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:
Oct. 07, 1997
Filed:
Apr. 04, 1995
Tetsuji Nagayama, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A method for producing a semiconductor device in which dry etching properties are rendered compatible with satisfactory anti-reflection characteristics in far-infrared lithography. An anti-reflective layer 6 is made up of a lower anti-reflective layer 6.sub.L of SiO.sub.X having a relatively low Si ratio and an upper anti-reflective layer 6.sub.H of SiO.sub.X having a relatively high Si ratio. After forming a resist pattern 7, the upper anti-reflective layer 6.sub.H and the lower anti-reflective layer 6.sub.U are etched using the etching conditions for Si and those for SiO.sub.X, respectively. Such variation in the Si ratio along the film thickness is realized by controlling the CVD film-forming conditions or Si.sup.+ ion implantation. Since the upper anti-reflective layer 6.sub.H has a refractive index higher than that of the lower anti-reflective layer 6.sub.L of SiO.sub.X, the standing wave suppression effect is improved. Since the films 6.sub.U, 6.sub.L are etched under respective optimum conditions, shape anisotropy may be realized. Film formation is not difficult to achieve because the elementary composition of the anti-reflective layer 6 on the whole is uniform.