The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 1994
Filed:
Sep. 30, 1992
Makoto Imura, Tokyo, JP;
Kenji Kusakabe, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A silicon wafer having a low concentration of oxygen and a silicon wafer having a high concentration of oxygen are joined and polished to prescribed thicknesses to form a semiconductor substrate according to the present invention. A region formed of the wafer having a low concentration of oxygen is used as a region where an element is formed, and a region formed of the wafer having a high concentration of oxygen produces a gettering effect on metal impurities and defects. As a DZ layer having a low concentration of oxygen, a wafer manufactured by an MCZ method or a wafer manufactured by a CZ method is used after being heat-treated at high temperature to diffuse oxygen outward. In another example, a damage layer, a polycrystalline silicon layer, an amorphous silicon layer or the like is formed between a DZ layer and an IG layer.