← Back to Patent Explorer
US4566937A Expired / Lapsed US ⏱️ 0.0 years remaining

Electron beam enhanced surface modification for making highly resolved structures

Assignee: United States Department of Energy
•
Filing: 1984-10-10
•
Granted: 1986-01-28
•
Expires: 2004-10-10
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A method for forming high resolution submicron structures on a substrate is provided by direct writing with a submicron electron beam in a partial pressure of a selected gas phase characterized by the ability to dissociate under the beam into a stable gaseous leaving group and a reactant fragment that combines with the substrate material under beam energy to form at least a surface compound. Variations of the method provide semiconductor device regions on doped silicon substrates, interconnect lines between active sites, three dimensional electronic chip structures, electron beam and optical read mass storage devices that may include color differentiated data areas, and resist areas for use with selective etching techniques.

Inventors

  • 👤 John R. Pitts

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 02:32
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F7/2051; G03F7/2059; C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/10; C23F; C23F4/00; G03F7/004; G11; G11B; G11B11/00; G11B7/00; G11B7/24; G11B9/00; G11B9/10; H; H10; H10P; H10P32/00; H10P32/10; H10P32/12; H10P32/14; H10P32/1408; H10P32/17; H10P32/171; H10P95/00; H10P95/90; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/057; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6314; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69391; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/949

