水素イオン注入により発生したシリコン結晶内プレートレットのTEM観察

Abstract

A damaged layer formed by high dose hydrogen implantation into a silicon wafer has been observed with cross sectional Transmission Electron Microscopy Q(TEM). Hydrogen ions were implanted into n-type (100) silicon at 80keV with a dose of 1.0x10^<17> atoms/cm^2. Four kinds of major defects, i.e., (1)～(4) observed as in the following, are investigated; (1) point-like defects existing broadly between surface and projection range (Rp), (2) (100)platelets existing around the Rp, (3) (111)platelets existing in the deeper region than the Rp, (4) dislocation-like loops in the region deeper than the damaged layer. In the sample with lower implantation dose, i.e., 8.0x10^<16> atoms/cm^2, the dislocation loop was not observed. After 300℃ annealing, cracks were observed at the Rp. After 475℃ annealing, the (111)platelets disappeared. In addition, the depth profile of hydrogen distribution was measured by Secondary lon Mass Spectroscopy (SIMS). Si-H bond condition was investigated by Fourier Transform Infrared spectroscopy (FTIR). Comparing those results with the results obtained by XTEM, it is found that the point defects and platelets contain hydrogen atoms, and (111)platelets involve Si_2-H_6 bond.