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:
Aug. 23, 2022
Filed:
Dec. 30, 2020
Fuji Electric Co., Ltd., Kawasaki, JP;
Yasuyuki Kawada, Tsukuba, JP;
FUJI ELECTRIC CO., LTD., Kawasaki, JP;
Abstract
Before formation of gate insulating films, an oblique ion implantation of oxygen into opposing sidewalls of trenches, from a top of an oxide film mask is performed, forming oxygen ion-implanted layers in surface regions of the sidewalls. A peak position of oxygen concentration distribution of the oxygen ion-implanted layers is inside the oxide film mask. After removal of the oxide film mask, HTO films constituting the gate insulating films are formed. During deposition of the HTO films, excess carbon occurring at the start of the deposition of the HTO films and in the gate insulating films reacts with oxygen in the oxygen ion-implanted layers, thereby becoming an oxocarbon and being desorbed. The oxygen ion-implanted layers have a thickness in a direction orthogonal to the sidewalls at most half of the thickness of the gate insulating films, and an oxygen concentration higher than any other portion of the semiconductor substrate.