Claims Analysis

Total Claims: 28
Claim 1
Independent Claim 134 words
A method of defining high resolution submicron structures on a substrate surface, comprising: (a) locating a substrate surface within a vacuum chamber together with a partial pressure of a selected gas phase material that is capable of forming as dissociation products under an electron beam a stable gaseous leaving group and a reactant fragment capable of chemically bonding with the material of the substrate surface to form a stable compound under the conditions of the vacuum chamber; and (b) applying a first electron beam of a first beam energy and of submicron beam width through the gas phase to a defined submicron-dimensioned location on said substrate surface for a time sufficient and in a dose sufficient to form at said defined location a surface compound consisting of the reactant fragment and the substrate material.
Claim 2
Independent Claim 134 words
A method of defining high resolution submicron structures on a substrate surface, comprising: (a) locating a substrate surface within a vacuum chamber together with a partial pressure of a selected gas phase material that is capable of forming as dissociation products under an electron beam a stable gaseous leaving group and a reactant fragment capable of chemically bonding with the material of the substrate surface to form a stable compound under the conditions of the vacuum chamber; and (b) applying a first electron beam of a first beam energy and of submicron beam width through the gas phase to a defined submicron-dimensioned location on said substrate surface for a time sufficient and in a dose sufficient to form at said defined location a surface compound consisting of the reactant fragment and the substrate material.
Claim 3
Dependent Claim 101 words
The method of claim 1, wherein said substrate surface comprises a metal capable of forming a compound of a first predetermined color under the energy of an electron beam with said reactant fragment, doped with a metal species at designated locations capable of imparting a second predetermined color to the compound of the substrate material and the reactant fragment, further comprising scanning the substrate surface with a plurality of at least two light beams of different colors; and detecting the reflectances of the light beams at said defined location on the substrate surface for the frequencies of the light beams employed.
Claim 4
Dependent Claim 44 words
The method of claim 1, wherein said substrate surface comprises semiconductor material and said gas phase consists essentially of a gas having a dopant as a reactant fragment, said dopant being capable of combining with the semiconductor material to form an active device region.
Claim 5
Dependent Claim 45 words
The method of claim 3, further comprising, at least during the application of the electron beam to the substrate, cooling the mean temperature of the substrate surface to reduce thermal diffusion of the dopant into the substrate material outside the defined area of beam impingement.
Claim 6
Dependent Claim 68 words
The method of claim 3, wherein said first electron beam is of a beam energy adapted to cause dissociation of said gas phase material, and further comprising: simultaneously with application of said first beam, applying a second electron beam of a second beam energy to said defined location, the second beam energy being adapted to cause diffusion of the dopant into the substrate material at said defined location.
Claim 7
Dependent Claim 33 words
The method of claim 1, further comprising: after applying the electron beam, etching the substrate surface by a selective means for removing unreacted substrate material preferentially to the removal of reacted substrate material.
Claim 8
Dependent Claim 54 words
The method of claim 1, wherein said substrate surface comprises a metallic element capable of forming a compound having a standard heat of formation and a standard free energy of formation with absolute value greater than 80 (kcal./mole) metal atom; and the gas phase reactant comprises a molecule containing oxygen as a reactant fragment.
Claim 9
Dependent Claim 26 words
The method of claim 7, wherein said gas phase is chosen from the group consisting of: carbon dioxide nitrous oxide nitrogen dioxide water vapor and oxygen.
Claim 10
Dependent Claim 38 words
The method of claim 7, wherein said substrate material is chosen from the group consisting of: aluminum, antimony, barium, beryllium, boron, calcium, chromium, iron, magnesium, manganese, molybdenum, silicon, strontium, tantalum, tin, titanium, tungsten, uranium, vanadium, zinc, and zirconium.
Claim 11
Dependent Claim 19 words
The method of claim 9, wherein said substrate material comprises an alloy of an element listed in claim 9.
Claim 12
Dependent Claim 61 words
The method of claim 1, wherein the submicron structures are defined at selected ones of a plurality of predetermined locations on a substrate surface defining a mass storage device, and further comprising: scanning said plurality of predetermined locations with an electron beam under vacuum; and detecting the presence of said structures at the selected locations by an electron beam analysis technique.
Claim 13
Independent Claim 174 words
A method of forming submicron structures by electron beam enhanced surface modification of a substrate, including the steps of: (a) locating a substrate surface within an atmosphere of a partial pressure of a selected gas phase material that is capable of forming as dissociation products a reactant fragment and a stable leaving group when subjected to an electron beam; (b) writing a beam exposure pattern directly on said substrate surface by applying to the surface an electron beam of submicron width through the gas phase to cause dissociation of the gas phase and accumulation of the reactant fragment at the interface of the beam and the substrate surface; (c) continuing application of the electron beam to said pattern for a time sufficient and in dose sufficient to form a bound surface compound structure of the reactant fragment and substrate material locally coating the substrate surface in the beam exposure pattern; and (d) etching the substrate surface by a selective means for removing uncoated substrate material preferentially to the removal of said surface compound structure.
Claim 14
Independent Claim 174 words
A method of forming submicron structures by electron beam enhanced surface modification of a substrate, including the steps of: (a) locating a substrate surface within an atmosphere of a partial pressure of a selected gas phase material that is capable of forming as dissociation products a reactant fragment and a stable leaving group when subjected to an electron beam; (b) writing a beam exposure pattern directly on said substrate surface by applying to the surface an electron beam of submicron width through the gas phase to cause dissociation of the gas phase and accumulation of the reactant fragment at the interface of the beam and the substrate surface; (c) continuing application of the electron beam to said pattern for a time sufficient and in dose sufficient to form a bound surface compound structure of the reactant fragment and substrate material locally coating the substrate surface in the beam exposure pattern; and (d) etching the substrate surface by a selective means for removing uncoated substrate material preferentially to the removal of said surface compound structure.
