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Browse Prior Art Database

Annealing Test Method

IP.com Disclosure Number: IPCOM000051394D
Original Publication Date: 1981-Jan-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Engelke, H: AUTHOR [+4]

Abstract

This article describes a method which permits silicon monocrystals to b very rapidly and economically classified by wet etching, using a particular mask configuration.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 68% of the total text.

Page 1 of 1

Annealing Test Method

This article describes a method which permits silicon monocrystals to b very rapidly and economically classified by wet etching, using a particular mask configuration.

Processes, such as hot diffusions at very high concentrations, implantation or dry etching with ions and electron beam lithography, used to produce integrated circuits intolerably affect the surface of silicon wafers. For this reason, immediately after one of these processes, the effect of an etchant on the destroyed silicon monocrystal or the monocrystal restored by annealing is made visible, using an SiO(2) mask.

The method described herein utilizes the fact that a destroyed silicon monocrystal is isotropically etched, whereas a non-destroyed monocrystal or a monocrystal restored by annealing is anisotropically etched, so that different crystallographic planes are etched at different speeds. The etch speed of the (111)-plane of the silicon monocrystal is about 20 times slower than that of the (100)-plane.

An SiO(2) mask is placed on a (100)-silicon wafer in such a manner that its apertured edges are exactly parallel to the four (111)-planes. A sufficiently long etch period also leads to etching in the (111)-plane, so that the SiO(2) mask is underetched, producing a very sharp and straight line at the point where the (111)-plane intersects the (100)-plane. The quality of this line is superior to that of the lithographically defined SiO(2) mask edge.

If the same SiO(2) mask is...