SHALLOW TRENCH ISOLATION FORMATION WITHOUT PLANARIZATION

摘要

Structures for shallow trench isolation regions and methods for forming shallow trench isolation regions. A trench is etched partially through a device layer of a silicon-on-insulator substrate. A section of the device layer at a bottom of the trench is thermally oxidized to form a shallow trench isolation region in the trench. During the thermal oxidation, another region of the device layer may be concurrently oxidized over a partial thickness and, after removal of the oxide from this device layer region, used as a thinned silicon body. Prior to the thermal oxidation process, this device layer region may be implanted with an oxidation-retarding species that decreases its oxidation rate in comparison with the oxidation rate of the section of the device layer used to form the shallow trench isolation region.