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:
Jan. 15, 1991
Filed:
Jan. 03, 1989
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
The main surface of a first semiconductor substrate is bonded to the main surface of a second semiconductor substrate with an insulation film interposed therebetween to form a composite substrate. The first semiconductor substrate and insulation film are selectively etched to form an etched portion which reaches at least the second semiconductor substrate. An impurity layer with an impurity concentration different from that of the first semiconductor substrate is formed on or in the surface area exposed to the etched portion of the first and second semiconductor substrates. An epitaxial layer having an impurity concentration different from that of the impurity layer is formed in the etched portion. The first semiconductor substrate, impurity layer and epitaxial layer are planarized. The first semiconductor substrate, impurity layer and epitaxial layer are etched to make a pattern of the impurity layer on the surface of the composite substrate and the composite semiconductor substrate is aligned for formation of elements based on the pattern. The elements are formed in the composite substrate thus aligned.