Surface roughness improvement of simox substrates by controlling orientation of angle of starting material

Abstract

A method of improving surface morphology of a semiconductor substrate when using an SOI technique comprises providing a silicon ingot positioned on a support member, orientating the silicon ingot in relation to the support member, and a cutting device, and cutting the silicon ingot along about a (100) crystal plane of the silicon ingot, preferably using a wire saw. This then provides a silicon substrate having an initial surface defining a miscut angle which is less than about 0.15 degrees from the (100) crystal plane. The method then comprises processing the silicon substrate using SIMOX processing, which includes implanting oxygen atoms in the silicon substrate to form a buried oxide layer and annealing the silicon substrate to provide a final substrate surface. Finally, the method includes accepting the final substrate surface for further processing when the final substrate surface measures between 2-20 Å RMS using an atomic force microscopy technique.