HAL Id: jpa-00223089
https://hal.archives-ouvertes.fr/jpa-00223089
Submitted on 1 Jan 1983
HAL is a multi-disciplinary open access
archive for the deposit and dissemination of
sci-entific research documents, whether they are
pub-lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d’enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.
STUDY OF SOME OPTICAL AND ELECTRICAL
PROPERTIES OF HEAVILY DOPED SILICON
LAYERS
A. Slaoui, E. Fogarassy, J. Muller, P. Siffert
To cite this version:
A. Slaoui, E. Fogarassy, J. Muller, P. Siffert.
STUDY OF SOME OPTICAL AND
ELEC-TRICAL PROPERTIES OF HEAVILY DOPED SILICON LAYERS. Laser-Solid Interactions
and Transient Thermal Processing of Materials, 1983, Strasbourg, France.
pp.C5-65-C5-71,
JOURNAL DE PHYSIQUE
Colloque C5, supplkment au nO1O, Tome 44, octobre 1983 page C5-65
STUDY OF SOME OPTICAL AND ELECTRICAL PROPERTIES OF HEAVILY DOPED S I L I C O N LAYERS
A. Slaoui, E. Fogarassy, J.C. Muller and P. Siffert
Centre de Recherches Nucllaires, Laboratoire PHASE, 67037 Strasbourg Cedex,
France
Resume
-
On e t u d i e c e r t a i n e s p r o p r i e t e s optiques de couches de s i l i c i u m dopees au-dela de l a s o l u b i l i t 6 maximale 1 l ' e q u i l i b r e p a r un procede d ' i m - p l a n t a t i o n s u i v i d'une f u s i o n l a s e r .Des p l a q u e t t e s de s i l i c i u m de type P sont implantees 1 des doses a l l a n t j u s q u t l 1017 cmm3 par des i o n s a r s e n i c (80 KeV), puis l e s dopants s o n t incorpores au reseau p a r une f u s i o n l a s e r i n d u i t e par un l a s e r pulse au
-
YAG 1 des energies a l l a n t j u s q u ' 1 2,5 ~ / c m ~ pour des durees d ' i m p u l s i o n s de 25 e t 100 ns, respectivement.La r e f l e c t i v i t e des couches e n t r e 250 e t 500 nm a i n s i que des mesures e l l i p s o m 6 t r i q u e s o n t
e t e
e f f e c t u e e s en f o n c t i o n des c o n d i t i o n s experimen- t a l e s . Aux f o r t e s doses l e s d e f a u t s j o u e n t un r61e non n 6 g l i g e a b l e s u r ces p r o p r i e t e s optiques.A b s t r a c t
-
I t i s w e l l known t h a t t h e s o l u b i l i t y o f most dopants can be n o t i - c e a b l y n c r e a s e d i n s i l i c o n by pulsed l a s e r annealing o f t h e imp1 antedl a y e r s . Here, we have i n v e s t i g a t e d the e v o l u t i o n o f some o p t i c a l and e l e c - t r i c a l p r o p e r t i e s o f such h e a v i l y doped l a y e r s as a f u n c t i o n o f implanted dose, t r y i n g t o separate e f f e c t s due t o t h e h i g h doping from those r e s u l t i n g from d e f e c t s o r p r e c i p i t a t e s
.
P-type s i l i c o n wafers have been implanted w i t h 80 KeV a r s e n i c ions a t doses
- -
-
o f up t o 10'' cm-' and annealed by a pulsed ruby and YAG l a s e r , g i v i n g pulses o f 20 and 100 ns d u r a t i o n , r e s p e c t i v e l y and d e p o s i t i n g energies up t oU.V. and v i s i b l e l i g h t (250 and 500 nm) r e f l e c t a n c e , as w e l l as e l l i p s o m e t r y (632.8 nm) measurements have been performed as w e l l as dark I
-
V and C-
Vc h a r a c t e r i s t i c s .
