.40 63.20 63.50 64.75 65.70 66.30 66.70 68.40 68.45 68.48 68.55 71.55 71.70 72.1 5 72.20 72.40 72.80 73.30 73.40 73.60 74.70 75.25 75.30 75.50 75.60 75.70 75.80 76.30 77.20 77.40 78.20 78.30 78.40 78.45 78.55 78.60 78.65 78.70 79.20 79.75 85

17, 25, 31, 41 49 11 K53 17 217 49, 89, K1 57,67, 73, 81, K7, K23 K19 K13 107 261 133 99,107 57, K23 115 133 K35 K23 11, 57, 123,133, K27 153,167,181, 249 173 115, K75 167 89, 277, K31, K47 191, K7 297, K31 153, K113 145, 297, K41 K53, K57 K71 201 207, 217, 233, K61, K71, K79 227, 239, K61, K65 K75 99 67, 191, K57 K89, K101 K89, K101 89, 277, K93 11, 191, 261 K107 K113 249, 283, K83 181, 271, 291, K97, K107 123, K27 81, Kl, K35 133 181 297, K113

10 51.1 51.2 51.3 51.4 . . . . . . . S1.61 S5.ll 56 57 57.1 1 57.12 S7.16 58 58.1 1 58.12 58.1 3 58.1 5 58.1 6 S9.ll 510 S10.1 S10.15 511 511. 1 511.2 512

Contents 17, 115, 207, K13, K61 49, 201, 207, 233, K13, K61, K75 133, 145, K23 201, 233, K75 17, 99, 107 11, 81 K23 K31 73, 81, 261, K35, K113 249, 261, K35 K93, K113 57, 123, K7, K27, K47 K97 283, K93 297 K83 K93 271, K19 K79 145, 181, K41, K101 191, K53, K.57 K107 89 217, 227, 277, K65, K71 67, 173, K l , K89

Contents of Volume 106 Continued on Page 807

Original

Papers

phys. stat. sol. (a) 106, 11 (1988) Subject classification: 61.40 and 68.55, 78.30; S5.ll Instituto de Electrónica de Comunicaciones (a), Instituto de Ciencia de Materiales "Sede A"1) (b), and Instituto de Optica "Daza de Valdés"2) (c), Consejo Superior de Investigaciones Madrid

Científicas,

Low Pressure Chemical Vapour Deposition Amorphous Silicon Behaviour under Annealing By G . PASTOB ( a ) , P . TEJEDOR ( a ) , I . J I M É N E Z ( a ) , E . DOMÍNGUEZ ( a ) , M . TORRES ( b ) , a n d J . V . GARCÍA-RAMOS (C)

Four types of amorphous silicon materials are grown in a low pressure chemical vapour deposition (LPCVD) system and their differences in colour, adherence, smoothness, as well as crystallinity of the derived materials are investigated as a function of annealing temperature. Experimental results indicate that amorphous silicon growth can actually occur, either through an heterogeneous mechanism on the substrate surface or through homogeneous nucleation in the vapour phase. In general, surface grown amorphous silicon renders high quality polysilicon after annealing. This is not the case for amorphous silicon nucleated in the vapour phase, which produces poor quality polysilicon under similar temperature conditions. Vier Arten von amorphem Siliziummaterial werden in einem Niedeidruck-CVD (LPCVD)-System hergestellt und ihre Unterschiede sowohl in Farbe, Haftfestigkeit, Glattheit als auch hinsichtlich ihrer Kristallinizität als Funktion der Temperungstemperatur untersucht. Die experimentellen Ergebnisse zeigen, daß Wachstum von amorphem Silizium tatsächlich auftreten kann, entweder über einen heterogenen Mechanismus auf der Substratoberfläche oder über eine homogene Keimbildung in der Dampfphase. Im allgemeinen ergibt oberflächengewachsenes amorphes Silizium nach Temperung Hochqualitätspolysilizium. Dies ist nicht der Fall für amorphes Silizium mit Keimbildung in der Dampfphase, das Polysilizium mit geringer Qualität unter ähnlichen Temperaturbedingungen liefert. 1. Introduction Polycrystalline silicon remains one of t h e m o s t c o m m o n l y used materials i n integrated circuits t e c h n o l o g y . A m o n g t h e m e t h o d s applied t o polysilicon growth, t h e l o w pressure chemical vapour deposition (LPCVD) t e c h n i q u e is t h e m o s t w i d e l y used. I n t h i s t o p i c w e h a v e published several papers [1 t o 3]. On t h e o t h e r hand, a n u m b e r of papers can be f o u n d i n literature, where studies on t h e structure, morphology, and electric properties of polysilicon layers grown b y L P C V D are reported [4 t o 6]. According t o t h e s e studies, polycrystalline silicon layers grown b y L P C V D a t temperatures a b o v e 6 0 0 °C are generally more stable t h a n t h o s e grown a t lower temperatures and recrystallized afterwards, since annealing w a s t h o u g h t t o lead t o uncontrolled crystallization. H o w e v e r , m a n y authors [7 t o 12] h a v e e x a m i n e d t h i s question and have concluded t h a t o n l y recrystallized a m o r p h o u s silicon offers t h e highest q u a l i t y — i n t e r m s of structural perfection and surface s m o o t h n e s s — t h a t certain applications require. *) Serrano 144, 28006 Madrid, Spain. 2 ) Serrano 121, 28006 Madrid, Spain.

