← Back to Patent Explorer
US4877573A Expired / Lapsed US ⏱️ 0.0 years remaining

Substrate holder for wafers during MBE growth

Assignee: Northrop Grumman Guidance and Electronics Co Inc
•
Filing: 1988-11-07
•
Granted: 1989-10-31
•
Expires: 2008-11-07
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A holder for supporting a compound semiconductor wafer such as GaAs during MBE heating includes a molybdenum ring, a tantalum ring for supporting the wafer therebetween uniformly about its outer edge, and a sapphire wafer, opposite the compound semiconductor wafer, fixedly attached to the molybdenum ring. The sapphire wafer prevents arsenic loss during heating and transmits infrared radiation to reach the compound semiconductor wafer.

Inventors

  • 👤 Boo Nilsson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 11:31
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; C30B23/06

Claims Analysis

Total Claims: 27
Claim 1
Independent Claim 76 words
Apparatus for holding a semi-conductor wafer during heating by radiation comprising: (a) an apertured support means defining spaced-apart faces for receiving a generally-planar backplate and a wafer in spaced-apart substantially parallel relationship to define an enclosed volume through which radiation can pass; (b) said backplate being fabricated of material selected from the group consisting of gallium phosphide, pyrolytic boron nitride and sapphire; and (c) means for retaining said backplate and said wafer in said support means.
Claim 2
Dependent Claim 76 words
Apparatus for holding a semi-conductor wafer during heating by radiation comprising: (a) an apertured support means defining spaced-apart faces for receiving a generally-planar backplate and a wafer in spaced-apart substantially parallel relationship to define an enclosed volume through which radiation can pass; (b) said backplate being fabricated of material selected from the group consisting of gallium phosphide, pyrolytic boron nitride and sapphire; and (c) means for retaining said backplate and said wafer in said support means.
Claim 3
Dependent Claim 28 words
The apparatus of claim 1 wherein said enclosed volume is sealed sufficiently to be capable of creating an overpressure of vapor emitted by said wafer during said heating.
Claim 4
Dependent Claim 22 words
The apparatus of claim 1 wherein said support means having a structure for holding said wafer around the periphery of said wafer.
Claim 5
Dependent Claim 72 words
Semi-conductor fabrication apparatus for use in a molecular beam epitaxy (MBE) growth process comprising in combination: (a) an apertured support means defining spaced-apart faces for receiving a generally-planar backplate and a semi-conductor wafer in a spaced-apart, substantially parallel relationship, said means, said backplate and said semi-conductor wafer defining an enclosed volume; (b) said backplate being fabricated of sapphire; and (c) means for retaining said backplate and said wafer in said support means.
Claim 6
Dependent Claim 72 words
Semi-conductor fabrication apparatus for use in a molecular beam epitaxy (MBE) growth process comprising in combination: (a) an apertured support means defining spaced-apart faces for receiving a generally-planar backplate and a semi-conductor wafer in a spaced-apart, substantially parallel relationship, said means, said backplate and said semi-conductor wafer defining an enclosed volume; (b) said backplate being fabricated of sapphire; and (c) means for retaining said backplate and said wafer in said support means.
Claim 7
Dependent Claim 13 words
Apparatus as defined in claim 4 wherein said wafer is fabricated of GaAs.
Claim 8
Dependent Claim 12 words
Apparatus as defined claim 4 wherein said wafer is fabricated of InP.
Claim 9
Dependent Claim 15 words
Apparatus as defined in claim 4 wherein said wafer is fabricated of a compound semi-conductor.
Claim 10
Dependent Claim 65 words
Semi-conductor fabrication apparatus for use in a molecular beam epitaxy (MBE) growth process comprising in combination: (a) an apertured support means defining spaced-apart faces for receiving a generally-planar backplate and a semi-conductor wafer in a spaced-apart, substantially parallel relationship defining an enclosed volume; (b) said backplate being fabricated of gallium phosphide; and (c) means for retaining said backplate and said wafer in said support means.
Claim 11
Dependent Claim 65 words
Semi-conductor fabrication apparatus for use in a molecular beam epitaxy (MBE) growth process comprising in combination: (a) an apertured support means defining spaced-apart faces for receiving a generally-planar backplate and a semi-conductor wafer in a spaced-apart, substantially parallel relationship defining an enclosed volume; (b) said backplate being fabricated of gallium phosphide; and (c) means for retaining said backplate and said wafer in said support means.
Claim 12
Dependent Claim 13 words
Apparatus as defined in claim 8 wherein said wafer is fabricated of GaAs.
Claim 13
Dependent Claim 13 words
Apparatus as defined in claim 8 wherein said wafer is fabricated of InP.
Claim 14
Dependent Claim 66 words
Semi-conductor fabrication apparatus for use in a molecular beam epitaxy (MBE) growth process comprising in combination: (a) an apertured support means defining spaced-apart faces for receiving a generally-planar backplate and a semi-conductor wafer in a spaced-apart, substantially parallel relationship defining an enclosed volume; (b) said backplate being fabricated of pyrolytic boron nitride; and (c) means for retaining said backplate and said wafer in said support means.
