プロトン注入シリコンの加熱その場観察

Abstract

It is known that silicon wafers implanted at adequate conditions (such as room temperature, 80keV, 5×10^ / 16>H・cm-<-2>) induce exfoliation phenomena after 500℃ heating. However, we found that the samples implanted at -150℃ did not induce exfoliation even at above 500℃ heating. In this study, for making of the influence of implantation temperature clear, the damaged layer in the hydrogen-implanted silicon was observed with cross sectional transmission electron microscopy. The behaviors of three types of specimens (implanted at -150℃, at room temperature and at + 100℃, respectively) were compared by carrying out in-situ heating experiment. In the case of -150℃implantation, the defects-distribution became wider. This wider defects-distribution assists the preservation of much hydrogen gas and this phenomenon impedes the exfoliation by suppressing the growing pressure of hydrogen in the sample implanted at -150℃. In the in-situ heating experiments, the quantities of damages showed a tendency to decrease above 300℃. Although, the damages in the sample implanted at -150℃ vanished by heating of around 750℃, the damages of the sample implanted at room temperature tended to vanish at the heating of above 900℃. The damages of the sample implanted at + 100℃ remained even at above 1100℃ heating. These results showed that the recovery temperature of the damage caused by high-dose hydrogen-implantation had the relation with the implantation temperature.