These i n v e s t i g a t i o n s i n d i c a t e t h a t by i n c r e a s i n g t h e implanted dose, t h e doping l e v e l f i r s t increases u n t i l near s u r f a c e d e f e c t s and p r e c i p i t a t e s modify t h e o p t i c a l as w e l l as t h e e l e c t r i c a l p r o p e r t i e s o f t h e h e a v i l y doped l a y e r s . The generation o f these d e f e c t s has been f o l l o w e d by RBS i n random and c h a n n e l l i n g c o n d i t i o n s .
INTRODUCTION
I n t h e f a b r i c a t i o n o f s o p h i s t i c a t e d devices such as t h e b i p o l a r r a n s i s t o r used i n
$
modern s i l i c o n i n t e g r a t e d c i r c u i t s , i n t e g r a t e d i n j e c t i o n l o g i c ( I L ) and s o l a r c e l l s , t h e use o f h i g h-
dose i o n-
implanted l a s e r-
annealed s i n g l e-
c r y s t a l s i l i c o n allowed ( 1 ) f o r m a t i o n o f b o t h h i g h l y doped shallow'
N
and P+ l a y e r s .C5-66 JOURNAL DE PHYSIQUE
A h i g h
-
power l a s e r i r r a d i a t i o n can anneal t h e i o n-
implanted damage r e g i o n i n s i n g l e-
c r y s t a l semi-conductors. Rapid s u r f a c e m e l t i n g and subsequent l i q u i d phast e p i t a x i a l regrowth i n nanosecond pulse annealing make i t p o s s i b l e t o dope s i l i c o n w i t h e l e c t r i c a l l y a c t i v e i m p u r i t i e s we1 1 above t h e thermal equi 1 ib r i u m s o l i d s o l u - b i l i t y l i m i t (2), and t o completely anneal implanted regions w i t h o u t any macrosco- p i c a l l y extented defects, such as d i s l o c a t i o n s , s t a c k i n g f a c e t s o r p r e c i p i t a t i o n s( 3 ) . Three techniques are used t o analyze e l e c t r i c a l and s t r u c t u r a l p r o p e r t i e s o f l a s e r
-
annealed damage : e l e c t r o n microscopy, He+ b a c k s c a t t e r i n g ( 3 ) and o p t i c a spectroscopy (4,5) m a i n l y i n t h e UV and v i s i b l e range. Indeed, f o r photon energies s m a l l e r than Eo, t h a t i s f o r edge absorption, t h e semi-conductor i s more o r l e s s t r a n s p a r e n t ( f r e e absorption); f o r energies l a r g e r than Eo, i t i s opaque (band t o band absorption). The former gives i n f o r m a t i o n about various l a t t i c e imperfec- t i o n (e.g. i m p u r i t i e s , defects, phonons, e t c....
The l a t t e r i s m a i n l y r e l a t e d t o t h e band s t r u c t u r e and c o n t r i b u t e s e s s e n t i a l l y t o a d e t a i l e d understanding o f the e l e c t r o n i c s t r u c t u r e o f t h e semi-conductor (6). Pankove ( 7 ) has s t u d i e d e x t e n s i v e l y t h e o p t i c a l p r o p e r t i e s o f h e a v i l y doped germanium and has shown t h e m o d i f i c a t i o n i n band s t r u c t u r e and i t s consequence on e l e c t r i c a l p r o p e r t i e s o f P-
N j u n c t i o n s .I n t h i s paper, we attempt t o c h a r a c t e r i z e h e a v i l y doped s i l i c o n l a y e r s by UV and v i s i b l e r e f l e c t i v i t y experiments and by e l e c t r i c a l measurements f o r v e r y l a r g e doping concentrations.
