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High Repetition Rate Pulsed Jet Discharge Source

IP.com Disclosure Number: IPCOM000105913D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 85K

Publishing Venue

IBM

Related People

Cromwell, EF: AUTHOR [+4]

Abstract

Disclosed is a device which produces an electrical discharge in a pulsed gas jet. The jet is formed by expanding gas from a high pressure resevoir through a pulsed valve into a vacuum. The discharge, which is directed through the center of the gas jet, has a peak current of over 1kA. The device can be operated at a repetition rate of up to 1kHz.

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High Repetition Rate Pulsed Jet Discharge Source

      Disclosed is a device which produces an electrical discharge in
a pulsed gas jet.  The jet is formed by expanding gas from a high
pressure resevoir through a pulsed valve into a vacuum.  The
discharge, which is directed through the center of the gas jet, has a
peak current of over 1kA.  The device can be operated at a repetition
rate of up to 1kHz.

      Pulsed jet discharges offer controlled sources of plasmas for
various applications including plasma etching[1], thin film
deposition[2], and vacuum ultraviolet radiation generation[3].  For
these processes, high gas densities in the jet and high peak
discharge currents are desirable.  Furthermore, a high repetition
rate and short gas pulse duration enhance the usefulness of such a
device.  These desirable operating characteristics lead to
challenging requirements on sealing, ablation of materials,
electrical insulation, plunger acceleration, and stability.  The
design presented here solves the problem of meeting these
requirements while obtaining reliable, trouble-free performance.

      A device which has the above qualities is shown in the figure.
The valve driver(16), which uses a large travel piezo-electric (pzt)
crystal, is based on a previously published device[4].  A gas
reservoir is formed by the valve body parts 1-5 and the upper housing
(see[1]).  To open the valve, the sealing o-ring, 11, is moved by the
pzt crystal, 16, via the poppet which consists of parts 12-15.  Parts
1 & 14 electrically insulate the upper valve body and the pzt crystal
from the discharge current.  Sealing tension of the valve is adjusted
by a differention screw (15).  The discharge current is carried from
a pulsed high voltage source (not shown) through the valve body (2),
a cross-shaped diaphragm (9), and the poppet tip (12) to the
discharge electrode (6).  The current is timed to coincide with the
gas jet and a directional discharge through the jet is then formed
between 6 and a...