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VELOCITIES AND INTERNAL FRICTION OF DISLOCATIONS IN III-V COMPOUNDS
T. Ninomiya
To cite this version:
T. Ninomiya. VELOCITIES AND INTERNAL FRICTION OF DISLOCATIONS IN III-V COMPOUNDS. Journal de Physique Colloques, 1979, 40 (C6), pp.C6-143-C6-145.
�10.1051/jphyscol:1979629�. �jpa-00219045�
JOURNAL DE PHYSIQUE CoZZoque C6, suppldment ax n06, tome 40, j u i n 1979, page C6-143
V E L O C I T I E S A I ~ D INTEXNAL F R I C T I O N OF DISLOCATIONS I A
111-V
CaMP3UNDS T. NinomiyaCepartement o f Physics, U n i v e r s i t y o f Tokyo Bunkyo-ku, Tokyo 113, Japan
Resume.- Des mesures d i r e c t e s des v i t e s s e s de d i s l o c a t i o n dans l e s compos@s 111-V m o n t r e n t que l a v i - t e s s e de l a d i s l o c a t i o n B e s t beaucoup a f f e c t @ e p a r l e s impuretes des donneurs, e t q u ' e l l e e s t beau- coup p l u s p e t i t e que c e l l e de l a d i s l o c a t i o n a . La comparaison avec l a v i t e s s e de l a d i s l o c a t i o n v i s amene
a
c o n c l u r e que dans l e c r i s t a l de t y p e n, l a d i s l o c a t i o n B .?i 30' a l a m o b i l i t e l a p l u s l e n t e .A b s t r a c t . - D i r e c t measurements o f d i s l o c a t i o n v e l o c i t i e s i n 111-V compounds show t h a t t h e v e l o c i t y o f 3 - d i s l o c a t i o n i s g r e a t l y a f f e c t e d by donor i m p u r i t i e s and much s m a l l e r than t h a t o f a - d i s l o c a t i o n . Comparison w i t h t h e screw d i s l o c a t i o n v e l o c i t y l e a d s t o t h e c o n c l u s i o n t h a t i n n - t y p e c r y s t a l 30' B - d i s l o c a t i o n has t h e s l o w e s t m o b i l i t y .
1. I n t r o d u c t i o n . - I n v e s t i g a t i o n s o f d i s l o c a t i o n mo- D i s l o c a t i o n v e l o c i t i e s a r e shown i n f i g u r e 1 t i o n i n 111-V compounds have a f e a t u r e when compared f o r undoped ( n - t y o e ) GaAs and undoped InSb. The l a r g e w i t h t h e case of element semiconductors, because t h e r e d i f f e r e n c e o f t h e a - d i s l o c a t i o n v e l o c i t i e s , vn, from
-
a r e two k i n d s o f 60" d i s l o c a t i o n s i n t h e s p h a l e r i t e t h e B - d i s l o c a t i o n v e l o c i t i e s , v,, i s n o t i c e d . The ,..
s t r u c t u r e . They a r e c a l l e d a- and B- d i s l o c a t i o n s , a c t i v a t i o n energy a t h i g h s t r e s s e s i s weakly d e ~ e n -
2. Experimental R e s u l t s . - D i r e c t measurements o f d i s - l o c a t i o n v e l o c i t i e s have been done by double e t c h
which have an e x t r a h a l f p l a n e e n d i n g w i t h a row o f d e n t on s t r e s s r as
fi
w i t h a n e g a t i v e c o e f f i c i e n t group 111 and V atoms r e s p e c t i v e l y i n a c o n f i g u r a t i o n ( F i g . 2 ) .o f p e r f e c t d i s l o c a t i o n . T h i s d i f f e r e n c e i n t h e c o r e
T("C)
s t r u c t u r e causes d i f f e r e n c e i n t h e b e h a v i o u r s o f t h e s e 600 400 200 100 50
techniq'e. The d i s l o c a t i o n t y p e s (a, B 0' screw) i s ~ i1 : ~~ . ~dependence of d i s l o c a t i o n v e ~ o - ~ ~ ~ ~ ~ t ~ r ~
u s u a l l y d e t e r m i n e d by g e o m e t r i c a l c o n s i d e r a t i o n on c i t i e s i n undoped InSb/6/ a t s t r e s s T = 5 x 1 0 6 ~ / m 2 expanding l o o p s o f d i s l o c a t i o n /6/, and t h e assignment and GaAs /11/ a t T = 2 x 10' N/m2 /12/.
d i s l o c a t i o n s .
D i r e c t measurements o f d i s l o c a t i o n v e l o c i t i e s
1 0 - ~ have been made m a i n l y f o r InSb /1-6/ and GaAs /7-12,
4/, and some d a t a have been o b t a i n e d f o r InAs and
;aSb /13/. I n s o i t e o f some d i s c r e o a n c i e s among t h e
,.
r e s u l t s
r i s t i c s b y common d i f f e r e n t t o 111-V groups, com~ounds we f i n d : these some c h a r a c t e - a r e t h e
. -
m$ l o 6 ~>
l a r g e d i f f e r e n c e i n t h e v e l o c i t i e s between a- and B-
d i s l o c a t i o n s and t h e remarkable e f f e c t o f doping. 10 The purpose o f t h e p r e s e n t paper i s t o b r i e f l y
r e v i e w t h e e x p e r i m e n t a l r e s u l t s on d i s l o c a t i o n v e l o -
c i t i e s . 10-lo.
has been c o n f i r m e d by X-ray topography.
