Optical absorption due to H-point defect complexes in quenched Si doped with C

We investigated the point defects, which exist at high temperatures in C-do ped Si. Specimens were prepared from a floating-zone grown Si crystal doped with C (C concentration: 1.7 x 10(17) cm(-3)). They were sealed in quartz capsules together with hydrogen (H) gas, with pressure of 1 or 0.8 atm at h igh temperature, and were annealed at high temperature for Ih followed by q uenching in water. We measured their optical absorption spectra at about 7 K with an FT-IR spectrometer. Several peaks coincided with those observed i n proton-implanted Si. We concluded that H-point defect complexes exist in those specimens. In C-doped Si, VH4 (V: monovacancy) defects are formed by the reaction between VH3 defect and H during quenching or annealing. The fo rmation energy of V obtained in this study is smaller than the calculated o ne in intrinsic Si crystal by more than 1.5 eV. (C) 1999 Elsevier Science B .V. All rights reserved.