12

G . PASTOR, P . T E J E D O R , I . J I M É N E Z , E . DOMÍNGUEZ, M . TORRES, a n d J . V . GARCÍA-RAMOS

Nevertheless, when using the LPCVD technique to grow polysilicon, it is not only possible to deposit amorphous silicon below 600 °C, but to deposit it at higher growth rates [13], or greater gas flows and pressures [14], using much higher temperatures. Furthermore, it will be demonstrated in the experiments described below that a large variety of amorphous silicon materials can be obtained with clear differences in colour, smoothness, crystalline structure, etc. We will also see that only when amorphous silicon is produced under optimal growth conditions, its recrystallization renders polysilicon of higher quality than the directly grown polycrystaliine material. The aim of this paper is to study how different types of amorphous silicon behave under annealing. They can be classified according to their colour in metallic, grey, black, and ochre, from higher to lower quality. I t will be examined how a series of parameters, such as smoothness, adherence, and transition to crystallinity, that characterize and differentiate them, vary with annealing conditions. A Talystep profilometer will be used to see the differences in smoothness in the four materials considered. Changes in adherence to the deposition substrate will be studied by examining the tendency of the as-grown a-silicon layers to peel off. The transition from amorphous to crystalline silicon that takes place as annealing progresses is investigated by means of Raman scattering spectrometry. 2. Experimental and Results All experiments were performed in a conventional "hot-wall" LPCVD system. [100] orientation, 2 " diameter monocrystalline silicon wafers, covered with 250 nm thick thermally grown Si0 2 , were used as deposition substrates. Epitaxial quality, and resistivity larger than 150 Qcm, pure SiH 4 — with no other gas present for transport or dilution — was used in all experiments. We will study the behaviour of metallic a-silicon under annealing as well as the behaviour of less common types of amorphous silicon materials under annealing. Metallic-type amorphous silicon was grown at 600 °C, with a gas flow of 10 seem (standard cubic centimetre per minute) and under pressures ^ 6 0 Pa. In the « (60 to 130) Pa range, the deposits are opaque grey. From «¿130 to « 2 6 0 Pa they gradually become black and for pressures over « 2 6 0 Pa ochre a-silicon is obtained. Growth rate increases considerably with pressure, as shown in Table 1. Table 1 Range of growth rate G (in nm/min) versus type of silicon (or pressure) and temperature T (°C)

Si (metallic) (p g 60 Pa)

Si (grey) (p as 60 to 130 Pa)

Si (black) (p as 130 to 260 Pa)

Si (ochre) (p ^ 260 Pa)

