ULSI-quality gate oxide on thin-film-silicon-on-insulator

Abstract

Gate oxide quality for s u b -0 . 5~ applications on 7hin-FilmSilicon-On-Znsulator (TFSOI) substrates is described.Intrinsic thermal oxide properties such as I-V, QBD and charge trapping rates, as well as device effective mobilities, of TFSOI are comparable to bulk. However, increased surface mim-roughness on SO1 materials leads to a higher thermal oxide defect density relative to that of bulk silicon. The use of wafer polish or stacked thermal/LPCVD oxide is found to be effective in achieving bulk-quality oxide defect densities on TFSOI while maintaining intrinsic I-V, QBD and charge trapping properties.

Evaluation of thermal oxide of SOI layers by the SPE method

“…As to the SIMOX substrate, there are reports on the electrical properties of the oxide film [5,6]. The electric field-electric current density characteristics, the electrical breakdown voltage distribution, and the TDDB characteristics are examined.…”

Optimized Process Conditions for High Quality Gate Oxides on SIMOX SOI Substrates

“…1,2 Higher early failure rate (EFR) of gate oxides grown on silicon-on-insulator (SOI) substrates measured using charge-to-breakdown (Q bd ) and field-induced breakdown, has been reported. 5,6 Quality of gate oxides grown on SOI substrates is known to be sensitive to the fabrication process. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] Imperfections in starting material that may affect the oxide quality include dislocations, stacking faults, metal impurities in SOI film, surface roughness, and trapped charge.…”

“…5,6 Quality of gate oxides grown on SOI substrates is known to be sensitive to the fabrication process. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] Imperfections in starting material that may affect the oxide quality include dislocations, stacking faults, metal impurities in SOI film, surface roughness, and trapped charge. [6][7][8][9][10][11][12][13][14][15] It has also been reported that the damage due to source/drain implantation 16 and stress due to local oxidation of silicon (LOCOS) isolation 17,18 could cause early failure of the thin gate oxide grown on the SOI substrate.…”