Observation of two coupled defect levels on the hydrogen-passivated Si (1 0 0) surface

Abstract

We present the first electronic characterization of intrinsic defects on the hydrogen-passivated silicon surface. Surface recombination velocities, measured with radio-frequency photoconductance decay, show that lifetimes of both n- and p-type wafers change significantly with small changes in the background carrier concentration ( η≡Δ n/ p 0≈0.05). These effects are not explained by the Shockley-Read-Hall model for single-level defect recombination but can be understood by modeling the defect as a coupled, two-level (three charge state) system. By analogy with the P b-center, these defects may be thought of as dangling bonds populated with zero, one, or two electrons.