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HgCdTe epitaxially grown on crystalline support

Assignee: Lockheed Martin Tactical Systems Inc
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Filing: 1985-08-26
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Granted: 1987-04-07
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Expires: 2005-08-26
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Abstract

Abstract A layer of HgCdTe (15) epitaxially grown onto a crystalline support (10), e.g., of sapphire of GaAs. A CdTe substrate (5) is epitaxially grown to a thickness of between 1 micron and 5 microns on the support (10). A HgTe source (3) is spaced from the CdTe substrate (5) a distance of between 0.1 mm and 10 mm. The substrate (5) and source (3) are heated together in a thermally insulating, reusable ampoule (17) within a growth temperature range of between 500° C. and 625° C. for a growth step having a duration of between 5 minutes and 4 hours. Then an interdiffusion step is performed, in which the source (3) and substrate (5) are cooled within a temperature range of between 400° C. and 500° C. for a time of between 1 hour and 16 hours. In a first growth step embodiment, the source (3) and substrate (5) are isothermal. In a second growth step embodiment, the source (3) and substrate (5) are non-isothermal. Means are disclosed for preventing contamination of the reactants during HgTe (3) synthesis, and for polishing the HgCdTe layer (15).

Inventors

  • 👤 Robert E. Kay
  • 👤 Hakchill Chan
  • 👤 Fred Ju
  • 👤 Burton A. Bray

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 10:08
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/02; C30B25/22; C30B29/00; C30B29/10; C30B29/46; C30B29/48; H; H10; H10P; H10P14/00; H10P14/20; H10P14/22; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/2913; H10P14/2917; H10P14/2921; H10P14/32; H10P14/3202; H10P14/3224; H10P14/3232; H10P14/34; H10P14/3402; H10P14/3424; H10P14/3432; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12528

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 120 words
A method for epitaxially growing a layer of HgCdTe onto a crystalline support, comprising the steps of: epitaxially growing a CdTe substrate to a thickness of between 1 micron and 5 microns onto the support; spacing a HgTe source between 0.1 mm and 10 mm apart from the CdTe; performing a growth step in which the HgTe and CdTe are heated within a growth temperature range of between 500° C. and 625° C. for a growth time of between 5 minutes and 4 hours; and performing an interdiffusion step in which the HgTe and CdTe are cooled within an interdiffusion temperature range of between 400° C. and 500° C. for an interdiffusion time of between 1 hour and 16 hours.
Claim 2
Independent Claim 120 words
A method for epitaxially growing a layer of HgCdTe onto a crystalline support, comprising the steps of: epitaxially growing a CdTe substrate to a thickness of between 1 micron and 5 microns onto the support; spacing a HgTe source between 0.1 mm and 10 mm apart from the CdTe; performing a growth step in which the HgTe and CdTe are heated within a growth temperature range of between 500° C. and 625° C. for a growth time of between 5 minutes and 4 hours; and performing an interdiffusion step in which the HgTe and CdTe are cooled within an interdiffusion temperature range of between 400° C. and 500° C. for an interdiffusion time of between 1 hour and 16 hours.
Claim 3
Dependent Claim 20 words
The method of claim 1 wherein the spacing between the HgTe source and the CdTe substrate is approximately 2 mm.
Claim 4
Dependent Claim 22 words
The method of claim 1 wherein the support is fabricated of a material from the class of materials comprising sapphire and GaAs.
Claim 5
Dependent Claim 26 words
The method of claim 1 wherein, during the growth step, the temperature is substantially constant and substantially the same for both the source and the substrate.
Claim 6
Dependent Claim 22 words
The method of claim 1 wherein, during the growth step, the substrate is hotter than the source for at least 5 minutes.
Claim 7
Dependent Claim 28 words
The method of claim 1 wherein, during the interdiffusion step, the temperature is substantially constant and substantially the same for the source and for the substrate, if any.

References Cited (Backward Citations)

US3622405A Cited
US4418096A Cited
US4447470A Cited
US4487813A Cited
US4487640A Cited
US4588446A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-04-06 1990-10-06 1991-04-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-04-06 1994-10-06 1995-04-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-04-06 1998-10-06 1999-04-07 $7700.00 Window Closed / Lapsed

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