600 630

< 20 < 30

as 20 to 100 as 30 to 150

sa 100 to 600 « 150 to 700

>600 >700

Table 2 Colour change after annealing of different as-grown amorphous silicon as-grown

metallic

grey

black

ochre

800 °C 900 °C 1000 °C

metallic metallic metallic

light blue-grey blue-grey blue-grey

lightly grey-black grey-black grey-black

beige-ochre beige beige

Low Pressure Chemical Vapour Deposition Amorphous Si Behaviour under Annealing

13

A second series of experiments was performed at 630 °C. For pressures below « 6 0 Pa polycrystalline silicon is obtained, whereas for higher pressures only amorphous silicon can be grown. As pressure increases, the amorphous silicon colour changes from gray to black and from black to ochre, as it was previously observed at 600 °C. However, growth rates are slightly higher at 630 °C. All the wafers were annealed at 800, 900, and 1000 °C. The change in colour occured as a consequence of annealing the amorphous silicon grown at 600 °C can be seen in Table 2. It is evident from this Table 2 that the original colour tends to become lighter, even when the basic tone remains. Fig. l a shows the smoothness profiles recorded with a Talystep profilometer for the four types of amorphous silicon considered — metallic, grey, black, and ochre — prior to annealing. As was expected, the metallic-type a-silicon has the smoothest surface, while the ochre material exhibits the roughest. The smoothness profiles ochre

black

gray

metal 50jim

i

T

1p.m

i

ochre

black

gray

b

c.

o>

metal SOjLrn

o Fig. 1. Smoothness of metallic, grey, Qj black, and ochre amorphous silicon. £ a) As-grown, a-silicon, b) 1000 °C annealed a-silicon

14

G. PASTOR, P. TEJEDOR, I. JIMÉNEZ, E. DOMÍNGUEZ, M. TORRES, and J. V. GARCÍA-RAMOS Table 3 Tendency of the a-silicon layer to peel off from the deposition substrate

T (°C)

Si (metallic)

Si(grey)

Si (black)

Si(ochre)

as-grown 800 900 1000

difficult very difficult very difficult very difficult

easy difficult difficult very difficult

very easy easy easy easy

very easy easy easy easy

after annealing at 1000 °C of the same four samples are shown in Fig. l b . I t can be seen that the annealing process enhances greatly the smoothness of metallic a-silicon and produces a remarkable improvement in the quality of gray a-silicon. However, it does not alter much that of black and ochre a-silicon. The tendency of the deposited layers to peel off gives an idea of their adherence to the substrate, as shown in Table 3. The metallic-type a-silicon has proved to have a good adherence in all cases. The as-grown grey a-silicon material can be peeled off easily, but its adherence to the deposition substrate increases with annealing, especially t

i

l

i

1

i

a

p)

;

•Q .N CJ t

/ i i i ?i i

//

y*" >1

1

1

i

1

i

i

1

!

c

¡i

i ji -

ii ii

.i 1

?

? 1 . (tf*

• 450

;

.i

¡i 560

6U0

U80

L,

560 h(cm-1) -

Fig. 2. Raman spectra of metallic, grey, black, and ochre amorphous silicon, a) As-grown a-silicon. b), c), and d) 800 °C, 900 °C, and 1000 °C annealed a-silicon, respectively. Metal, grey, . — — • black, ochre

