Effects of the surface oxide layer on platelet growth in H2+-implanted Si

Abstract

The effect of a surface oxide layer on platelet growth in H2+-implanted Si was investigated. Samples of p-type Cz Si (100) and the same Si covered with a 170 nm thick thermal oxide layer were implanted with H2+ ions to a fluence of 2.5 × 1016 H2+/cm2 at room temperature. Post-implantation thermal annealing at temperatures between 773 K and 973 K for 30 min was performed in a flow of N2. Optical microscopy, cross-sectional transmission electron microscopy (XTEM) and micro-Raman spectroscopy were performed to investigate the effect of the oxide layer on platelet evolution upon annealing. Optical microscopy observations show that blisters and half-open blisters occur on the surface of Si with the oxide layer, but craters and half-open blisters occur on the pure Si surface. XTEM observations show that the growth rate of platelets in the defect band of Si with the oxide layer is slower than that in the pure Si sample, due to the lower concentration of vacancy-type defects in the Si with the oxide layer. The density of frank loops increases with increasing annealing temperature in the Si with the oxide layer.