DLTS study of oxygen precipitates in silicon annealed

zhangcunbiao

DLTS  study  of oxygen  precipitates  in  silicon  annealed
at  high  pressure
I.V.  Antonova  a'*,  A.  Misiuk  b,  V.P.  Popov  a,  L.I.  Fedina  a,  S.S.  Shaimeev  a
aInstitute  of Semiconductor Physics,  Lavrent  'eva  13,  630090 Novosibirsk,  Russian Federation
blnstitute  of Electron  Technology,  Al.Lotnikow  32/46,  02-668 Warsaw, Poland
Received 9 December 1995;  revised 19 March  1996
Abstract
The  evolution  of  oxygen  precipitates  (OPs)  created  at  900-1000 K  in  Si-Cz  with  initial  oxygen  concentration
8 × 1017 cm  -3  was  studied  by DLTS  technique.  The  samples were  subjected  to  high  pressure  (HP)  treatment  up  to
1.3 GPa  at high  temperature (HT,  1230-1550  K) which caused a partial dissolution  of OP. A new way of studying the
oxygen distribution is suggested.  It is based on the investigation of an electrically active complex of  the oxygen atom with
a  vacancy  (A-center,  level  E  c-  0.18eV).  A-centers  were  introduced  by  3.0MeV  electron  irradiation  with  dose
1 x 10  t5 cm  -2  and  DLTS was  used  for A-center agglomerates detection. The  analysis of data  obtained  allows one  to
conclude that the irradiation dose used does not decompose OPs. It has been found that hydrostatic pressure retards OP
dissolution at HT treatment through a decrease in the migration energy o~a,  coefficient D  O  and diffusion  coefficient D. The
effect  is  explained  on  the  assumption  that  oxygen  diffuses  in  the  form  of  connected  pairs  of  the  oxygen  and  self-
interstitials.