Method of producing simox wafer

Abstract

A SIMOX wafer is produced at an oxygen ion implantation step and a high-temperature annealing step, wherein an oxide film is formed on a surface of a wafer prior to the oxygen ion implantation and then the oxygen ion implantation is conducted through the oxide film.

Description

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a behavior of particles in SIMOX process according to the conventional technique.

FIG. 2 is a schematic view illustrating a behavior of particles in SIMOX process according to the invention.

FIG. 3 is a schematic view illustrating the way of improving a flow of electric charges from a contact pin at an oxygen ion implantation step.

FIG. 4 is a flow chart of a typical SIMOX process according to the invention.

Claims

1. A method of producing a SIMOX wafer comprising an oxygen ion implantation step and a high-temperature annealing step, wherein an oxide film is formed on a surface of a wafer prior to the oxygen ion implantation and then the oxygen ion implantation is conducted through the oxide film.

2. A method of producing a SIMOX wafer according to claim 1, wherein a part or a whole of the oxide film is etched to remove particles adhered onto the oxide film after the oxygen ion implantation.

3. A method of producing a SIMOX wafer according to claim 1, wherein at least a part of the oxide film after the oxygen ion implantation is utilized as a protection film at the subsequent high-temperature annealing step without complete removal.

4. A method of producing a SIMOX wafer according to any one of claims 1-3, wherein the oxide film is formed by an oxidation treatment using an oxygen or a steam, or by a CVD treatment using silane or dichlorosilane and an oxygen.

5. A method of producing a SIMOX wafer according to any one of claims 1-3, wherein the oxide film has a thickness of 5-100 nm.

6. A method of producing a SIMOX wafer according to any one of claims 1-3, wherein an outer periphery of the oxide film is removed by etching to improve a flow of electric charge from a contact pin at the oxygen ion implantation step.