Low Pressure Chemical Vapour Deposition Amorphous Si Behaviour under Annealing

15

at 1000 °C. On the other hand, both black and ochre a-silicon materials show very poor adherence, although it improves slightly as a result of annealing. As is well known, in the case of crystals, the Raman scattering spectrometry is sensitive to the symmetry of the environment of the structural units; so, more neat spectra are expected when this symmetry is well defined. Therefore, the Raman scattering spectrometry is a potential technique to study the evolution from amorphous to crystalline structures. Sharp peaks are observed in the case of crystalline films, while wider peaks with long tails are observed in the case of amorphous films. This technique has the advantage that a continuous evolution from amorphous to crystalline structures is exhibited. Raman scattering spectrometry has been used to study the amorphous silicon transformation into polysilicon. The Raman spectra were obtained with the aid of a Jobin 1000 (514.5 nm) spectrometer. Fig. 2a shows the Raman spectra for the asgrown metallic, grey, black, and ochre amorphous silicon materials. Fig. 2 b, c, and d, show the Raman spectra for the same materials after annealing at 800, 900, and 1000 °C, respectively. The spectra of the annealed metallic and grey a-silicon materials resemble the more that of crystalline silicon, the higher the annealing temperature is. On the other hand, when black or ochre a-silicon are annealed, the quality of the crystalline materials produced is always lower than the quality of reerystallized metallic and grey a-silicon, even for the highest annealing temperature studied (1000 °C). 3. Discussion Our experimental results reveal a clear difference in behaviour between metallic a-silicon and the black and ochre a-silicon materials. Grey a-silicon is considered to be intermediate or in a transition state in between. Besides colour, which was useful as an identification source, the main difference between the four types of a-silicon considered is the large variation in growth rate found. Such a variation accounts for a change in the growth mechanism. Metallic a-silicon growth takes place on the growing solid surface through a heterogeneous mechanism, while black and ochre a-silicon growth occurs through homogeneous nucleation in the vapour phase. Grey a-silicon would be an intermediate case in which surface growth predominates but vapour phase nucleation exists to some extent. This explanation can be better understood by taking into account the differences in adherence to the deposition substrate observed for each of the four types of a-silicon prior to annealing. It was pointed out above that metallic a-silicon layers show good adherence to the deposition substrate. Such observation agrees with a layer growth taking place through the well-known heterogeneous mechanism, that includes adsorption of the reactant molecules on the growing solid surface, solid state diffusion of the same species to active centres on the surface, surface reactions leading to silicon formation, which incorporates the lattice, and desorption of the reaction products from the surface. In this way, a continuous growth of silicon layers occurs by lateral step movement [15]. Although this mechanism has conventionally been used to explain crystal growth, it can also be applied to amorphous material growth, bearing in mind that due to lower operation temperatures surface diffusion is slower, thus hindering crystalline order. However, the poor adherence exhibited by black and ochre a-silicon is due to silicon vapour phase nucleation followed by "drizzling" over the surface, where it accumulates without becoming part of the substrate lattice. The smoothness characteristics of the four types of a-silicon correlate with the above-described growth mechanisms. Growth through the heterogeneous mechanism is responsible for the high smoothness found in the as-grown metallic a-silicon, whose

16

G. PASTOR et al. : LPCVD Amorphous Si Behaviour under Annealing

quality improves greatly with annealing. Neither the black nor the ochre a-silicon materials show very smooth surfaces, even after annealing as silicon nucleated in the vapour phase does not become structurally bonded to the surface and cannot crystallize adequately during annealing. The Raman spectra shown in Fig. 2 reveal that complete recrystallization is never achieved for black and ochre a-silicon, in good agreement with the smoothness characteristics of these materials. Therefore, the existence of two basic types of a-silicon is evident. One of them grows through an heterogeneous mechanism and the other one by homogeneous nucleation in the vapour phase. The second mechanism agrees with Ho and Breiland [16], who observed the presence of Si 2 in the vapour phase and also with Coltrin's model predictions [17], which consider that the vapour phase plays the most important role during growth. Furthermore, polysilicon produced by a-silicon recrystallization is of higher quality in terms of structural perfection, smoothness, etc. than hightemperature grown polycrystalline silicon only in the case of metallic type a-silicon, but not in the case of grey, black, or ochre a-silicon. 4. Summary We have seen that there exist four types of amorphous silicon materials — metallic, grey, black, and ochre — although they can be divided into two groups. The first group includes metallic a-silicon and corresponds to a heterogeneous growth mechanism, while the second group, in which black and ochre a-silicon are included, corresponds to a homogeneous vapour phase growth. Grey a-silicon is considered to grow through a combination of both mechanisms. I t cannot be concluded that polysilicon produced by annealing of a-silicon is of higher quality than directly grown polycrystalline silicon, as a rule. Such a statement is true when growth takes place through a heterogeneous mechanism, but not when it occurs in the vapour phase, that is to say, only for metallic a-silicon. References [ 1 ] C. DOMÍNGUEZ, G. PASTOR, a n d E . DOMÍNGUEZ, V a c u u m 3 7 , 4 0 7 ( 1 9 8 7 ) . [ 2 ] C. DOMÍNGUEZ, G. PASTOR, a n d E . DOMÍNGUEZ, J . E l e c t r o c h e m . S o c . 1 3 4 , 1 9 9 ( 1 9 8 7 ) . [ 3 ] C. DOMÍNGUEZ, G. PASTOR, a n d E . DOMÍNGUEZ, J . E l e c t r o c h e m . S o c . 1 3 4 , 2 0 2 ( 1 9 8 7 ) .

