Browse Prior Art Database

Susceptor for Rapid Thermal Annealing of GaAs

IP.com Disclosure Number: IPCOM000119470D
Original Publication Date: 1991-Jan-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 1 page(s) / 48K

Publishing Venue

IBM

Related People

de Souza, JP: AUTHOR [+3]

Abstract

Disclosed is a susceptor where the susceptor is heated uniformly by radiation from a rapid thermal processing machine, and the heat is transferred to a semiconductor wafer, such as a GaAs wafer, from the uniformly heated susceptor by conduction through a gas instead of radiatively.

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Susceptor for Rapid Thermal Annealing of GaAs

      Disclosed is a susceptor where the susceptor is heated
uniformly by radiation from a rapid thermal processing machine, and
the heat is transferred to a semiconductor wafer, such as a GaAs
wafer, from the uniformly heated susceptor by conduction through a
gas instead of radiatively.

      Rapid Thermal Processing of GaAs wafers is difficult because
the absorption and emission of radiant energy is non-uniform, leading
to non-uniform heating and cooling, and consequent temperature
gradients which generate slip dislocations.

      The problem of non-uniform heating and cooling is then a
problem of heat transfer through a gas rather than heat transfer from
radiative surfaces, and the heat transfer is easier to calculate  and
control.

      Since the GaAs wafers are flat to within a micron over the
entire surface, and since the susceptor can be made of a material
like silicon or graphite which is also flat to within a micron, we
can arrange the wafer to be kept about 10 microns from the susceptor
on one side.  It is assumed that the other side of the wafer is much
further from the susceptor. If the space between the wafer and the
susceptor is then filled with a gas which has good heat transfer
properties, like helium, the pressure can be adjusted so that the
mean free path of the helium is also about 10 microns.  This will
maximize the heat transfer rate from the susceptor to the wafer and
ensure that the w...