Browse Prior Art Database

Thermal Expansion Matched Capacitor Materials

IP.com Disclosure Number: IPCOM000119926D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 40K

Publishing Venue

IBM

Related People

Shaw, TM: AUTHOR

Abstract

Described is the use of high capacitance materials that have a thermal expansion coefficient matched to that of a substrate, such as silicon. Boundary layer capacitor materials are produced using conducting phase/ glass composites, and thermal expansion is controlled by the selection of appropriate conducting and non-conducting phases.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 79% of the total text.

Thermal Expansion Matched Capacitor Materials

      Described is the use of high capacitance materials that
have a thermal expansion coefficient matched to that of a substrate,
such as silicon.  Boundary layer capacitor materials are produced
using conducting phase/ glass composites, and thermal expansion is
controlled by the selection of appropriate conducting and
non-conducting phases.

      In the prior art, high capacitance materials have been produced
by using the so-called boundary layer approach. Typically, the micro-
structure consisted of conducting grains separated by a thin
insulating dielectric layer which was produced by controlled
oxidation of polycrystalline titanate materials, such as BaTiO3 and
SrTiO3 . However, the materials produced had a relatively high
thermal expansion coefficient, resulting in an expansion mismatch
with silicon and made the boundary layer capacitor materials
unattractive for producing integrated structure capacitors.  Ideally,
the thermal expansion coefficient of silicon should be matched by the
capacitor material.

      The concept described herein provides a means of producing a
matched thermal expansion coefficient for capacitors.  This is done
by fabricating micro-structures consisting of doped conducting
silicon grains separated by insulating layers of glass.  Such a
structure can be produced in a number of ways:  a) by sintering
silicon powders with a suitable glass; b) by pre-oxidizing the
silicon to coat the...