ELECTRICALLY ISOLATED SiGe FIN FORMATION BY LOCAL OXIDATION
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Accused Products
Abstract
A silicon germanium alloy layer is formed on a semiconductor material layer by epitaxy. An oxygen impermeable layer is formed on the silicon germanium alloy layer. The oxygen impermeable layer and the silicon germanium alloy layer are patterned to form stacks of a silicon germanium alloy fin and an oxygen impermeable cap. A shallow trench isolation structure is formed by deposition, planarization, and recessing or an oxygen permeable dielectric material. An oxygen impermeable spacer is formed around each stack of a silicon germanium alloy fin and an oxygen impermeable cap. A thermal oxidation process is performed to convert a lower portion of each silicon germanium alloy fin into a silicon germanium oxide. During the thermal oxidation process, germanium atoms diffuse into unoxidized portions of the silicon germanium alloy fins to increase the germanium concentration therein.
7 Citations
28 Claims
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1-10. -10. (canceled)
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11. A method of forming a semiconductor structure comprising:
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forming a plurality of vertical stacks on a semiconductor material layer, each of said plurality of vertical stacks including a silicon germanium alloy fin and an oxygen impermeable cap; forming a shallow trench isolation structure laterally surrounding lower portions of said plurality of vertical stacks, said shallow trench isolation structure comprising an oxygen permeable material; forming an oxygen impermeable spacer directly on sidewalls of upper portions of said plurality of vertical stacks; oxidizing an upper portion of said semiconductor material layer and lower portions of each of said plurality of silicon germanium alloy fins employing an oxidation process; and physically exposing sidewall surfaces of remaining portions of said plurality of silicon germanium alloy fins by removing said plurality of oxygen impermeable spacers and said plurality of oxygen impermeable caps. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification