Hydrogen passivation of deep energy levels at the interfacial grain boundary in (110)/(100) bonded silicon wafers

Abstract

This letter evaluates the density of grain boundary (GB) states before and after hydrogenation by J-V, C-V, and capacitance transient methods using gold/direct silicon-bonded (DSB) (110) thin silicon top layer/(100) silicon substrate junctions. The GB potential energy barrier in thermal equilibrium was reduced by 70 meV from 0.46 eV (before hydrogenation) to 0.39 eV (after hydrogen treatment). Whereas the clean sample had a density of GB states of ∼6×1012 cm−2 eV−1 in the range of Ev+0.54–0.64 eV, hydrogenation reduced the density of GB states to ∼9×1011 cm−2 eV−1 in the range of Ev+0.56–0.61 eV, which is about a sevenfold reduction from that of the clean sample.