EXPERIMENTS
Several P-type (100) S i wafers, o f 1
-
5 R.cm r e s i s t i v i t i e s , were implanted w i t hAS' (80 KeV) i o n s . The doses ranged between 1015 and 1017 cm-'. This
o p e r a t i o n was f o l l o w e d by Q
-
switched p u l s e YAG o r r u b y l a s e r treatment. The parameters o f t h e l a s e r s a r e r e s p e c t i v e l y : X = 0.532 and 0.690 nm, d u r a t i o n time = 100 and 20 ns, pulse energy = 2.5 and 1.4 ~ / c m 2 . A f t e r l a s e r annealing, almost a l l implanted i m p u r i t i e s were l o c a t e d i n s u b s t i t u t i o n a l p o s i t i o n s , as confirmed by RBS. The maximum c a r r i e r concentrations i n t h e c r y s t a l s were between 8 x 2 0 ' ~ and 4.3 x 10" ( F i g . 1, Table 1) f o r an implanted dose o f 1016 t o 5 x 1 0 l 6 cm-2.F i g . 1
-
RBS spectra f o r both S i and As Table 1-
The samples a r e annealed by a f t e r l a s e r annealing. The ma- l a s e r YAG ( A = 0.53 um) a tThe o p t i c a l r e f l e c t i v i t y spectra were performed o by u s i n g a Beckmann double beam spectrophotometer over t h e range 2500
-
5000A.
An evaporated aluminium m i r r o r , whose r e f l e c t a n c e was assumed t o be 108%. provided t h e reference spectrum. The e l l i p s o m e t r y measurements a t X = 6328 A (He-
Ne) were performed on YAG annealed m-p l e s a t doses 1016 t o 5 x 1016 ~ m - ~ . J u s t p r i o r t o b o t h types o f measurements above the samples were cleaned by f l u o r i d r i c s o l u t i o n t o remove any oxide l a y e r . For e l e c t r i c a l measurements, t h e f r o n t c o n t a c t was r e a l i z e d w i t h Ag evaporation on small nesas and back c o n t a c t was performed w i t h evaporated gold. The s h e e t - r e s i s - tance data was measured w i t h a f o u r
-
p o i n t probe.RESULTS AND DISCUSSION
1 ) OPTICAL CHARACTERISTICS
The r e f l e c t i v i t y sjjectra o f s;bstrate c r y s t a l Two peaks a t 3650 A and 2750 A are observed, and denoted El, E2 r e s p e c t i v e l y . The El
(3.4 ev) peak, i n i t i a l l y a t t r i b u t e d t o an i n t e r b a n d t r a n s i t i o n
ri5
-
r15,
has been revealed (8) t o be a m i x t u r e o fT'
27
:
y12;L i
-
L1 and-
t r a n s i t i o n s F'ig.
As t o the E3 peak (4.5 ev), i t i s due t o t h e a c c i d e n t a l degeneracy o f an M1 edge due t o the X4-
X1 t r a n s i t i o n and an M2 edge due t o t h e C 4-
x1 t r a n s i t i o n (8) ( F i g . 3). Both peaks were p r a t i c a l l y unaf- f e c t e d when t h e doping dose was l e s s than 1016 cm-2 ( F i g . 3 ) . However, t h e peaks were appreciably degraded as t h e dopingc o n c e n t r a t i o n increased. A t 1017 ~s+/cm' t h e E2 peak n e a r l y desappears. We i n t r o - duce t h e r e f l e c t i v i t y change AR, d e f i n e d as t h e d e v i a t i o n from the c r y s t a l l i n e s u b s t r a t e r e f l e c t i v i t y a t 2750
2\
t o b e t t e r d i s t i n g u i s h t h e change w i t h doping. As p r e v i o u s l y i m p l i e d , R s t a r t s t o increase when dose exceeds 1016 cmu2 ( F i g . 4). T h i s k i n d o f behaviour has been a l r e a d y r e p o r t e d f o r P and As implanted and r u b y l a s e r annealed s i l i c o n ( 9 ) . As has been shown ( 9 ) , t h e cause o f t h e degradation o f t h e E2 peak i s n e i t h e r due t o f r e e c a r r i e r s n o r t o s t r e s s caused by i m p u r i t y atoms, b u t r a t h e r t o supersaturated s o l i d s o l u t i o n s o f a r s e n i c i n t h e s i l i c o n l a t t i c e . It i s c l e a r t h a t t h i s r e f l e c t i v i t y reduc- t i o n i s r e l a t e d t o t h e change i n band s t r u c t u r e due t o the h i g h doping.and doped s i l i c o n a r e shown i n F i g . 2.
