Process for growing epitaxial silicon in the windows of an oxide-patterned wafer

Abstract

A method of growing epitaxial regions comprising the steps of providing a silicon substrate, forming a patterned oxide layer having a planar upper surface on the substrate, the oxide layer having an aperture therein extending to the substrate, forming a layer of silicon in the aperture extending above the surface of the oxide layer and removing the portion of the layer of silicon extending above the surface of the oxide layer. The sidewalls of the oxide layer defining the aperture are outwardly sloped in the direction of the upper surface. The layer of silicon is formed by a procedure which forms crystalline silicon in the aperture and forms no silicon over the oxide layer. The portion of the layer of silicon extending above the surface of the oxide layer is removed by a chemical-mechanical polishing operation. In addition, to provide auto-alignment, the layer of oxide is selectively etched relative to the layer of silicon to provide a step at the interface of the layer of oxide and the layer of silicon. Then an oxide layer is formed over the layer of oxide and the layer of silicon.

Dependencies are inferred from the claim text.