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:
Apr. 27, 1999
Filed:
Mar. 24, 1997
Hidemitsu Egawa, Tokyo, JP;
Kabushiki Kaisha Toshiba, , JP;
Abstract
A trench 13 is formed to isolate a first region 11a and a second region 11b where elements of a semiconductor substrate 11 such as a silicon substrate are formed, and a lamination layer of a first silicon oxide layer 14 having a silicon excess stoichiometry (SiO.sub.x ; 2<x) and a second silicon oxide layer 15 (SiO.sub.2) having an equilibrium composition is filled in the trench 13. The second silicon oxide layer is hydrated. In addition, by heating the semiconductor substrate 11, the first silicon oxide layer 14 is oxidized into the second silicon oxide layer 15 (SiO.sub.2) having an equilibrium composition. At this time, the first silicon oxide layer 14 has its volume expanded while it is oxidized into the second silicon oxide layer 15 having an equilibrium composition, while the second silicon oxide layer 15 is contracted due to dehydration by the heating treatment and removal of a defective lattice. Therefore, the volume expansion of the first silicon oxide layer 14 is offset by the volume contraction of the second silicon oxide layer 15 to reduce extensively a stress to be applied to the semiconductor substrate 11, so that the silicon oxide layer filled in the trench 13 can be densified.