r
Ee Y A G . LASER1
JOURNAL DE PHYSIQUE 5 El6 cm2 L : Y a g L a s e r T : Therrn.Annea1 (600 a . 30rnn)
-.,
... ,,~.
.. \ , ,.
....
.. - . L+T...
..
'.. ..>..;..
....,, '- ..._ ...I---.
25 &e-
90 20-
80 iR-
>+
15 I-., > 70 C-( a c a 10 0 W 60 52
W 50 05
LO *2
w w 40 d -74 * 0 0 0 0 0 0 DOSE (crn-2) I~ ~ mO Um J o O v~ Om O A (nrnlFig. 4
-
The r e f l e c t i v i t y change AR (devia- Fin. 5-
Optical r e f l e c t i v i t y tion from the,crystal Si r e f l e c t i - spectra f o r c r y s t a l l i n e vity a t 2750 A ) versus implanted ( - ) and dopeddose. ( 4 . 5 2 lo2' cmU3) ~ i . L designates l a s e r annea- 2 ling (2.5 J/cm ) and T thermal annealing (600° C, 20
mn)
16 2In Fig. 5 shows r e f l e c t i v i t y spectra f o r 5
x
10 /cm doping dose before and a f t e r thermal annealing (600" C , 20 mn). After l a s e r annealing, the highly substitutional arsenic concentration i n s i l i c o n i s metastable. Thermal annealing increases the fraction of i n t e r s t i t i a l atoms and consequently the number of active atoms decreases, as seen by sheet r e s i s t i v i t y measurements. There r e s u l t s , as observed in Fig. 5, the increase of theE2
peak. We can conclude t h a t the r e f l e c t i v i t y reduction i s mainly due to high doping level. Similar behaviour i s observed f o r ruby l a s e r an-,
11 ? 3 6r:
8 M8
3 5,
3 4 nealed samples. 3 15 Several reports in the l i t e r a t u r e (10, 11) inves- Ptigated the e f f e c t s of l a s e r annealing on ion im-
3
planted s i l i c o n layers by using ellipsometry *-
which i s a f a s t and non-destructive method t ocharacterize c r y s t a l damage. From e l 1 ipsometri c
"
,,
measurements, i s i s possible t o calculate refrac- 5
t i v e and extinction indices and absorption coef- f i c i e n t s . Changes i n optical constants can be
k
a t t r i b u t e d t o transformation of the Si band s t r u c - E t u r e a f t e r implantation and annealing.E
=
Fig. 6 shows the r e f r a c t i v e index and absorption
k
c o e f f i c i e n t as a function of implanted dose. The former decreases with increasing dose and satura- tion a t 4x
1016 cmm2, but the second r i s e s t o0
value nearly on order of magnitude higher than
the one f o r pure s i l i c o n . Ostaja e t a7. ( 5 ) fmiP
suggest t h a t the very highly doped layers are F i g . 6
-
Absorptioncoefficient
responsible f o r t h i s increase of the absorption-
and refraction index AS+ c o e f f i c i e n t , giving low diffusion lenghts.F i g . 7
-
Sheet r e s i s t i v i t y versus implanted F i g . 8 - Dark forward and reverse I - V dose. The p u l s e energy f o r YAGand ruby l a y e r s are 2.5 and 1.4 c h a r a c t e r i s t i c s 1=1 (*-1) s nkT J/crn2 r e s p e c t i v e l y . The values
c a l c u l a t e d
t
. - ) gives good agree- where Is i s t h e s a t u r a t i o n ment w i t h experiment (... and--- ) . c u r r e n t , n the qua1 i t y f a c t o rIf is t h e reverse leakage c u r r e n t .
