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US5096846A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of forming a quantum effect switching device

Assignee: Raytheon Co
•
Filing: 1990-11-02
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Granted: 1992-03-17
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Expires: 2010-11-02
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Abstract

Abstract A method for forming a quantum effect switching device is disclosed which comprises the step of forming a heterostructure substrate 10. A silicon nitride layer 22 is formed on an outer surface of the substrate 10. An aluminum mask body 30 is formed using a lift-off procedure. Aluminum mask body 30 is then used to form a silicon nitride mask body 32 from the silicon nitride layer 22 using a CF 4 /O 2 reactive ion etch process. A boron trichloride etch process is then used to form a dual column structure 34 while removing the aluminum mask body 30. A buffered HF wet etch process removes the silicon nitride mask body 32. Separate metal contacts can then be made to electrically separate points on the outer surface of the dual column structure 34.

Inventors

  • 👤 John N. Randall

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 20:06
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; B; B82; B82Y; B82Y10/00; H10D30/00; H10D30/01; H10D30/014; H10P; H10P50/00; H10P50/69; H10P50/691; H10P50/693; H10P50/694; H10D62/00; H10D62/80; H10D62/85; Y; Y10; Y10S; Y10S148/00; Y10S148/10; Y10S438/00; Y10S438/962

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 179 words
A method for forming an electronic device, comprising the steps of: forming a substrate comprising a semiconductor material and having an outer surface; forming a first mask layer comprising a first mask material and having an outer surface on the outer surface of the substrate; forming a second mask body comprising a second mask material on the outer surface of the first mask layer; forming a first mask body disposed between the second mask body and the outer surface of the substrate using a first etchant selective to the second mask and the semiconductor material relative to the first mask material; forming a column structure from the substrate inwardly form the first mask body using a second etchant selective the first mask material relative to the semiconductor material; removing the first mask body; forming a first conductive contact electrically coupled to a first portion of the outer surface of the column structure; and forming a second conductive contact electrically coupled to a second portion of the outer surface of the column structure and not contacting the first conductive contact.
Claim 2
Independent Claim 179 words
A method for forming an electronic device, comprising the steps of: forming a substrate comprising a semiconductor material and having an outer surface; forming a first mask layer comprising a first mask material and having an outer surface on the outer surface of the substrate; forming a second mask body comprising a second mask material on the outer surface of the first mask layer; forming a first mask body disposed between the second mask body and the outer surface of the substrate using a first etchant selective to the second mask and the semiconductor material relative to the first mask material; forming a column structure from the substrate inwardly form the first mask body using a second etchant selective the first mask material relative to the semiconductor material; removing the first mask body; forming a first conductive contact electrically coupled to a first portion of the outer surface of the column structure; and forming a second conductive contact electrically coupled to a second portion of the outer surface of the column structure and not contacting the first conductive contact.
Claim 3
Dependent Claim 106 words
The method of claim 1 wherein said step of forming a substrate comprises the steps of: forming a source layer having an outer surface; forming, on the outer surface of the source layer, a first tunnel barrier layer having an outer surface; forming, on the outer surface of the first tunnel barrier layer, a quantum well layer having an outer surface; forming, on the outer surface of the quantum well layer, a second tunnel barrier layer having an outer surface; and forming, on the outer surface of the second tunnel barrier layer, a drain layer having an outer surface comprising the outer surface of the substrate.
Claim 4
Dependent Claim 27 words
The method of claim 2 wherein said steps of forming source, quantum well and drain layers each comprise the step of forming a layer comprising gallium arsenide.
Claim 5
Dependent Claim 28 words
The method of claim 2 wherein said steps of forming first and second tunnel barrier layers each comprise the step of forming a layer comprising aluminum gallium arsenide.
Claim 6
Dependent Claim 114 words
The method of claim 1 wherein said step of forming a second mask body comprises the steps of: forming a resist layer disposed on said outer surface of said first mask layer; removing a selected portion of said resist layer to expose a selected portion of said first mask layer; depositing said second mask material covering said resist layer and said exposed portion of said first mask layer; and removing the remainder of said resist layer and portions of said second mask material not covering said exposed portion of said first mask layer, said second mask body comprising the portion of said second mask material covering said exposed portion of said first mask layer.
