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:
Sep. 21, 1993
Filed:
Feb. 06, 1992
Yih-Shung Lin, Carrollton, TX (US);
Lun-Tseng Lu, Grand Prairie, TX (US);
Fu-Tai Liou, Carrollton, TX (US);
Che-Chia Wei, Plano, TX (US);
John L Walters, Carrollton, TX (US);
SGS-Thomson Microelectronics, Inc., Carrollton, TX (US);
Abstract
A method is provided for forming contact vias in an integrated circuit. Initially, a first buffer layer is formed over an insulating layer in an integrated circuit. The first buffer layer has a different etch rate from the insulating layer. A second buffer layer is then formed over the first buffer layer, with the second buffer layer having an etch rate which is faster than the first buffer layer. An isotropic etch is performed to create an opening through the second buffer layer and a portion of the first buffer layer. Because the second buffer layer etches faster than the first buffer layer, the slant of the sideswalls of the opening can be controlled. An anisotropic etch is then performed to complete formation of the contact via.