The influence of hydrogenation on the electrical properties of impurity-contaminated silicon grain boundaries

Abstract

In this article, the impact of hydrogenation on the electrical properties of impurity (Fe)-contaminated silicon grain boundaries (GBs) is investigated using capacitance-voltage (C-V) and capacitance transient (C-t) techniques with hybrid orientation direct-silicon-bonded (DSB) wafers. The samples consist of a 2.3 μm thick (110) Si layer on a p-type (100) Si substrate produced via hydrophilic wafer bonding, cleavage, and epithickening. It was found that for a relatively clean GB, the density of the GB states (DGB) is ∼6 × 1012 eV−1cm−2, and the charge neutral level is ∼0.53 eV from the valance band. DGB increases to more than 2 × 1013 eV−1cm−2after the Fe contamination, which is reduced to ∼1 × 1013 eV−1cm−2 after the hydrogenation treatment. The charge neutral level, which shifts toward the conduction band after the Fe contamination, is reversed after hydrogenation. © 2015, The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht.