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. 21, 1997
Filed:
Feb. 02, 1996
Koichiro Inazawa, Tokyo, JP;
Shin Okamoto, Kofu, JP;
Hisataka Hayashi, Yokohama, JP;
Takaya Matsushita, Yokkaichi, JP;
Tokyo Electron Limited, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A plasma etching apparatus has a lower electrode for supporting a semiconductor wafer in a processing room, an upper electrode opposite to the lower electrode, and an RF power supply for applying an RF power across the upper and lower electrodes. An SiN layer as an underlayer having a shoulder portion, and an SiO.sub.2 layer covering the SiN layer are disposed on the wafer. A contact hole is formed in the SiO.sub.2 layer by etching so as to expose the shoulder portion of the SiN layer. A processing gas contains C.sub.4 F.sub.8 and CO. To set the etching selection ratio of SiO.sub.2 /SiN, the discharge duration of each part of the processing gas is used as a parameter. The progress of dissociation of C.sub.4 F.sub.8 is controlled by selecting the discharge duration. The discharge duration is determined by the residence time of each part of the processing gas and the application time of an RF power.