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US5604154A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of manufacturing coulamb blockade element using thermal oxidation

Assignee: NTT Inc
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Filing: 1995-10-20
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Granted: 1997-02-18
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Expires: 2015-10-20
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Abstract

Abstract A Coulomb-blockade element includes a silicon layer formed on a substrate through an insulating film. The silicon layer includes a narrow wire portion and first and second electrode portions. The narrow wire portion serves as a conductive island for confining a charge. The first and second electrode portions are formed to be connected to the two ends of the narrow wire portion and are wider than the narrow wire portion. Each of the first and second electrode portions has constrictions on at least one of the upper and lower surfaces thereof, which make a portion near the narrow wire portion thinner than the narrow wire portion.

Inventors

  • 👤 Yasuo Takahashi
  • 👤 Masao Nagase
  • 👤 Akira Fujiwara

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 01:18
CPC Classifications
B; B82; B82Y; B82Y10/00; H; H10; H10D; H10D30/00; H10D30/01; H10D30/014; H10D30/40; H10D30/402; Y; Y10; Y10S; Y10S977/00; Y10S977/902; Y10S977/932; Y10S977/936; Y10S977/937

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 103 words
A method of manufacturing a Coulomb-blockade element comprising: the step of processing a silicon layer formed on a substrate through an insulating film into a shape including a narrow wire portion serving as a conductive island for confining a charge, and first and second electrode portions at two ends of said narrow wire portion, each of said first and second electrode portions being wider than said narrow wire portion; and the thermal oxidation step of thermally oxidizing said silicon layer, said first and second electrode portions being formed to be thinner than said narrow wire portion at positions near said narrow wire portion.
Claim 2
Independent Claim 103 words
A method of manufacturing a Coulomb-blockade element comprising: the step of processing a silicon layer formed on a substrate through an insulating film into a shape including a narrow wire portion serving as a conductive island for confining a charge, and first and second electrode portions at two ends of said narrow wire portion, each of said first and second electrode portions being wider than said narrow wire portion; and the thermal oxidation step of thermally oxidizing said silicon layer, said first and second electrode portions being formed to be thinner than said narrow wire portion at positions near said narrow wire portion.
Claim 3
Dependent Claim 23 words
A method according to claim 1, wherein an insulating film containing silicon is formed on said silicon layer before the thermal oxidation step.
Claim 4
Dependent Claim 15 words
A method according to claim 2, wherein said insulating film is a silicon nitride film.
Claim 5
Independent Claim 84 words
A method of manufacturing a Coulomb-blockade element comprising: the step of processing a silicon layer formed on a substrate through an insulating film into a shape including a plurality of narrow wire portions serving as conductive islands for confining charges, and a connecting portion serving as a branching or bending point for coupling said narrow wire portions to each other; and the thermal oxidation step of thermally oxidizing said silicon layer, said connecting portion being formed to be thinner than said narrow wire portion.
Claim 6
Independent Claim 84 words
A method of manufacturing a Coulomb-blockade element comprising: the step of processing a silicon layer formed on a substrate through an insulating film into a shape including a plurality of narrow wire portions serving as conductive islands for confining charges, and a connecting portion serving as a branching or bending point for coupling said narrow wire portions to each other; and the thermal oxidation step of thermally oxidizing said silicon layer, said connecting portion being formed to be thinner than said narrow wire portion.
Claim 7
Dependent Claim 61 words
A method according to claim 4, wherein said silicon layer before the thermal oxidation step includes at least one electrode portion which is connected to an end of said narrow wire portion and is wider than said narrow wire portion, said electrode portion being formed to be thinner than said narrow wire portion at a position near said narrow wire portion.
Claim 8
Dependent Claim 56 words
A method according to claim 4, wherein said silicon layer before the thermal oxidation step includes at least one electrode portion which is wider than said narrow wire portion and connected to one end of said narrow wire portion such that said electrode portion becomes wider with an increase in distance from said narrow wire portion.
Claim 9
Dependent Claim 23 words
A method according to claim 4, further comprising forming an insulating film containing silicon on said silicon layer before the thermal oxidation step.
Claim 10
Dependent Claim 15 words
A method according to claim 7, wherein said insulating film is a silicon nitride film.

References Cited (Backward Citations)

US5401980A Cited
JPH0590567A Cited
US5422496A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-02-18 2000-08-19 2001-02-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-02-18 2004-08-19 2005-02-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-02-18 2008-08-19 2009-02-18 $7700.00 Window Closed / Lapsed

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