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US5540783A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for externally controlled closed-loop feedback digital epitaxy

Assignee: Lockheed Martin Energy Systems Inc
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Filing: 1994-05-26
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Granted: 1996-07-30
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Expires: 2014-05-26
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Abstract

Abstract A method and apparatus for digital epitaxy. The apparatus includes a pulsed gas delivery assembly that supplies gaseous material to a substrate to form an adsorption layer of the gaseous material on the substrate. Structure is provided for measuring the isothermal desorption spectrum of the growth surface to monitor the active sites which are available for adsorption. The vacuum chamber housing the substrate facilitates evacuation of the gaseous material from the area adjacent the substrate following exposure. In use, digital epitaxy is achieved by exposing a substrate to a pulse of gaseous material to form an adsorption layer of the material on the substrate. The active sites on the substrate are monitored during the formation of the adsorption layer to determine if all the active sites have been filled. Once the active sites have been filled on the growth surface of the substrate, the pulse of gaseous material is terminated. The unreacted portion of the gas pulse is evacuated by continuous pumping. Subsequently, a second pulse is applied when availability of active sites is determined by studying the isothermal desorption spectrum. These steps are repeated until a thin film of sufficient thickness is produced.

Inventors

  • 👤 Djula Eres
  • 👤 Jeffrey W. Sharp

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 03:00
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/02; C30B25/14

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 66 words
An apparatus for the formation of thin film materials comprising: means for delivering a pulse of material to a growth surface of a substrate to form an adsorption layer of said material on said growth surface; means for monitoring available active sites on said growth surface; and means for controlling the delivery of said material according to the availability of active sites on said growth surface.
Claim 2
Independent Claim 66 words
An apparatus for the formation of thin film materials comprising: means for delivering a pulse of material to a growth surface of a substrate to form an adsorption layer of said material on said growth surface; means for monitoring available active sites on said growth surface; and means for controlling the delivery of said material according to the availability of active sites on said growth surface.
Claim 3
Independent Claim 74 words
An apparatus for digital epitaxy comprising: a chamber for processing and monitoring a substrate; means for supplying a short gas pulse to form an adsorption layer on a growth surface of said substrate; means for evacuating said gas pulse from said chamber; means for generating and evaluating isothermal desorption spectra of said growth surface of said substrate to monitor the formation and evolution of said adsorption layer on said growth surface of said substrate.
Claim 4
Independent Claim 74 words
An apparatus for digital epitaxy comprising: a chamber for processing and monitoring a substrate; means for supplying a short gas pulse to form an adsorption layer on a growth surface of said substrate; means for evacuating said gas pulse from said chamber; means for generating and evaluating isothermal desorption spectra of said growth surface of said substrate to monitor the formation and evolution of said adsorption layer on said growth surface of said substrate.
Claim 5
Dependent Claim 21 words
An apparatus according to claim 2, wherein said means for supplying a short gas pulse includes a pulsed molecular beam valve.
Claim 6
Dependent Claim 29 words
An apparatus according to claim 3, wherein said pulsed molecular beam valve includes a linear translator for changing the distance between said pulsed molecular beam valve and said substrate.
Claim 7
Dependent Claim 18 words
An apparatus according to claim 2, wherein said means for evacuating includes a vacuum associated with said chamber.
Claim 8
Dependent Claim 38 words
An apparatus according to claim 2, wherein said means for evaluating comprises a laser applying a beam of light to said growth surface to produce a signal, a photodiode detecting said signal, and a microcomputer analyzing said signal.
Claim 9
Dependent Claim 23 words
An apparatus according to claim 2, further including means for heating said substrate to facilitate desorption of side products from said adsorption layer.
Claim 10
Dependent Claim 19 words
An apparatus according to claim 2, further including means for controlling the position of said substrate within said chamber.

References Cited (Backward Citations)

US5250148A Cited
US4931132A Cited
US5009485A Cited
US5164040A Cited
US5242530A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-07-30 2000-01-29 2000-07-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-07-30 2004-01-29 2004-07-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-07-30 2008-01-29 2008-07-30 $7700.00 Window Closed / Lapsed

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