2) ELECTRICAL CHARACTERISTICS
The e l e c t r i c a l a c t i v i t y o f t h e implanted a r s e n i c atoms was proved by sheet r e s i s t a n - ce measurements as shown i n F i g . 7. We observe, f o r YAG and ruby l a s e r treatments, a decrease of R as the dose increases from 1015 t o 5 x 1016 cm-2, f o l l o w e d by an increase f o r doses between 5 x 1016 and 1017 cm-'. The p o s s i b i l i t y was considered t h a t the l a s e r energy d e n s i t y was n o t s u f f i c i e n t t o anneal and a c t i v a t e a l l dopants
2
a t 1017 ~ s + / c m and t h a t p r e c i p i t a t i o n has taken p l a c e due t o the As s o l u b i l i t y 1 i-
m i t ( 6 x
loz1
~ m - ~ ) (12) a f t e r annealing. On t h e same f i g u r e , two o t h e r curves are p l o t t e d : t h e f i r s t ( s o l i d l i n e ) i s t h e Smith e t a l . curve (13) f o r d e v i a t i o nIS S = 250 which has been e x t r a p o l a t e d t o a dose h i g h e r than 1016 ~ r n - ~ . The second curve was d e r i v e d from t h e equation R = (qNs u ) - I where Ns corresponds t o t h e t o t a l number of implanted i o n s per u n i t surface are, and i s the e l e c t r o n m o b i l i t y given by H i l l (14) f o r c a r r i e r c o n c e n t r a t i o n C between
lo2'
and cmb3.P = 7.5 x 10"
c - l l 2 ;
Ns and C were determined by RBS f o r each dose. C a l c u l a t e d va- l u e s were found t o be i n good agreement. For doses i n excess o f 5 x 1015 ~ m - ~ , R (YAG) i s lower than R ( r u b y ) because t h e j u n c t i o n i s deeper f o r t h e YAG l a s e r i r - r a d i a t i o n . This i s due t o t h e d i f f e r e n c e i n t h e p u l s e d u r a t i o n o f YAG ( T = 100 ns) and ruby ( T = 20 ns) l a s e r s i n which t h e l o n g e r p u l s e i n d i c e s a t h i c k e r m e l t i n g zone. The values found are much low ( 2 10/SQ), i m p l y i n g a very good e l e c t r i c a l a c t i v a t i o nWe r e p o r t i n Fig. 8, t h e dark forward and reverse c u r r e n t - v o l t a g e c h a r a c t e r i s t i c s o f t h e l a s e r annealed j u n c t i o n s and o f the thermal d i f f u s e d diode. The forward c u r r e n t recombination f a c t o r nr as d e f i n e d by J = Jor lexp (qV/nrkT)
-
11 was c a l c u l a t e d over the range 0 t o 0.35 v o l t s . Contrary t o d i f f u s e d j u n c t i o n s , t h e devices annea- l e d by YAG o r ruby l a s e r s e x h i b i t e d recombination f a c t o r i n t h e range 1.6 t o 4.2 i m p l y i n g t h e existence of a l a r g e r space charge r e g i o n and surface c o n c e n t r a t i o n of d e f e c t s t h a t a c t as generation-
recombination centers (Table 11). These h i g h va- lues of nr ( > 2) are n o t p r e d i c t e d by t h e Sah-
Noyce and Shockley ( S-
N-
S) theo-C5-70 JOURNAL DE PHYSIQUE
r y ( 1 5 ) , b u t c o u l d be due i n p a r t t o shunt r e s i s t a n c e e f f e c t s and i n p a r t t o m o d i f i - c a t i o n s i n t h e S - N - S theory which account f o r n o n - u n i f o r m i t i e s i n t h e d i s t r i b u - t i o n o f recombination centers ( 1 6 ) . The h i g h l e v e l o f doping makes f o r d i f f u s i o n
