US 4,532,700 A · Method of manufacturing semiconductor structures having an oxidized porous silicon isolation layer

Abstract

A method is provided for manufacturing semiconductor structures having dielectrically isolated silicon regions on one side of a silicon body. This is accomplished by forming in the silicon body a set of buried regions and a set of surface regions having characteristics which make them anodically etch slower than the remaining portion of the silicon body. These two sets of regions define portions in the silicon body which are anodically etched to form porous silicon regions which are oxidized to form an isolation structure that isolates the silicon surface regions from each other and the remaining portion of the silicon body. Typically in a P-type silicon body the buried and surface regions are N-type regions formed through ion implantation. Using these N-type regions to control the exposure of the P-type material to the anodic etching solution and the formation of the porous silicon regions, a structure is obtained wherein surface monocrystalline silicon regions are isolated from the rest of the silicon body by a uniform layer of silicon dioxide having a predetermined thickness.

Claims15

Dependent claims

A method of forming a semiconductor structure having dielectrically isolated monocrystalline silicon regions comprising:

(a) providing a silicon body of a predetermined conductivity;
(b) forming in said silicon body a set of buried regions which under predetermined anodizing conditions etch slower than the silicon regions adjacent them;
(c) forming a set of surface regions which under said anodizing conditions etch slower than the silicon regions around them wherein said surface regions overlie said regions between adjacent buried regions and partially overlie said adjacent buried regions and wherein said buried regions and said surface regions define a portion in said silicon body which etches faster than said buried and surface regions under said predetermined anodizing conditions;
(d) anodically etching said silicon body to selectively convert said silicon regions between buried regions and surface regions and said silicon portion between said two sets of regions into porous silicon material;
(e) subjecting said silicon body to oxidation to convert said porous silicon material into silicon dioxide.

2 more elements

Dependencies are inferred from the claim text.

Method of manufacturing semiconductor structures having an oxidized porous silicon isolation layer

Life of this patent

Method of manufacturing semiconductor structures having an oxidized porous silicon isolation layer

Life of this patent

Abstract

Claims15