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:
May. 18, 2010
Filed:
Jan. 31, 2007
Hiroaki Tomimori, Kanagawa, JP;
Hidemitsu Aoki, Kanagawa, JP;
Toshiyuki Iwamoto, Tokyo, JP;
NEC Electronics Corporation, Kanagawa, JP;
NEC Corporation, Tokyo, JP;
Abstract
According to the present invention, high-k film can be etched to provide a desired geometry without damaging the silicon underlying material. A silicon oxide filmis formed on a silicon substrateby thermal oxidation, and a high dielectric constant insulating filmcomprising HfSiOx is formed thereon. Thereafter, polycrystalline silicon layerand high dielectric constant insulating filmare selectively removed in stages by a dry etching through a mask of the resist layer, and subsequently, the residual portion of the high dielectric constant insulating filmand the silicon oxide filmare selectively removed by wet etching through a mask of polycrystalline silicon layer. A liquid mixture of phosphoric acid and sulfuric acid is employed for the etchant solution. The temperature of the etchant solution is preferably equal to or lower than 200 degree C., and more preferably equal to or less than 180 degree C.