Id and recombination Ir s a t u r a t i o n c u r r e n t s t h a t are more than one o r d e r o f magnitu- de h i g h e r than those o f d i f f u s e d diodes, suggesting a change i n d i f f u s i o n constant D, d i f f u s i o n l e n g h t L and i n t r i n s i c c o n c e n t r a t i o n ni composing t h e s a t u r a t i o n c u r r e n t . For h e a v i l y doped l a y e r s , ni i s remplaced by an e f f e c t i v e i n t r i n s i c c o n c e n t r a t i o n
n such t h a t
A
Egi e n i e = n exp
i
(-n)
where A Eg i s t h e shrinkage band gap ( 1 7 ) . Another e l e c t r i c a l c h a r a c t e r i s t i c i s t h e leakage, o r reverse, c u r r e n t ,which we take as Va =
-
1 v o l t . The reverse leakage c u r r e n t ,If,
i s due t o t h r e e mechanisms : c a r r i e r d i f f u s i o n , generation o f c a r r i e r s w i t h i n the d e p l e t i o n regions, and generation o f c a r r i e r s due t o the i n t r o d u c t i o n o f recombination centers a t t h e surface o f t h e p-n j u n c t i o n s . This t h i r d mechanism i s p r e v a l e n t and l a r g e l y exceeds t h e importance o f the o t h e r two (18). As f o r t h e recombination q u a l i t y f a c t o r nr, the increase o f t h e reverse c u r r e n t i n implanted and l a s e r annealed j u n c t i o n s can be due t o surface, and space charge induced defects. Since we have observed s i m i l a r behaviour f o r l a s e r annealed d i f f u s e d j u n c t i o n s (19), we suggest t h a t t h e p r o p e r t i e s o f t h e surface a f t e r l a s e r treatment ( h i g h doping l e v e l , dan- gling-bands, h i g h absorption c o e f f i c i e n t , recombination v e l o c i t y , e t c ...) are m a i n l y r e s p o n s i b l e o f t h e h i g h measured reverse c u r r e n t .Table I 1
-
We assumes,,
I = IoD(expA-
-
n,kT 1)
Table I11
-
$ ( Y ) and $ designate d i f f u - s i o n ~ o t e n t i a l f o r YAG and DOSE lel6cn? O ( Y ) (V) O ( R ) (V)ruby annealed 1 ayers respec- 9 "
+ loR(ex~
-
'1)where K i s a constant depending upon t h e doping c o n c e n t r a t i o n on the p and n sides o f t h e j u n c t i o n , and n i s a constant normally l y i n g between 2 and 3, and i s a measure of the doping p r o f i l e . Here, we found n = 3 i m p l y i n g a l i n e a r l y graded j u n c t i o n . From these measurements, we deduce t h e d i f f u s i o n p o t e n t i a l e
+
presented i n Table 11. The values o f implanted l a s e r annealed j u n c t i o n s are v e r y much lower than those o f d i f f u s e d diodes (0.9 v o l t ) . This d i f f e r e n c e suggest the possi- b i l i t y o f compensating d e f e c t s i n t h e j u n c t i o n r e g i o n (20). As t h e d i f f u s i o n po- t e n t i a l i s d i r e c t l y r e l a t e d t o t h e energy band gap o f t h e semi-conductor, and the @ a r e low, these r e s u l t s c o u l d i n d i c a t e a shrinkage of the energy gap (7) due t o t h e h i g h doping 1 eve1.
