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. 26, 1994
Filed:
Jun. 21, 1991
Toshiaki Ogawa, Hyogo, JP;
Hiroshi Morita, Hyogo, JP;
Tomoaki Ishida, Hyogo, JP;
Kenji Kawai, Hyogo, JP;
Moriaki Akazawa, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A principal feature of the present invention is to clean a surface of a semiconductor substrate without providing a damaged layer to the surface thereof. A native oxide film formed on the surface of a silicon substrate is etched by plasma employing a gas containing fluorine. The surface of the semiconductor substrate is again subjected to plasma etching by employing a gas containing fluorine in order to remove a surface damaged layer and a fluorocarbon layer formed in the above step of plasma etching. The semiconductor substrate surface is irradiated with ultraviolet rays under a low pressure in order to dissociate and remove fluorine atoms chemically adsorbed to the semiconductor substrate surface upon the latter plasma etching.