[4] R. S. ROSLER, Solid State Technol. 20, 63 (1977). [5] W. A. BROWN and T. I. KAMINS, Solid State Technol. 22, 51 (1979).

[ 6 ] T . I . KAMINS, J . E l e c t r o c h e m . S o c . 1 2 7 , 6 8 6 ( 1 9 8 0 ) . [ 7 ] G. HARBEKE, L . KRAUSBAUER, E . F . STEIGMEIER, A . E . WIDMER, H . F . KAPEN, a n d G. NEU-

GEBAUER, Appl. Phys. Letters 42, 249 (1983).

[ 8 ] E . KINSBRON, M. STERNHEIM, a n d R . KNOELL, Appl. P h y s . L e t t e r s 4 2 , 8 3 5 ( 1 9 8 3 ) . [ 9 ] G. HARBEKE, L . KRAUSBAUER, E . F . STEIGMEIER, A . E . WIDMER, H . F . KAPPERT, a n d G. NEUGEBAUER, R C A R e v . 4 4 , 2 8 7 ( 1 9 8 3 ) . [ 1 0 ] M. T . DUFFY, J . T . ME GINN, J . M. SHAW, R . T . SMITH, R . A . SOLTIS, a n d G. HARBEKE,

RCA Rev. 44,313 (1983).

[ 1 1 ] G. HARBEKE, L . KRAUSBAUER, E . F . STEIGMEIER, A . E . WIDMER, H . F . KAPPERT a n d G. NEUGEBAUER, J . E l e c t r o c h e m . Soc. 1 3 , 6 7 5 ( 1 9 8 4 ) . [ 1 2 ] F . S. BECKER, H . OPPOIZER, I . WEITZEL, H . EICHERMYLLER, a n d H . SCHABER, J . appl. P h y s . 5 6 , 1 2 3 3 (1984).

[13] J . P. DUCHEMIN, Thesis, University Caen, 1979.

[ 1 4 ] G. PASTOR, C. DOMÍNGUEZ, E . LORA-TAMAYO, a n d E . DOMÍNGUEZ, A n a l e s F i s . Ser. B 8 1 , 1 1 4 (1985).

[15] J . BLOEM, J . Crystal Growth 50, 581 (1980). [16] P. Ho and W. G. BREILAND, Appl. Phys. Letters 44,51 (1984).

[ 1 7 ] M. E . COLTRIN, R . J . K E E , a n d J . A . MILLER, J . E l e c t r o c h e m . S o c . 1 3 1 , 4 2 5 ( 1 9 8 4 ) .

(Received July 23, 1987; in revised form December 7,1987)

M. POLCABOVÌ. et al. : Lattice Parameters of Fe-Si Alloy Single Crystals

17

phys. stat. sol. (a) 106, 17 (1988) Subject classification: 61.55; 61.10; S l . l ; S1.61 Institute of Physics, Czechoslovak Academy of Sciences, Prague1) (a) and Institute of Physics, Polish Academy of Sciences, Warsaw (b)

Lattice Parameters of Fe-Si Alloy Single Crystals By M . POLCAROVA ( a ) , K . GODWOD ( b ) , J . B ^ K - M I S I U K ( b ) , S . KADEÖKOVÄ a n d J . BRÄDLER (a)

