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Browse Prior Art Database

Eutectic Die Bonding Process

IP.com Disclosure Number: IPCOM000084862D
Original Publication Date: 1976-Jan-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Hill, T: AUTHOR [+2]

Abstract

A technique is described for gold bonding a semiconductor die to a substrate.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

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Eutectic Die Bonding Process

A technique is described for gold bonding a semiconductor die to a substrate.

Prior art techniques for melting the gold layer on a substrate to which a semiconductor die is to be attached, involve passing an electric current through the gold layer to melt the same. Gold, which melts at 1064 degrees C, then alloys with the silicon and the combination is allowed to cool thereby bonding the semiconductor chip to the substrate. A problem which frequently occurs with this process is the inadvertent rediffusion of the diffused structures in the semiconductor chip, due to the elevated temperature at which the gold melts.

The eutectic gold-silicon alloy melts at 363 degrees C. The fusion temperature of the gold in the die bonding process can be reduced so as to approach the lower eutectic temperature, by frictionally scrubbing the semiconductor chip over the gold layer prior to the application of the heating current through the gold. This forms localized mixtures of silicon and gold having clean surfaces in mutual contact, so as to enable the formation of an alloy with a lower melting point than that for elemental gold itself. The use of the technique results in a lower temperature process for gold bonding semiconductor chips to a substrate.

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