A t l o w s t r e s s e s t h e energy i n c r e a s e s more r a p i d l y
The s c a t t e r i n g o f d a t a f o r movement o f i n d i v i - with decreasing stress than extrapolation of the J;.
dual dis1orat;ons a t a g i v e n s t r e s s ranges from 10%
curve from high stress. The dislocation velocity can t o 40%, depending upon t h e d i s l o c a t i o n t y p e s : t h e suite often be described as
1
-
1 I GaAs I I- \
\ a
8 -
- P Screw
I I I I
s c a t t e r f o r 6- d i s l o c a t i o n i s much s m a l l e r than f o r
a - d i s l o c a t i o n . T h i s seems i m o l y t h a t a - d i s l o c a t i o n i s v = v o ( l + $ ) exo
c-W -+-I,
(1)more e a s i l y a f f e c t e d w i t h such a f a c t o r as c l i m b i n g . and more d e t a i l e d a n a l y s i s has been done by ? 4 6 l l e r / 1 4 /
1 2 3
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1979629
C6- 144 JOURNAL DE PHYSIQUE
f o r undoped GaAs by t a k i n g d i s s o c i a t i o n i n t o account. On t h e o t h e r hand, vg s t e e n l y decreases w i t h i n c r e a -
1
.o
1
2
3(stress
)J2(10' ~ j r n ~ f " ' Fig. 2 : A c t i v a t i o n energy E versus s t r e s s T f o r B- d i s l o c a t i o n i n undoped GaAs. : Erofeeva and Osipyan /4/,0:
Choi e t a l . /11/.I n f l u e n c e o f i m p u r i t y doping has been i n v e s t i - gated f o r GaAs /7,9-12/ and InSb /4,5/. As shown i n f i g u r e 3 f o r GaAs, va i s o n l y weakly dependent on t h e i m p u r i t y c o n c e n t r a t i o n below 10" cm'jboth i n D- and n-type c r y s t a l s .
lvO 1
0l8 10l6 10'61
0l8-
P-type n-type-
a
Concentration ( ~ r n - ~ )-
P-type n-type-
b
Carrier Concentration ( cm-3, Fig. 3 : V e l o c i t i e s (a) and a c t i v a t i o n energy (b) o f a- and B- d i s l o c a t i o n s i n GaAs as a f u n c t i o n o f c a r r i e r c o n c e n t r a t i o n a t 300°C and T = 1 0 7 ~ / m 2 . ( u ) : undoped. (Te) : Te-doped. Other n-type : Si-doped.p-type : Zn-doped. /12/.
s i n g donor concentration. The e f f e c t of doping i s considered t o be o f e l e c t r i c a l nature, because t h e d i s l o c a t i o n v e l o c i t i e s i n ~ i - d o p e d ' and i n Te-doped n-type c r y s t a l s f a l l on t h e same curves. For t h e h i g h c o n c e n t r a t i o n o f acceptors ( 2 3 x 1018cm-3) i t i s b e l i e v e d t h a t p r e c i p i t a t i o n may occur, p a r t l y because o f the sudden change i n t h e v e l o c i t i e s shown i n f i g u - r e 3 and p a r t l y because o f discrepancies among t h e data by d i f f e r e n t groups. I t i s a l s o l i k e l y t h a t i m p u r i t i e s p r e c i p i t a t e i n h i g h l y doped n-type c r y s t a l s (> 3 x 10'' cm- 3 ,
,
because sometimes 1 arger a c t i v a - t i o n energy i s obtained.Decrease i n v w i t h doping of donor i m ~ u r i t i e s B
has a l s o been found i n InSb (Fig. 4). I n strong con- t r a s t w i t h t h e case o f GaAs, va increase r a p i d l y w i t h Zn doping beyond 1 x lo1 c N 3 .
Fig. 4 : V e l o c i t i e s i n InSb as a f u n c t i o n of i m p u r i t y c o n c e n t r a t i o n a t 150' C and .r = 1.5 kg/mm2. n-type : Te-doped,Oa,0,3,
+
screw. p-type : Ge-doped,nay
I
B. p-type : Zn-doped, b a , AB,+
screw /4,5/The v e l o c i t y o f screw d i s l o c a t i o n vS has n o t been f u l l y i n v e s t i g a t e d . As shown i n f i g u r e 4, i n InSb vs i s n e a r l y equal t o v /4,5,6/. I n undoped GaAs vs has a l s o been estimated t o be roughly equal B t o v from t h e p e n e t r a t i o n r a t e o f d i s l o c a t i o n loop.