(a),

Lattice parameters of single crystals of pure iron and three Fe-Si alloys with Si concentration < 7 a t % are measured using three different X-ray techniques, namely the ratio, Bond and triple crystal diffractometer methods. The lattice parameter of pure iron is found to be a = (0.286652 + + 0.000002) nm. In Fe-Si alloys it decreases with increasing Si concentration with the slope Aa/Ac = —0.000069 n m / a t % Si. The results obtained by the three methods are compared with respect to the complexity of experimental techniques and requirements on the crystal perfection. Phenomena affecting the accuracy are discussed. Unter Anwendung von drei verschiedenen röntgenographischen Verfahren, nämlich der Methode der Verhältnisse, der Bond-Methode und dem Dreikristalldiffraktometerverfahren, werden die Gitterkonstanten der Einkristalle von Reineisen und drei Fe-Si-Legierungen (Si-Gehalt < 7 at%) gemessen. Die Gitterkonstante des reinen Eisens wird zu a = (0,286652 + 0,000002) nm bestimmt. Für die Fe-Si-Legierungen nimmt sie mit zunehmendem Si-Gehalt ab, wobei Aa/Ac = = —0,000069 n m / a t % Si. Die durch die drei Methoden gewonnenen Resultate werden mit Rücksicht auf die Kompliziertheit der experimentellen Verfahren und die Ansprüche auf die Vollkommenheit der Kristalle untereinander verglichen. Die Faktoren, die die Genauigkeit der Messung beeinflussen, werden diskutiert.

1. Introduction The precise knowledge of lattice parameters is important for the theoretical treatment of mechanical and other physical properties of materials and can be useful for many practical applications. Lattice parameters of solid solutions depend mainly on the type and concentration of the solute. Silicon is one of the less numerous substitutional solutes which lower the lattice parameters of steels [1]. The dependence on the Si concentration is linear with a slope change of 10 at% where the superstructure begins to play an important role [2]. Lattice parameters of Fe-Si alloys were measured by a number of authors. Most measurements were made on polycrystalline or powder samples (e.g. [3 to 6]), only few were done on single crystals [7, 8]. It can be assumed that the results from polycrystalline and powder samples may in principle differ from those on single crystals owing to the following effects. The higher density of crystal defects present in polycrystals can affect the homogeneity of the Si distribution, e.g. through segregation at grain boundaries and partical surfaces [9]. Therefore the measured parameter can correspond to a Si concentration different from the mean value found by chemical analysis. Some types of defects (e.g. non fully removed stresses) can shift the measured value or lower the precision through broadening of the diffraction line. Even if an ideal polycrystalline sample is available, i.e. without stresses and having a suitable !) Na Slovance 2, 18040 Praha 8-Liben, ÖSSR. 2

physica (a) 106/1

18

M. Polcabova, K. Godwod, J. B^k-Misiuk, S. KadeCkova, and J. Bradler

particle size, the attainable precision is lower than that of single orystal techniques. It appears therefore to be useful to compare the results of both types of measurements. A number of techniques have been developed for the measurement of lattice parameters on single crystals (see e.g. the review paper [10]). With the frequently used Bond method [11] a precision of several ppm can be achieved, in refined versions one order of magnitude better. Differential methods allow to determine lattice parameter variations with a sensitivity of Ad/d « 10~8. Most of these methods are applicable only to high quality single crystals. Mosaic crystals can be studied using the ratio method [8] with a moderate precision (Adjd « 10 -4 ). The aim of this work was to measure precisely lattice parameters of single crystals of Fe-Si alloys. Three different techniques were applied and the results were compared with each other as well as with previous results of other authors. 2. Experiments 2.1 Samples

Sample A was a high-purity iron single crystal. The content of impurities was c c « 5 to 10, c0i! « 26 to 36, cNs « 17 to 27, other impurities c < 15 ppm [12]. The single crystal (4 mm in diameter, growth direction [001]) was grown by the strain anneal method [12]. The sample of dimensions « 2 . 5 X 12 X 1.6 mm3 with the largest surface parallel to the (100) plane was prepared by chemical polishing. The crystal quality was tested by X-ray double crystal reflection topography (the arrangement used is described in [13]). No low-angle subgrain boundaries were observed in the sample, the dislocation density was estimated to be (jxT\xf the kinematical limit (14) is reached (see Fig. l b ) .