Claim 15
Dependent Claim 66 words
Semi-conductor fabrication apparatus for use in a molecular beam epitaxy (MBE) growth process comprising in combination: (a) an apertured support means defining spaced-apart faces for receiving a generally-planar backplate and a semi-conductor wafer in a spaced-apart, substantially parallel relationship defining an enclosed volume; (b) said backplate being fabricated of pyrolytic boron nitride; and (c) means for retaining said backplate and said wafer in said support means.
Claim 16
Dependent Claim 13 words
Apparatus as defined in claim 11 wherein said wafer is fabricated of GaAs.
Claim 17
Dependent Claim 13 words
Apparatus as defined in claim 11 wherein said wafer is fabricated of InP.
Claim 18
Dependent Claim 176 words
In a method for molecular beam epitaxy (MBE) growth of a film on a wafer of a first semiconductor material where the improvement comprises the steps of: (a) forming an apertured support means defining two spaced-apart faces; and (b) forming a backplate of a second material that differs from said first material, said second material being sufficiently transparent to radiation in a wavelength region that is absorbed by said wafer to allow heating of said wafer to a higher temperature than said backplate; then (c) mounting said generally-planar semi-conductor wafer adjacent to one of said two opposed faces of said apertured support means: and (d) mounting said backplate adjacent to the other of said two opposed faces of said apertured support means so that said wafer and said backplate are in a spaced-apart, substantially parallel relationship defining an enclosed volume through which infrared radiation can pass; and then (e) heating said wafer by directing radiation of said predetermined wavelength at said backplate whereby a portion of said radiation passes through said enclosed volume to said wafer.
Claim 19
Dependent Claim 176 words
In a method for molecular beam epitaxy (MBE) growth of a film on a wafer of a first semiconductor material where the improvement comprises the steps of: (a) forming an apertured support means defining two spaced-apart faces; and (b) forming a backplate of a second material that differs from said first material, said second material being sufficiently transparent to radiation in a wavelength region that is absorbed by said wafer to allow heating of said wafer to a higher temperature than said backplate; then (c) mounting said generally-planar semi-conductor wafer adjacent to one of said two opposed faces of said apertured support means: and (d) mounting said backplate adjacent to the other of said two opposed faces of said apertured support means so that said wafer and said backplate are in a spaced-apart, substantially parallel relationship defining an enclosed volume through which infrared radiation can pass; and then (e) heating said wafer by directing radiation of said predetermined wavelength at said backplate whereby a portion of said radiation passes through said enclosed volume to said wafer.
Claim 20
Dependent Claim 13 words
A method as defined in claim 14 when said wafer is of GaAs.
Claim 21
Dependent Claim 12 words
A method as defined in claim 14 employing a backplate of sapphire.
Claim 22
Dependent Claim 13 words
A method as defined in claim 16 wherein said wafer is of GaAs.
Claim 23
Dependent Claim 24 words
A method as defined in claim 16 wherein said backplate is fabricated of material from the group consisting of boron nitride and gallium phosphide.
Claim 24
Dependent Claim 14 words
A method as defined in claim 16 wherein said wafer is fabricated of InP.
Claim 25
Dependent Claim 16 words
A method as defined in claim 16 wherein said wafer is formed of a compound semi-conductor.
Claim 26
Dependent Claim 95 words
In a method for growing a layer on a wafer of semiconductor material of the type wherein radiation is directed at a backplate positioned in an MBE system intermediate said wafer and said incoming radiation, the improvement comprising the steps of: (a) forming said backplate of material that differs from said wafer; and (b) selecting the material of said backplate to be of sufficient transparency to said radiation in a wavelength region that is absorbed by said wafer material so that said wafer is heated by said radiation to a higher temperature than said backplate.
Claim 27
Dependent Claim 95 words
In a method for growing a layer on a wafer of semiconductor material of the type wherein radiation is directed at a backplate positioned in an MBE system intermediate said wafer and said incoming radiation, the improvement comprising the steps of: (a) forming said backplate of material that differs from said wafer; and (b) selecting the material of said backplate to be of sufficient transparency to said radiation in a wavelength region that is absorbed by said wafer material so that said wafer is heated by said radiation to a higher temperature than said backplate.

References Cited (Backward Citations)

US3507248A Cited
US3589936A Cited
US4492852A Cited
US4806321A Cited
US4699083A Cited
US4592307A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-10-30 1993-05-01 1993-10-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-10-30 1997-05-01 1997-10-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-10-30 2001-05-01 2001-10-31 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag