Annealed porous silicon with epitaxial layer for SOI
First Claim
Patent Images
1. 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.
1 Assignment
0 Petitions
Accused Products
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.
-
Citations
8 Claims
-
1. 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. - View Dependent Claims (2, 3)
-
-
4. 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.- View Dependent Claims (5, 6, 7, 8)
-
Specification