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:
May. 30, 1995
Filed:
Mar. 18, 1994
Yoshiko Kokawa, Hyogo, JP;
Kenji Kusakabe, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Toyko, JP;
Abstract
A semiconductor substrate allowing reduction of crystal defects in a device formation region of an epitaxial silicon layer and allowing control of the amount of internal precipitation defects of the single crystal silicon substrate, a method of manufacturing such semiconductor substrate, and a semiconductor device utilizing such semiconductor substrate are disclosed. The semiconductor substrate includes a single crystal silicon substrate, an epitaxial silicon layer, and a polycrystalline silicon layer. The interstitial oxygen concentration of the single crystal silicon substrate is set within the range of 12.5-14.0.times.10.sup.17 (atoms/cm3) according to the old ASTM specification. The epitaxial silicon layer is formed on the top surface of the single crystal silicon substrate. The polycrystalline silicon layer is formed at least on the rear surface of the single crystal silicon substrate to a thickness of at least 1 .mu.m.