Patent ID: 6627484
Filing Date: 2003-09-30
Classification: H01L

Abstract:
A method of forming a semiconductor on insulator structure, the method comprising the steps of:providing a semiconductor on insulator (SOI) substrate including a bulk semiconductor substrate, an insulation layer formed on the bulk semiconductor substrate, and an active layer of semiconductor material formed on the insulation layer; performing a first trench etch by etching a plurality of trenches from a top surface of the active layer only partially through the active layer; performing a second trench etch following the first trench etch by further etching only a subset of the plurality of trenches completely through the active layer to the insulation layer; performing an oxidation step to form oxide on the exposed surfaces of the active layer in the plurality of trenches, including the sides of the trenches etched completely through the active layer and the sides and bottom of the trenches etched only partially through the active layer; performing an anisotropic oxide etch to remove oxide formed at the bottom of trenches etched only partially through the active layer while retaining oxide formed on the sides of the plurality of trenches; and siliciding the bottom of the trenches etched only partially through the active layer to render at least a portion of the active layer conductive to electrically connect regions of the active layer on opposite sides of the trenches etched only partially through the active layer, wherein the oxide formed on the sides of the plurality of trenches prevents silicidation along the sides of the plurality of trenches.