プロトン剥離現象における不純物依存性

Abstract

Silicon wafers implanted at adequate conditions (such as room temperature, SOkeV, 5 × 10^<16> H-crn^<-2>) induce exfoliation phenomena after 500℃ heating. In this study, for making of the influence of impurity clear, the damaged layer in the hydrogen-implanted silicon was observed with cross sectional transmission electron microscopy. And the exfoliated surface was observed by optical-microscopy and atomic force microscopy (AFM) The behaviors of three types of specimens (p++, p and n type, respectively) were compared by carrying out in furnace annealing. The quantity of defect is proportional to the concentration of dopant, and it is interesting to note that p++ and p type had a sharp peak in the depth profile, but n type had a broad peak and a second peak in a shallow region. The number of exfoliation was proportional to the dopant concentration. So was the total exfoliated area (ratio of area). The other hand, the average area of exfoliation was biggest in n type silicon and was in smallest in p++ type. It seems that the average area was not affected by dopant, while it was affected by the depth of exfoliation.