Browse Prior Art Database

Equipment for Improved Thin Film Sputter System Throughput and Disk Quality

IP.com Disclosure Number: IPCOM000101761D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Edmonson, DA: AUTHOR [+4]

Abstract

Disclosed is a technique, tooling with process, that teaches how to more thoroughly desorb water vapor from substrates in a vacuum processing apparatus. The concept combines the use of quartz lamps run at white heat (2200 degrees F) with a high volume laminar flow Ar gas shower. In this embodiment, incidental heating must be tolerated or auxiliary cooling provided. The quartz lamps, when run in this manner, produce large numbers of photons with sufficient energy to excite the ground state vibrational bands of the water molecule. These vibrationally excited structures literally leap off the surface because the surface adsorption energy of water on metal is much less than these resonance energies. Once desorbed, the laminar flow of Ar sweeps the vapor away from the pallet and out the pump exhaust, thus limiting readsorption.

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Equipment for Improved Thin Film Sputter System Throughput and Disk Quality

       Disclosed is a technique, tooling with process, that
teaches how to more thoroughly desorb water vapor from substrates in
a vacuum processing apparatus.  The concept combines the use of
quartz lamps run at white heat (2200 degrees F) with a high volume
laminar flow Ar gas shower.  In this embodiment, incidental heating
must be tolerated or auxiliary cooling provided.  The quartz lamps,
when run in this manner, produce large numbers of photons with
sufficient energy to excite the ground state vibrational bands of the
water molecule.  These vibrationally excited structures literally
leap off the surface because the surface adsorption energy of water
on metal is much less than these resonance energies.  Once desorbed,
the laminar flow of Ar sweeps the vapor away from the pallet and out
the pump exhaust, thus limiting readsorption.

      Fig. 1 is a plot of flux vs. energy for a black body at
2200 degrees F; this describes the photon output of the quartz lamps.
Also shown on this plot are the spectral excitation bands of water,
(v1,v2,v3) from (0,0,0) ground state.  All of these bands are
optically allowed and are excited to a large degree. In contrast, the
usual practice is to run heaters at a low constant red heat of 400 to
500 degrees F.  The black body spectrum of this radiation source
peaks at 1/3 the energy and at 1/10 the intensity of the higher
temperature source.  Direc...