Back to results
US 6,376,285 B1Granted
Annealed porous silicon with epitaxial layer for SOI
AssigneeTexas Instruments Incorporated
InventorsKeith A. Joyner, Leland S. Swanson
Life of this patent
Estimating the term…
Abstract
An epitaxial layer of silicon is grown on a layer of partially-oxidized porous silicon, then covered by a capping layer which provides structural support and prevents oxidation of the epitaxial layer. A high-temperature anneal allows the partially oxidized silicon layer to separate into distinct layers of silicon and SiO2, producing a buried oxide layer. This method provides a low cost means of producing silicon-on-insulator (SOI) wafers.
Claims8
A method of forming a silicon-on-insulator substrate, comprising the steps of:
- (a.) anodically oxidizing a silicon wafer to produce a layer of porous silicon;
- (b.) partially oxidizing said layer of porous silicon to form silicon oxide on surfaces of pores in the layer of porous silicon;
- (c.) growing an epitaxial layer of silicon on said partially oxidized layer of porous silicon;
- and
- (d.) annealing said wafer to form a continuous buried oxide from the silicon oxide in the layer of porous silicon, with substantially smooth interfaces.
2 more elements
A fabrication method, comprising the steps of:
- (a.) anodically oxidizing a silicon wafer to produce a layer of porous silicon;
- (b.) partially oxidizing said layer of porous silicon;
- (c.) etching said partially oxidized layer of porous silicon to remove the oxide of step (b.) from the top surface of said porous silicon;
- (d.) growing an epitaxial layer of silicon on said partially oxidized layer of porous silicon;
- (e.) covering said epitaxial layer with a capping layer which prevents oxidation of said epitaxial layer;
- (f.) annealing said wafer to allow said partially oxidized layer of porous silicon to separate into distinct layers which include a buried oxide layer;
- (g.) forming transistor structures in said epitaxial layer of silicon;
- whereby said buried oxide layer provides insulation for said transistor structures.
5 more elements
Dependencies are inferred from the claim text.