Claim 7
Dependent Claim 24 words
The method of claim 1 wherein said step of forming a first mask layer comprises the step of forming a layer comprising silicon nitride.
Claim 8
Dependent Claim 23 words
The method of claim 1 wherein said step of forming a second mask body comprises the step of forming a body comprising aluminum.
Claim 9
Dependent Claim 12 words
The method of claim 1 wherein said first etchant comprises carbon tetrafluoride.
Claim 10
Dependent Claim 14 words
The method of claim 1 wherein said first etchant comprises carbon tetrafluoride and oxygen.
Claim 11
Dependent Claim 12 words
The method of claim 1 wherein said second etchant comprises boron trichloride.
Claim 12
Independent Claim 164 words
A method form forming an electronic device, comprising the steps of: forming a substrate comprising a semiconductor material and having an outer surface; forming a silicon nitride layer having an outer surface on the surface of the substrate; forming an aluminum mask body on the outer surface of the silicon nitride layer; forming a silicon nitride mask body disposed between the aluminum mask body and the outer surface of the substrate using a first etchant selective to aluminum and the semiconductor material relative to silicon nitride; forming a column structure from the substrate inwardly from the silicon nitride body using a second etchant selective to silicon nitride relative to the semiconductor material; removing the silicon nitride mask body; forming a first conductive contact electrically coupled to a first portion of the outer surface of the column structure; and forming a second conductive contact electrically coupled to a second portion of the outer surface of the column structure and not contacting the first conductive contact.
Claim 13
Independent Claim 164 words
A method form forming an electronic device, comprising the steps of: forming a substrate comprising a semiconductor material and having an outer surface; forming a silicon nitride layer having an outer surface on the surface of the substrate; forming an aluminum mask body on the outer surface of the silicon nitride layer; forming a silicon nitride mask body disposed between the aluminum mask body and the outer surface of the substrate using a first etchant selective to aluminum and the semiconductor material relative to silicon nitride; forming a column structure from the substrate inwardly from the silicon nitride body using a second etchant selective to silicon nitride relative to the semiconductor material; removing the silicon nitride mask body; forming a first conductive contact electrically coupled to a first portion of the outer surface of the column structure; and forming a second conductive contact electrically coupled to a second portion of the outer surface of the column structure and not contacting the first conductive contact.
Claim 14
Dependent Claim 106 words
The method of claim 11 wherein said step of forming a substrate comprises the steps of: forming a source layer having an outer surface; forming, on the outer surface of the source layer, a first tunnel barrier layer having an outer surface; forming, on the outer surface of the first tunnel barrier layer, a quantum well layer having an outer surface; forming, on the outer surface of the quantum well layer, a second tunnel barrier layer having an outer surface; and forming, on the outer surface of the second tunnel barrier layer, a drain layer having an outer surface comprising the outer surface of the substrate.
Claim 15
Dependent Claim 27 words
The method of claim 12 wherein said steps of forming source, quantum well and drain layers each comprise the step of forming a layer comprising gallium arsenide.
Claim 16
Dependent Claim 28 words
The method of claim 12 wherein said steps of forming first and second tunnel barrier layers each comprise the step of forming a layer comprising aluminum gallium arsenide.
Claim 17
Dependent Claim 107 words
The method of claim 11 wherein said step of forming an aluminum mask body comprises the steps of: forming a resist layer disposed on said outer surface of said silicon nitride layer; removing a selected portion of said resist layer to expose a selected portion of said silicon nitride layer; depositing aluminum covering said resist layer and said exposed portion of said silicon nitride layer; and removing the remainder of said resist layer and portions of said aluminum not covering said exposed portion of said silicon nitride layer, said aluminum mask body comprising the portion of said aluminum covering said exposed portion of said silicon nitride layer.
Claim 18
Dependent Claim 12 words
The method of claim 11 wherein said first etchant comprises carbon tetrafluoride.
Claim 19
Dependent Claim 14 words
The method of claim 11 wherein said first etchant comprises carbon tetrafluoride and oxygen.
Claim 20
Dependent Claim 12 words
The method of claim 11 wherein said second etchant comprises boron trichloride.

References Cited (Backward Citations)

US4472237A Cited
US4503447A Cited
JPS59232423A Cited
JPS60231331A Cited
US4912531A Cited
US4783427A Cited
US4980312A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-03-17 1995-09-16 1996-03-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-03-17 1999-09-16 2000-03-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-03-17 2003-09-16 2004-03-17 $7700.00 Window Closed / Lapsed

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