SIMOX SOI surface smoothing for gate oxide integrity and reliability

A significant reliability aspect regarding commercial application of SOI is the consistency of the device gate oxide integrity (GOI). This research focuses on the smoothing of SIMOX SOI surfaces for advanced CMOS applications with improved GOI and reliability. As shown in an atomic force microscope (AFM) image, as-received samples of full dose single-implant SIMOX annealed in an Ar ambient show a distinct [100] tiling with a measured peak-to-valley surface roughness ranging from /spl sim/55 /spl Aring/ to /spl sim/70 /spl Aring/. These [100] faceted surface features result from silicon surface bond reconstruction during the 1310/spl deg/C SIMOX anneal temperature into their lowest free energy configuration. For the specific samples examined, the facets were typically 0.5 /spl mu/m in diameter with a mean deviation R(a) of 7.1 /spl Aring/ and R(rms) at 8.9 /spl Aring/. In order to reduce the faceting features as well as the surface roughness, a gas cluster ion beam (GCIB) method of surface smoothing was applied to the full dose single implant SIMOX samples.