Browse Prior Art Database

Minimization of Thickness Variating in Coatings

IP.com Disclosure Number: IPCOM000086053D
Original Publication Date: 1976-Jul-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Sarkary, HG: AUTHOR

Abstract

Described is a process for reducing the thickness distribution variations of coating across a wafer to less than one half the original variation. The process is applicable to quartz, silicon oxide and silicon nitride coatings.

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Minimization of Thickness Variating in Coatings

Described is a process for reducing the thickness distribution variations of coating across a wafer to less than one half the original variation. The process is applicable to quartz, silicon oxide and silicon nitride coatings.

With varying metal bands on a wafer, it is difficult to obtain substantial uniformity in deposition of coatings, such as quartz, which can raise problems in etching via holes through the coating.

It has been found that with a preliminary etch of the top layer of a quartz coating in a 5:1 buffered HF solution, the uniformity of the quartz (on a wafer-to- wafer basis) can be improved from an average of 980 angstroms of standard deviation to an improved standard of deviation of 420 angstroms.

In nine runs of 16 wafer batches, each measured at 5 points (for a total of 5500 points), the preliminary etch in the 5:1 buffered HF, a substantial number of wafers had their standard deviation reduced about 1/5 (e.g., 1200 angstroms to 250 angstroms).

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