Thick elevation of silicon on patterned structure using ion implantation induced selective etching

Selective elevation of silicon on Si/SiO2 patterned structures has been achieved through an implantation mediated selective etching process. 100 nm thick epitaxial silicon/polysilicon layers were formed on patterned structures through conventional chemical vapor deposition (CVD) at 700 deg. C. Selectivity between etching of silicon and polysilicon was achieved by 140 keV 2 x 1014 cm-2 argon implantation in <1 0 0> channeling direction. Etching of implanted layers showed variation along the depth profile. Polysilicon layers were removed by optimizing the etching time in accordance with etch-profiles and the structure-geometry. A short-duration annealing at 420 deg. C was found necessary to enhance selectivity and control over the etching process. Facet free elevation of silicon was achieved under optimized conditions of implantation and etching. The process is not bound by thickness limits, and independent of the pattern material