Fig. 1. Schematic plots of amplitude dependences of integrated reflectivity for the cases of a) short b) long wavelengths. g= \HW\, g1 =

= (W>

& = (7iTM\ g3 = HSl/Ks

Dynamical and Kinematical X-Ray Diffraction in Crystals Disturbed by Vibrations

29

In general, when the kinematical regime is reached, the integrated reflectivity does not change further. But if increasing the deformation amplitude, the angular width of the region occupied by the satellites, AH/H « 4e0, can exceed the divergence of the incident radiation Q. In this case, the observed integrated intensity does not correspond to the integrated reflectivity and decreases as W _ 1 (see Fig. 1). As a rule, in a crystal a standing wave is excited whose amplitude depends on time as W = W'st cos cosi, where W st is the amplitude of the standing wave, eos its circular frequency. What we need now is to make trivial time-averaging in (3), (4), (9), (12), and (16). Then Wis substituted by IF st and coefficients of order unity appear at the powers of |/iH / s t |. 3. Concluding Remarks The condition of kinematical scattering (12) is to be compared with the usual criterion (17) where L is the dimension of the region of coherent scattering. The latter value can be estimated if it is assumed that the variation of the deflection from the exact Bragg direction which occurs at distance L equals the dynamical width of a reflection, S8p, Then

4 |Ve| L = 80p . L

_

Airg 2K\

\HW\'

and from (17) we find

\HW\>(^rJ-

L^, where L ^ is the X-ray penetration depth, then the secondary radiation intensity is proportional to the total absorbed energy of X-rays. Computer simulation of the threewave case (444, 335, Bragg geometry, CuK a , Si) shows that the angular dependence of the photoelectron emission yield can be described as a repulsion interaction of two crossing two-wave maxima. New possibility of observing the two-wave X-ray standing waves is discussed where the angular dependence of induced second reflected wave with a small intensity is analysed instead of the secondary radiation yield within the total reflection domain for the first reflected wave. Gleichungen zur Berechnung der Winkelabhängigkeit der sekundären Strahlungsausbeute (Photoelektronenemission oder Fluoreszenzstrahlung) unter den Bedingungen der dynamischen Röntgenmehrfaehbeugung werden erhalten. Für eine geringe Ausbeutetiefe Lyi ist die Intensität der Sekundärstrahlung proportional zur Intensität der Röntgenstrahlen an den Atomplätzen einer Oberflächenschicht des Einkristalls. Wenn Ly\ > Lx, wobei L^ die Röntgeneindringtiefe ist, ist die sekundäre Strahlungsintensität proportional zur gesamten absorbierten Energie der Röntgenstrahlen. Computersimulation des Dreiwellenfalles (444, 335, Bragg-Geometrie, CuK a , Si) zeigt, daß die Winkelabhängigkeit der Photoelektronenemissionsausbeute als repulsive Wechselwirkung zweier sich schneidender Zweiwellenmaxima beschrieben werden kann. Neue Möglichkeiten zur Beobachtung der stehenden Röntgenwellen im Zweiwellen-Fall werden diskutiert, wobei die Winkelabhängigkeit der zweiten induzierten reflektierten Welle mit einer geringen Intensität anstatt der sekundären Strahlungsausbeute innerhalb der Gesamt-Reflexionsdomäne für die erste reflektierte Welle analysiert wird. 1. Introduction T h e X - r a y standing w a v e analysis of the subsurface layer of semiconducting crystals has been widely used in recent years (see, e.g., [1 t o 6]). I t consists in t h e registration of t h e angular dependence of t h e yield of secondary radiation (SR) such a s p h o t o electron emission or fluorescence radiation, under t h e conditions of d y n a m i c a l X - r a y diffraction in single crystals. T h e a m p l i t u d e E of t h e electric field of X - r a y s at a n a t o m i c site is t h e superposition of t w o plane w a v e s : t h e entrance one E0 and t h e reflected one En. W i t h i n t h e angular d o m a i n of t o t a l reflection t h e a m p l i t u d e s of t h e s e w a v e s h a v e nearly equal values. A s a result a s t a n d i n g w a v e arises. T h e n u m b e r of photoelectrons or fluorescence quanta e m i t t e d b y a t o m s , is proportional t o \E\2 a n d d e p e n d s strongly on t h e p h a s e of t h e relation E h IE 0 . T h a t is w h y t h e angular dependence of t h e photoelectron emission differs essentially f r o m the angular dependence of t h e X - r a y reflection t h a t is equal t o \En\2l\E0\2. pl. Kurchatova, SU-123182 Moscow, USSR.

