Impact of doped microcrystalline silicon oxide layers on crystalline silicon surface passivation

Abstract

This paper reports on a comparative study of the impact of phosphorous and boron doped microcrystalline silicon oxide (μc-SiOx:H) layers on the surface passivation of n- and p-type doped crystalline silicon float zone wafers in correlation with the material properties of the μc-SiOx:H layers. The poor surface passivation of μc-SiOx:H films deposited directly on c-Si surface might be attributed to the incorporation of doping impurities, the surface damaging by ion bombardment and (or) the low amount of hydrogen at the μc-SiOx:H/c-Si interface. The different impact of n- and p-type doped μc-SiOx:H films on the passivation of n- and p-type doped wafers with and without an additional a-SiOx:H passivation layer are correlated to the differences in the strength of the field effect at the heterojunction and to the presence of boron atoms that can cause the rupture of Si–H bonds.