Browse Prior Art Database

NI-7% V/AG BACKMETAL PROJECT

IP.com Disclosure Number: IPCOM000006578D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2002-Jan-16
Document File: 1 page(s) / 65K

Publishing Venue

Motorola

Related People

Michael Pfeifer: AUTHOR [+4]

Abstract

Work has been done to develop the Ni-7%/Ag backmetal system. The purpose of this backmetal is to provide electrical and thermal contact between the die and the package. Many different backmetal systems are currently in use. All of these using Ni and Ag also have a barrier metal in between the Ni layer and the die. The purpose of this barrier metal layer is to prevent any di- fusion or reaction between the Ni and the Si die.

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MOTOROLA INC. Technical Developments Volume 16 August 1992

NI-7% V/AG BACKMmAL PROJECT

by Michael Pfeifer', Eric Guillet?, Bill Marline', and Mike Kottke3 Motorola, Semiconductor Products Sector 'Bipolar I Group, 'Bipolar 4 Group, 3Advanced Technology Center

   Work has been done to develop the Ni-7%/Ag backmetal system. The purpose of this backmetal is to provide electrical and thermal contact between the die and the package. Many different backmetal systems are currently in use. All of these using Ni and Ag also have a barrier metal in between the Ni layer and the die. The purpose of this barrier metal layer is to prevent any di- fusion or reaction between the Ni and the Si die.

  During the development of this new backmetal sys- tem we have investigated the following: 1) the optimum process parameters for depositing the backmetal, 2) if there is a reaction between the backmetal and the sili- con wafer which would be detrimental to the operation of assembled devices, 3) the contact resistance between the silicon and the backmetal, 4) the resistivity of the Ni-7%V alloy and the Ag, and 5) the range of thicknesses of Ni-7%V and Ag that can be used in the backmetal.

  We have found that for the assembly time and tem- perature and the normal operating temperatures it is unnecessary to have a barrier metal between the Ni alloy and the silicon. This conclusion is based on the data given in the literature which indicate that the reaction between Ni and Si occurs only for tem...