Claim 15
Dependent Claim 116 words
The method of claim 12, wherein said substrate surface is comprised of a first material and is carried on a substrate stack having an underlying body of second material that is capable of being doped to form a semiconductor device, further comprising: (a) exposing a portion of the second material by continuing said selective etching step sufficiently to remove an uncoated portion of the first material; (b) doping said exposed portion of the second material to form a semiconductor device region; and (c) exposing a further portion of the second material by application of an etching means for removing the substrate coating and first material preferentially to removal of the second material from the substrate stack.
Claim 16
Dependent Claim 142 words
The method of claim 13, further comprising, after etching to remove the substrate coating and first material: (a) metalizing the exposed surface of said second material; (b) defining an interconnect line location from the semiconductor device region by writing a beam exposure pattern directly on said metalized surface under a partial pressure of a selected gas phase material capable of dissociating under electron beam exposure to oxygen and a stable gaseous leaving group; (c) continuing beam exposure for a time sufficient and a dose sufficient to form a bound oxide surface compound structure of the metal and oxygen; and (d) defining the interconnect line from the semiconductor device region by etching the metalized surface by a selective means for removing the unoxidized metal coating preferentially to the removal of the oxidized metal and the underlying semiconductor device region in the substrate stack.
Claim 17
Dependent Claim 14 words
The method of claim 13, wherein said second material consists essentially of doped silicon.
Claim 18
Dependent Claim 13 words
The method of claim 14, wherein said metalized surface consists essentially of aluminum.
Claim 19
Dependent Claim 26 words
The method of claim 12, wherein said gas phase is chosen from the group consisting of: carbon dioxide nitrous oxide nitrogen dioxide water vapor and oxygen.
Claim 20
Dependent Claim 38 words
The method of claim 12, wherein said substrate material is chosen from the group consisting of: aluminum, antimony, barium, beryllium, boron, calcium, chromium, iron, magnesium, manganese, molybdenum, silicon, strontium, tantalum, tin, titanium, tungsten, uranium, vanadium, zinc, and zirconium.
Claim 21
Dependent Claim 21 words
The method of claim 18, wherein said substrate material comprises an alloy of an element of the group of claim 18.
Claim 22
Independent Claim 140 words
A method of forming a submicron semiconductor device in a silicon substrate, comprising: (a) locating a silicon substrate in a partial pressure of a gas phase material that dissociates under the energy of an electron beam to yield a dopant dissociation product capable of becoming incorporated into the crystal lattice of the substrate under the energy of an electron beam; (b) applying a first electron beam of a first beam energy and of submicron beam width to a selected location on the substrate surface; and (c) continuing application of said first beam to the selected location for a time sufficient and in a dose sufficient to induce accumulation of the dopant dissociation product at said selected location and to induce incorporation of the dopant dissociation product into the crystal lattice of the substrate to define a submicron semiconductor device region.
Claim 23
Independent Claim 140 words
A method of forming a submicron semiconductor device in a silicon substrate, comprising: (a) locating a silicon substrate in a partial pressure of a gas phase material that dissociates under the energy of an electron beam to yield a dopant dissociation product capable of becoming incorporated into the crystal lattice of the substrate under the energy of an electron beam; (b) applying a first electron beam of a first beam energy and of submicron beam width to a selected location on the substrate surface; and (c) continuing application of said first beam to the selected location for a time sufficient and in a dose sufficient to induce accumulation of the dopant dissociation product at said selected location and to induce incorporation of the dopant dissociation product into the crystal lattice of the substrate to define a submicron semiconductor device region.
Claim 24
Dependent Claim 49 words
The method of claim 19, wherein said gas phase material is of the type capable of thermally diffusing its dopant into the silicon substrate, further comprising cooling the substrate at least during electron beam exposure to reduce thermal diffusion of the gas phase dopant outside the beam exposure area.
Claim 25
Dependent Claim 72 words
The method of claim 20, further comprising simultaneously with application of said first beam, applying a second electron beam of submicron width and of a second beam energy to substantially the same selected location, wherein the first beam energy is adapted to cause dissociation of the gas phase material into at least the dopant, and the second beam energy is adapted to cause diffusion of the dopant into the silicon crystal lattice.
Claim 26
Dependent Claim 185 words
The method of claim 20, further comprising after defining said semiconductor device region: (a) vacuum depositing a metal film over the substrate surface, wherein the metal is capable of forming a stable oxide surface structure; (b) locating said metalized substrate surface in a partial pressure of a gas phase material comprising a gas capable of dissociating under the energy of an electron beam into a stable gaseous leaving group and oxygen; (c) applying an electron beam of submicron width to the metalized surface in a pattern defining an interconnect line from said semiconductor device area; (d) continuing application of the electron beam in said pattern for a time sufficient and in a dose sufficient to cause accumulation of oxygen at the interface of the beam and the metalized surface and to induce formation of a stable oxide surface compound structure in the beam pattern; and (e) defining a residual intrconnect line of said metal film from the semiconductor device region by etching the metalized surface with a selective means for removing uncoated portions of the metal in preference to the coated portions of the metal.
Claim 27
Dependent Claim 30 words
The method of claim 23, further comprising, after definition of the semiconductor device region and interconnect line on the substrate surface, vacuum depositing an epitaxial film over the substrate surface.
Claim 28
Dependent Claim 15 words
The method of claim 24, further comprising depositing a silicon layer on said epitaxial film.

References Cited (Backward Citations)

US4212082A Cited
US4213192A Cited
US4377437A Cited
US4407933A Cited
US4370195A Cited
US4412885A Cited
US4522674A Cited
US4490211A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-01-27 1989-07-29 1990-01-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-01-27 1993-07-29 1994-01-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-01-27 1997-07-29 1998-01-28 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag