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:
Jul. 15, 2003
Filed:
Feb. 20, 2001
Nagamasa Shiokawa, Nobeoka, JP;
Asahi Kasei Microsystems Co., Ltd., Tokyo, JP;
Abstract
A high quality thermal oxide film is provided. For the purpose of the film, a cooling step is conducted after replacing an atmosphere in the diffusion furnace ( ) with a high purity gas mixture of nitrogen N 99% and oxygen O 1% after an oxidizing and an annealing steps. Then, a pump (DP) is turned on to evacuate a load-lock chamber ( ), which is then filled with nitrogen N . Then, while feeding a gas mixture of nitrogen N 99% and oxygen O 1% into the diffusion furnace ( ), a wafer boat ( ) is transferred from the diffusion furnace ( ) to the load-lock chamber ( ) (Removing step). Thus, the cooling and the removing steps are conducted under an atmosphere gas of a high purity mixture of nitrogen and a small amount of high purity oxygen free from impurities in the air. Only high purity oxygen is, therefore, introduced in an interface between a silicon substrate and an oxide film, so that a high quality thermal oxide film can be provided.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile