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Curing Metal Oxide Semiconductor Defects

IP.com Disclosure Number: IPCOM000083876D
Original Publication Date: 1975-Aug-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Edmonds, HD: AUTHOR

Abstract

Crystal defects, such as occur in silicon semiconductor wafers may, become electrically active when contaminated with impurities such as metals, specifically, copper. The electrically active defects can cause metal-oxide semiconductor (MOS) device failure when they intersect the depletion width.

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Curing Metal Oxide Semiconductor Defects

Crystal defects, such as occur in silicon semiconductor wafers may, become electrically active when contaminated with impurities such as metals, specifically, copper. The electrically active defects can cause metal-oxide semiconductor (MOS) device failure when they intersect the depletion width.

Electrically active defects are prevented by first growing a thermal oxide layer on the semiconductor surface at a noncritical thickness of, for example, 500 Angstroms. Aluminum islands or stripes are next deposited by vapor deposition at a rate of about 20 Angstroms per second to a thickness of about 5000 Angstroms on the oxide layer, and the aluminum is heated beyond its melting point.

The underlying oxide and aluminum are then stripped from the semiconductor surface. This treatment has been found to prevent the formation of electrically active defects in a semiconductor material.

The process can be used to treat an entire semiconductor wafer by evaporating aluminum stripes over the wafer surface.

It is not necessary to coat the entire surface with aluminum, because it has been found that defect prevention is achieved not only where the aluminum is deposited but also in an area beyond the edge of the aluminum. Accordingly, by choosing the proper spacing between the stripes, the entire surface is effectively treated.

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