CONCLUSION
We have s t u d i e d t h e e l e c t r i c a l and o p t i c a l c h a r a c t e r i s t i c s o f i o n implanted l a s e r annealed s i l i c o n . I n p a r t i c u l a r , t h e decrease o f t h e r e f l e c t i v i t y and t h e i n c r e a - se o f the a b s o r p t i o n c o e f f i c i e n t can be r e l a t e d t o t h e degree o f s u p e r s a t u r a t i o n o f t h e s o l i d s o l u t i o n which r e s u l t s from t h e very h i g h doping l e v e l . There r e s u l t s degraded e l e c t r i c a l c h a r a c t e r i s t i c s ( h i g h recombination q u a l i t y f a c t o r , h i g h satu- r a t i o n and reverse c u r r e n t s ) which c o u l d l i m i t t h e performance o f t h e devices.
REFERENCES
1. SHTYRKOV G . I . , KHIBULLIN I.B., GALYATUDINOV M.F. and BAYAZITOV R.M. Sov. Phys. Semicond.
2
(1975) 1309.2 . LEITOLA A. and GIBBONS J.F.. Appl. Phys. L e t t e r s
35
(1979) 532.3. NATSUAKI N., TAMURA M. and TOKUYAMAT T.. J. Appl. Phys. 5 1 (1980) 3373. 4. McGILL T.C., KURTIN S.L. and SHIFRIN G.A.. J . Appl. Phys.74 (1970) 246. 5. OSTOJA P., SOLMI
s.,
ZANI A.. J. ~ p p i . P ~ Y S . 52 (1981) 62m.6. TAUC J.C.. "Progress i n Semiconductors" Vol. 9 7 ~ i b s o n and Burgess eds, T e m ~ l e books. L t d London. 1965) , D .
.
88.PANKOVE J.I.: I b i d , p. 48.
GREENAWAY D.L. and HARBEKE G.. " O p t i c a l p r o p e r t i e s and band s t r u c t u r e o f semi- conductors" (ed. by PAMPLIN B.R., Pergamon Press, 1968).
MOTOOKA T., MIYAO M. and TOKUYAMA T.. J. Electrochem. Soc. Montreal (1982) WATANABE K., MOTOOKA T., HSHIMOTO N. and TOKUYANA T.. Appl. Phys. L e t t e r s 36 (1980) 451.
-
NAKAMURA K., KAMOSHIDA M., VEHARA A. and TATSUMI R.. "AIP Proceedings No 50 on l a s e r i n t e r a c t i o n and l a s e r processing m a t e r i a l s research S o c i e t y Meeting"
(Ed. by FERRIS F.D., LEAMY M.J. and POATE J.M., Boston, 1979) p. 434.
FOGARASSY E
.
,
STUCK E.
,
GROB A. and SIFFERT P. .
"Laser and e l e c t r o n beam pro- cessing o f m a t e r i a l s ' ' (WHITE C.W. and PEERCY P.S. eds, Academic Press, New York, 1980) p. 117.SMITH B.J. and STEPHEN J.. Rad. E f f . 14 (1974) 181.
HILL C.. "Laser Annealing o f SemicondiFtor". (Ed. by POATE J.M. and MAYER J.W., Academic Press, New York, 1982) p. 511.
SAH C.T., NOYCE R.N. and SHOCKLEY W.. Proc. IRE 45 (1957) 1228.
HOVEL H .J
..
"Semiconductors and Semimetal s ",
Vol.11, Sdar C e l l s (Ed. by WILLARDSON R.K. and BEER A.C., Academic Press, New York, 1975).MERTENS R.P., VAN MEERBERGEN J.L., NIJS J.F. and VAN OVERSTRAETEN R.J., IEEE Trans. E l e c t r o n . Devices, Vol. Ed
27
(1980) 949.BORDFFKA H., KRIMMEL E.F., LINDER M. and RUNGE H.. "Laser and E l e c t r o n beam processing o f e l e c t r o n i c m a t e r i a l s " , Ref. 12, p. 178.
SLAOUI A.. Rapport de DEA "Etude du processus de recombinaison dans l e s c e l l u - l e s s o l a i r e s m o n o c r i s t a l l i n e s par l e s c a r a c t e r i s t i q u e s I - V d ' o b s c u r i t & " , (Centre de Recherches Nucleaires de STRASBOURG, 1982).
