High-quality surface passivation of silicon using native oxide and silicon nitride layers

Abstract

We report on the attainment of high quality surface passivation of crystalline silicon using facile native oxide and plasma enhanced chemical vapour deposition SiNx. Using systematic measurements of excess carrier density dependent minority carrier lifetime, it is observed that the inferred interface defect density decreases with increasing native oxide thickness while the interface charge density remains unchanged with thickness, which ranges from 0.2 Å to 10 Å. A surface recombination velocity of 8 cm/s is attained corresponding to a native oxide layer thickness of ∼10 Å. Similar chemically grown oxide layer followed by SiNx deposition is shown to yield comparable passivation, indicating practical viability of the passivation scheme.