32

V . G . KOHN

Fig. 1. The scheme of three-beam X-ray diffraction and the rotation axes of a crystal

The phase sensitivity of the X-ray standing wave method makes it very useful for studying the position of impurity atoms at the surface (adsorption) and in the bulk of a crystal near the surface. The method also allows to measure the displacements due to the crystal lattice relaxation after ion implantation or due to the incommensurability of lattice parameters in layer and substrate. Up to now the nature of the arising X-ray standing wave and the motion of its nodes relative to the atomic planes with varying deviation from the Bragg angle is known well enough only for the two-beam case of X-ray diffraction. In the case of multiple diffraction the electric field which is the superposition of several plane waves, depends essentially on two mutually perpendicular angular deviations of the direction of the entrance beam from the direction that satisfies exactly several Bragg conditions. If the direction of the entrance beam is fixed, then the intensity of both reflected beams and the photoelectron emission change with crystal rotation around two axes, i.e. the axis 6 (rotation in the plane perpendicular to the crystal surface) and the axis q> (rotation in the surface plane), as is shown in Fig. 1. The analysis of the two-dimensional angular dependence allows to localize two coordinates of an impurity atom site. Hence the measurement of S R yield under the conditions of multiple diffraction gives additional valuable information. In a single crystal one obtains the possibility to study the motion of two-dimensional stationary waves with the change of the entrance beam direction. To solve these problems it is necessary to develop further the theory of multiple X-ray diffraction. This is the aim of the present paper. In the following section the derivation of the general equations is given. The specific example of the photoelectron emission in the case of three-beam (444, 335) diffraction of CuK a radiation in a Si single crystal is analyzed theoretically in Section 3. In Section 4 a new possibility of using two-wave standing waves without the measurement of S R yield is discussed in brief. 2. Derivation of General Equations Let the crystal be oriented with respect to the entrance beam such that two Bragg conditions (or more in the presence of additional crystal symmetry elements) are satisfied simultaneously for reciprocal lattice vectors hm . Then the amplitude of the electric field in a crystal has the form N-1 E(r, t) = e-< im» 2 Em {z) e ik« r , m=0

(1)

X-Ray Standing Waves under the Conditions of Multiple Diffraction

33

where N is the number of strong waves, Ifcjn — A'q -)- hmi is the wave vector of the entrance wave, z the coordinate along an inner normal w0 to the crystal surface. The transverse character of X-rays in a crystal is conserved because small additions of the order (1 — e) «s 10 -5 , where e is the dielectric function, can be neglected. Hence we may consider only two components of the vectors Em(z), namely, Em(z) = 2 Bms (2) «=

tt, o

where em„ and ema are the unit polarization vectors for the m-th wave which are perpendicular both to k m and to each other. The scalar amplitudes Ems(z) satisfy a set of equations derived from the Maxwell equations. In this procedure we can neglect the second derivatives of the amplitudes with an error not exceeding (1 — s), if the parameters ym = femn0/|fem| are not too small. Then the set of equations has the form ~: 3

% az

=

*

£ \.Xmm'

"^m^iMi»'] Em's- •

Aym m-S'

(3)

Here Xmm' = 3im»'(®»w®«»v) (in dipole approximation), %mm- is the Fourier transform of the crystal polarizability % = %r + iyA with the reciprocal lattice vector hm — hm', A the wavelength, k2 — kl

Bl|, where Pm = yal\ym\ and ocml is a coefficient in (4). The displacement of a R T D R centre from the point A0 = 0 on the line Aq> = 0 is equal to A6m = — |Xol (1 + Pm)IPmO