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:
Nov. 02, 1999
Filed:
Feb. 16, 1993
Takashi Kasuga, Kanagawa, JP;
Yoichi Tomo, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
A contact hole forming method uses a negative resist film having an absorptivity of 0.5 .mu.m.sup.-1 or above to suppress standing-wave effect in forming contact holes in a silicon dioxide film or the like underlying the negative resist film by anisotropic etching. The contact hole forming method comprises steps of: applying a negative resist having an absorptivity of 0.5 .mu.m.sup.-1 or above to the stepped surface of a stepped film formed on a substrate to form a negative resist film having a flat surface; exposing the negative resist film through a photomask to laser light emitted by a krypton fluoride excimer laser; developing the exposed negative resist film; and etching the silicon dioxide film or the like by anisotropic etching using the developed negative resist film as an etching mask and an etching gas containing a fluorocarbon or a mixture of a fluorocarbon and hydrogen to form contact holes. The negative resist film suppresses standing-wave effect, so that the contact holes can be formed in diameters accurately corresponding to the diameters of corresponding patterns of the photomask.