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:
Mar. 30, 1999
Filed:
Nov. 07, 1997
Weiran Kong, Sunnyvale, CA (US);
Kai-Ning Chang, San Jose, CA (US);
Integrated Silicon Solution, Inc., Santa Clara, CA (US);
Abstract
A method for reducing stray conductive material near vertical surfaces in semiconductor manufacturing processes comprising the following steps. Deposit the gate oxide, polysilicon and cap oxide layers. Apply a Poly1A mask. The Poly1A mask pattern comprises the Poly1 areas that are part of the final circuit layout as well as additional Poly1 areas that are included to provide planar surfaces to prevent stringer formation. Etch the cap, polysilicon and gate oxide layers to partially form the transistor gate structures. Form oxide spacers on the sides of the transistor gate structures. Apply a source/drain mask. Deposit source/drain dopants to form diffusions. Deposit an interlayer dielectric. Mask and pattern contacts to the diffusions and the Poly1 layer. Deposit blanket TiN/Ti layer(s). Pattern the TiN/Ti layer(s) using a TiN/Ti mask and a dry anisotropic etch. Patterning the TiN/Ti layer(s) may create TiN/Ti stringers along vertical surfaces of the interconnect layer. However, by defining the Poly1A mask pattern to leave Poly1 in pre-defined potential stringer problem areas, these surfaces remain planar and thus free of stringers. Next, apply a Poly1B mask. The Polyl1B mask is defined such that the final Poly1 pattern is the logical AND of the Poly1A mask pattern and the inverse of the Poly1B mask. Then etch the cap, polysilicon and gate oxide layers to complete formation of the transistor gate structures.