The a c t i v a t i o n energy o f screw d i s l o c a t i o n i s t h e B same as t h a t o f $ - d i s l o c a t i o n /6/. These r e s u l t s suggest t h a t vs i s n e a r l y equal t o vg, when v << vci
B To t h e a u t h o r ' s knowledge, i n t e r n a l f r i c t i o n which i s due t o k i n k motion i n 111-V compounds has been i n v e s t i g a t e d o n l y by Ohori and Sumino /15/.
They found t h r e e peaks i n InSb, which have t h e a c t i - v a t i o n energies 0.05, 0.08 and 0.36 eV r e s p e c t i v e l y . They a t t r i b u t e d the f i r s t two peaks t o l a t e r a l motion o f geometrical kinks. !Je may conclude t h a t t h e P e i e r l s
T. Ninomiya
energy f o r k i n k motion i s very small compared w i t h the formation energy o f a double k i n k .
3. Discussion.- According t o Haasen /16/, t h e e f f e c t of i m p u r i t y doping on t h e d i s l o c a t i o n v e l o c i t y comes from the r e d u c t i o n o f doubl e-kink formation energy due t o the charge on d i s l o c a t i o n . As shown i n f i g u r e 3, t h e a c t i v a t i o n energy o f a - d i s l o c a t i o n i s almost independent o f t h e i m p u r i t y c o n c e n t r a t i o n e x c e p t ' f o r h i g h doping o f acceDtors where p r e c i p i t a t i o n may a f f e c t t h e v e l o c i t y . The e l e c t r o n i c l e v e l associated w i t h a - d i s l o c a t i o n i s supposed t o l i e i n t h e conduc- t i o n band o r very near t h e bottom o f the conduction band. On t h e o t h e r hand, t h e l e v e l o f @ - d i s l o c a t i o n i s i n t h e energy gap. The l e v e l 0.7 eV below t h e con- d u c t i o n band, which was found by e l e c t r i c a l conduc- t i v i t y measurements i n deformed GaAs /17/, i s consi- dered t o be associated w i t h 6 - d i s l o c a t i o n .
Recent observations w i t h e l e c t r o n microscope have shown t h a t d i s l o c a t i o n s d i s s o c i a t e i n 111-V com- pounds, too. Three types o f d i s l o c a t i o n s d i s s o c i a t e as follows :
a - d i s l o c a t i o n = 30" a - p a r t i a l
+
90' p a r t i a l,
@ - d i s l o c a t i o n = 30" 6 - p a r t i a l
+
90' p a r t i a l , screw d i s l o c a t i o n = 30" a-+
30" 8- p a r t i a l . From t h e above described v e l o c i t i e s , we may conclude t h a t the v e l o c i t y o f 30" 6 - p a r t i a l d i s l o c a t i o n i s t h e slowest i n InSb and i n n-type GaAs.The author wishes t o thank Dr. g. Mihara, Dr.
S. K. Choi, Mr. H. Nakata and P r o f . H. Suzuki f o r h e l p f u l discussions.
References
/1/ Yihara, Y. and Ninomiya, T., J. Phys. Soc. Jpn., 25 (1968) 1198.
/2/ Osipyan, Yu. A. and Erofeeva, S.A., Sov. Phys.
Sol i d S t a t e ,
-
11 (1969) 770./3/ S t e i n h a r t , H. and Schgfer, S., Acta m e t a l l . ,
g
(1971) 65.
/4/ Erofeeva, S.A. and Osipyan, Yu. A., Sov. Phys.
S o l i d S t a t e , - 15 (1973) 538.
/5/ Erofeeva, S.A. and Osipyan, Yu. A., Sov. Phys.
S o l i d State,
-
16 (1975) 2076./6/ Nihara, ?I. and Ninomiya, T., Phys. Status S o l i d i ( a ) ,
32
(1975) 43./7/ Choi, S.K. and Vihara, Y . , J. Phys. Soc. Jpn., 32 (1972) 1154.
-
/8/ Osvenskii
,
V.B. and Kholodnyi,
L.P., Sov. Phys.S o l i d State, 14 (1973) 2822. -
/9/ Osvenskii, V.B., Kholodnyi
,
L.P. and Y i l v i d s k i i , M.G., Sov. Phys. S o l i d S t a t e ,15
(1973) 661.1101 S t e i n h a r d t , H., quoted i n
16.
/11/ Choi, S.K., Mihara, M. and Ninomiya, T., Jpn.
J. Appl
.
Phys., 16
(1977) 737./12/ Choi, S.K., Thesis, Univ. of Tokyo (1973), quoted i n Yihara, M. and Ninomiya, T., Oyo B u t s u r i ,
47
(1978) 847.
/13/ Choi, S.K., Yihara, M. and Ninomiya, T., Jpn.
J. Appl
.
Phys., 17
(1978) 329./14/ M g l l e r , H. -J., Acta m e t a l l . , (1978) 963.
1151 Ohori, K. and Sumino, K., Phys. Status S o l i d i ( a ) , 21 (1974) 217. -
/16/ Haasen, P,, Phys. Status S o l i d i (a), 28 (1975) - 145.
/17/ Nakata, H. and Ninomiya, T., J. Phys. Soc. Jpn., 42 (1977) 552.
