Browse Prior Art Database

Etch Rate Control Method

IP.com Disclosure Number: IPCOM000080159D
Original Publication Date: 1973-Nov-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Hoekstra, JP: AUTHOR

Abstract

In the process of chemically delineating patterns in the manufacture of solid-state devices, the problem that is confronted therein is the occurrence of a varying etch rate across the substrate which are caused by temperature variations and/or gas formation. This varying etch rate prevents dimensional stability of the patterns to be placed in the delineated configuration.

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Etch Rate Control Method

In the process of chemically delineating patterns in the manufacture of solid- state devices, the problem that is confronted therein is the occurrence of a varying etch rate across the substrate which are caused by temperature variations and/or gas formation. This varying etch rate prevents dimensional stability of the patterns to be placed in the delineated configuration.

Heretofore, in order to insure that all patterns were properly delineated, the etch time had to be increased by as much as 50% (overetching) to obtain a clean etched pattern. Such overetching, however, removed the undesired material in one area and, as a consequence thereof, changed the size of the pattern in other areas. Since there has been a trend to make substrates larger and patterns smaller, much emphasis has been put on the chemical etch process and, concomitantly, the undesirable "overetching" to correct for varying etch rates has to be eliminated or at least minimized.

There is described herein a technique that corrects for variation in etch rate across the substrate, and thereby enables the minimization or elimination of overetching. To carry out this technique, there is utilized an apparatus such as shown in the figure.

The latter apparatus is effectively a monitor and comprises the vessel 10 which contains the etch bath 12. The structure 14 is a substrate holder which holds the substrate 16, the substrate having an oxide on both sides thereof 17 and 19. The numeral 18 designates a field on the f...