Metallization and wire bonding process for manufacturing power semiconductor devices

  • US 5,869,357 A
  • Filed: 07/29/1996
  • Issued: 02/09/1999
  • Est. Priority Date: 09/30/1993
  • Status: Expired due to Term
First Claim
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1. A metallization and bonding process for manufacturing a power semiconductor device including a plurality of elementary devices formed in an active area of a semiconductor substrate, the process comprising the steps of:

  • a) depositing a first metal layer over an entire surface of the semiconductor substrate;

    b) selectively etching the first metal layer to form a first metal plate interconnecting the elementary devices;

    c) depositing a layer of passivating material over the entire surface of the semiconductor substrate;

    d) selectively etching the layer of passivating material down to the first metal plate to define at least one bonding area represented by a substantially uncovered portion of the first metal plate, said bonding area being located directly over said active area of the semiconductor substrate and extending over a number of said plurality of elementary devices;

    e) depositing a second metal layer over the entire surface of the semiconductor substrate, the second metal layer and the first metal plate being substantially, in all of said bonding area, in direct contact to each other to form, directly over said number of elementary devices, a composite metal layer having a thickness equal to a sum of the thicknesses of the first metal plate and the second metal layer;

    f) selectively etching the second metal layer down to the layer of passivating material to remove the second metal layer outside said bonding area thus forming a second metal plate in direct contact to the first metal plate substantially in all of said bonding area; and

    g) connecting a bonding wire to a surface of the second metal plate at said bonding area, so that the bonding wire is located directly over said number of elementary devices, the second metal plate having a thickness such that a composite metal plate formed by the first metal plate and the second metal plate in said bonding area prevents the first metal plate from being perforated during the connecting of said bonding wire.

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