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Process for Removing Wafer Surface Contaminants

IP.com Disclosure Number: IPCOM000078418D
Original Publication Date: 1973-Jan-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Greer, SE: AUTHOR [+2]

Abstract

The present process provides a method of removing pipe and defect inducing contaminants from semiconductor wafer surfaces.

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Process for Removing Wafer Surface Contaminants

The present process provides a method of removing pipe and defect inducing contaminants from semiconductor wafer surfaces.

Although chemical etching of wafer surfaces has been previously used where the wafer is polished by a relatively coarse procedure such as buffing, etching subsequent to a finer wafer preparation procedure, such as mechanical-chemical polishing, has not been conventionally used.

It has been found that even with such fine polishing procedures, etching is necessary for wafer preparation. The polishing procedure tends to produce ion contamination, particularly copper ion contamination, on the wafer surface. In high-density, large-scale integrated circuits, even the presence of small amounts of copper or other metallic ions prior to the high-heat processing of the wafer during fabrication induces pipes and other defects in the integrated circuit. However, an etching of the surface, particularly with "I Etch" to remove in the order of 0.5 microns of both sides of a silicon wafer surface prior to the first high- heat processing step will substantially reduce contamination problems. "I Etch" is Prepared as follows:

Mix HF, glacial acetic acid, HNO(3) in 1:2:5 ratio. Saturate the above solution with iodine. Allow 24 hour saturation period. Dilute the above stock solution 1:5 ratio with HNO(3).

The addition of a chelating agent, such as ethylenediamine tetraacetic acid (EDTA) in amounts to saturate the I...