Injection-level dependent surface recombination velocities at the silicon-plasma silicon nitride interface

Abstract

Experimental evidence is presented that the effective surface recombination velocity (Seff) at p-silicon surfaces passivated by silicon nitride films (fabricated in a plasma-enhanced chemical vapor deposition system) shows an injection-level dependence similar to the behavior of thermally oxidized silicon surfaces. Using the microwave-detected photoconductance decay method, injection-level dependent Seff measurements were taken on nitride-passivated p-silicon wafers of different resistivities (1.5–3000 Ω cm). The obtained Seff values also show that for low-resistivity substrates (≤2 Ω cm), nitride passivation is as effective as conventional oxide passivation (and even superior at low injection levels) and furthermore offers the advantage of a less pronounced injection-level dependence.