Improvement in gate oxide integrity on thin-film silicon-on-insulator substrates by lateral gettering

Abstract

Lateral gettering is implemented in thin-film silicon-on-insulator (TFSOI) substrates by introducing crystalline defects in the vicinity of metal-oxide-semiconductor device channel regions prior to gate oxidation. As a result of the gettering a significant improvement in gate oxide integrity is achieved, with increased oxide breakdown voltages and charge-to-breakdowns, as well as a reduction in localized oxide charge trapping. The same gettering effect on separation-by-implantation-of-oxygen and bonded silicon-on-insulator substrates suggests that the lack of effective gettering is mainly responsible for the oxide degradation regardless of the TFSOI type. This work also demonstrates the feasibility of achieving bulk-comparable gate oxides on TFSOI substrates.