Influence of silicon wafer surface orientation on very thin oxide quality

We studied effects of silicon wafer surface orientation on very thin oxide quality, testing Si(100) and (111) wafers. It has been found that the very thin oxide structure is dominating by the silicon wafer surface orientation, and that when Si(111) is oxidized, SiO2/Si(111) interface microroughness increases as oxide gets thicker than 10 nm, resulting in a degradation of oxide films quality on Si(111). When oxide thickness is decreased to less than 10 nm, SiO2/Si interface smoothness is maintained similar to Si(100) and (111) but the SiO2/Si interface exhibits larger interface charges and larger flatband voltage shift for Si(111) than for Si(100).