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Temperature Controlled Filter Arrangement for Gases

IP.com Disclosure Number: IPCOM000108560D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 38K

Publishing Venue

IBM

Related People

Krapf, E: AUTHOR [+2]

Abstract

As the density and speed of integrated microelectronic circuits increase, their structural size decreases. As a result, there is also a decrease in the size of defect-inducing particles in the low submicron range. At the same time, other chemical impurities, which occur in the form of gases under normal conditions, have to be dealt with on an ever increasing scale.

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Temperature Controlled Filter Arrangement for Gases

       As the density and speed of integrated microelectronic
circuits increase, their structural size decreases.  As a result,
there is also a decrease in the size of defect-inducing particles in
the low submicron range.  At the same time, other chemical
impurities, which occur in the form of gases under normal conditions,
have to be dealt with on an ever increasing scale.

      When filter elements used to filter process gases are
unintentionally heated up by the ambient temperatures in process
equipment or in response to a desired heating of the filters for the
purpose of curing, the reduction of adsorptive forces has been found
to cause a release of previously adsorptively bound particle
impurities and a desorption of aerosols and gaseous matter.  This
effect is being observed in all standard gas filters.

      The release of defect-inducing impurities by such standard
filters with plastic, metal and ceramic membranes may be avoided as
follows:
a)   Preventing the membrane from becoming heated during use
(insulation).
b)   Using appropriate cooling means (Peltier elements, cooling
shields, and the like) to obtain suitably low temperatures for
improving the filter's retention rate.
c)   Performing curing steps in a by-pass or separate system rather
than in the operating gas flow.

      These measures allow removing particles and contaminants with
diameters of > 0.003 mm from process gas flow...