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Method of Adjusting the Heating Coil in Pancake Epitaxial Systems

IP.com Disclosure Number: IPCOM000122674D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 90K

Publishing Venue

IBM

Related People

Kuge, HH: AUTHOR

Abstract

In "pancake" epitaxial systems, the wafers to be processed are arranged in recesses of the susceptor which is induction-heated, disk-shaped and made of graphite.

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This is the abbreviated version, containing approximately 52% of the total text.

Method of Adjusting the Heating Coil in Pancake Epitaxial Systems

      In "pancake" epitaxial systems, the wafers to be
processed are arranged in recesses of the susceptor which is
induction-heated, disk-shaped and made of graphite.

      The spiral heating coil, positioned below the susceptor in a
reaction chamber, is supported at particular points defined by
horizontally adjustable support screws.

      The figure is a plan view of the coil S and the support points
or screws 1-32 along with the relevant numbering.  To ensure that the
wafers are uniformly heated, the spacing of the coils from the
susceptor must correspond to a particular profile.  This is obtained
by adjusting screws 1-32.

      The previously employed empirical method, in which the optimal
adjustment of the heating coil was individually determined for each
epitaxial reactor as a function of layer thicknesses grown in test
runs, is replaced by a space measurement method.  The optimal profile
is determined once for a particular reactor, measured and used for
other reactors.  The described method is substantially based on
plotting the adjustment heights of the support screws 1-32 for coil S
relative to their distance from the spiral center.  Such a plot
allows the coil profile to be readily analytically determined and
verified at a glance.  In this manner, corrections and their
magnitude are immediately visible in full from the adjusted screw
heights.

      In addition to providing a readily implementabl...