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:
Jun. 23, 1992
Filed:
Nov. 14, 1991
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
After the separating grooves has been formed, the polycrystalline silicon deposited as bonded to the single crystal substrate as a supporting base, and the polycrystalline silicon layer ground and polished until the oxide film in the area other than the separating grooves is exposed, the present invention etches the polycrystalline silicon layer on the separating grooves with mixed acid composed of hydrofluoric acid and nitric acid until its thickness equals that of the separating oxide film and subsequently removes the oxide film in the area other than the separating grooves with hydrofluoric acid, As a result, the otherwise inevitable occurrence of projections of polycrystalline silicon can be precluded. When the dielectric-separation substrate obtained by the present invention is used in manufacturing a semiconductor device, therefore, the occurrence of particles due to the chipping of the projections of polycrystalline silicon and the breakage of distributed wires in the produced device can be prevented.