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Preparation of AIN Substrates for Metallization and Passivation of AIN in Hydrothermal Environments

IP.com Disclosure Number: IPCOM000111292D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Egitto, FD: AUTHOR [+4]

Abstract

AIN as a substrate material for electronic packages offers some advantages over alumina-based ceramics since it has high thermal conductivity and a reduced CTE value. However, its chemical and thermal instability make it less desirable for these uses. A dry metallization process is preferred over the solution deposition methods that operate at high pH but both approaches must produce strong metal/AIN interfaces for practical applications.

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Preparation of AIN Substrates for Metallization and Passivation of
AIN in Hydrothermal Environments

      AIN as a substrate material for electronic packages offers some
advantages over alumina-based ceramics since it has high thermal
conductivity and a reduced CTE value.  However, its chemical and
thermal instability make it less desirable for these uses.  A dry
metallization process is preferred over the solution deposition
methods that operate at high pH but both approaches must produce
strong metal/AIN interfaces for practical applications.

      Direct metallization of AIN is a desirable process, but since
the surface of the substrate may need to be precleaned in steam,
hydrolysis will take place and the resulting adhesion to a metal
layer may be unacceptable.  An alternative approach to accomplish
adhesion enhancements as well as stability against hydrothermal
degradation is the deposition of a thin layer of silicon dioxide.
The deposition can be performed as a preparatory step to
metallization, and metal deposition will result in strong interaction
of metal atoms and the new surface layer.

      Adhesion measurements for substrates metallized directly or
after deposition of a thin layer of silicon dioxide (60 to 420
&angstrom.  thick) have produced average adhesion values of 933 and
4505 psi, respectively , as measured by the rivet dot pull test.
Also, these surface layers before metallization have been shown to
protect AIN surfaces from further oxi...