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US5683941A Expired / Lapsed US ⏱️ 0.0 years remaining

Self-aligned polycide process that utilizes a planarized layer of material to expose polysilicon structures to a subsequently deposited metal layer that is reacted to form the metal silicide

Assignee: National Semiconductor Corp
•
Filing: 1996-07-02
•
Granted: 1997-11-04
•
Expires: 2016-07-02
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Abstract

Abstract The process for forming a layer of metal silicide over polysilicon structures, such as gates and interconnect lines, is simplified by forming a layer of insulation material over the polysilicon structures, removing the layer of insulation material until the layer of insulation material is substantially planar and the thickness of the insulation material over the polysilicon structures is within a predetermined thickness range, etching the planarized layer of insulation material until portions of the polysilicon structures are exposed, depositing a layer of metal over the resulting structure, and then reacting the metal layer with the polysilicon structures to form the layer of metal silicide.

Inventors

  • 👤 Dah-Bin Kao
  • 👤 John Pierce

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 10:59
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/066; H10D; H10D64/00; H10D64/60; H10D64/66; H10D64/661; H10D64/662; H10D64/663; H10D30/00; H10D30/01; H10D30/021; H10D30/0212; H10D48/00; H10D48/01; H10D48/031; H10D48/032; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01306; H10D64/01308; H10D64/0131; H10D64/01318; H10D64/0132; H10D64/671; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0135; H10D84/0137; H10D84/0165; H10D84/0172; H10D84/0174; H10D84/0177; H10D84/02; H10D84/03; H10D84/038; H10P; H10P50/00; H10P50/20; H10P50/28; H10P95/00; H10W20/071; H10W20/092

Claims Analysis

Total Claims: 78
Claim 1
Independent Claim 130 words
A method for forming a layer of metal silicide over a structure formed as part of a semiconductor device, the method comprising the steps of: forming a layer of insulation material over the semiconductor device such that the structure is covered with the layer of insulation material; removing the layer of insulation material until the layer of insulation material is substantially planar, and a surface of the structure is exposed; depositing a layer of metal over the layer of insulation material and the surface of the structure; reacting the layer of metal with the structure to form a layer of metal silicide over the structure and a layer of unreacted metal over the layer of insulation material; and removing the layer of unreacted metal from the layer of insulation material.
Claim 2
Independent Claim 130 words
A method for forming a layer of metal silicide over a structure formed as part of a semiconductor device, the method comprising the steps of: forming a layer of insulation material over the semiconductor device such that the structure is covered with the layer of insulation material; removing the layer of insulation material until the layer of insulation material is substantially planar, and a surface of the structure is exposed; depositing a layer of metal over the layer of insulation material and the surface of the structure; reacting the layer of metal with the structure to form a layer of metal silicide over the structure and a layer of unreacted metal over the layer of insulation material; and removing the layer of unreacted metal from the layer of insulation material.
Claim 3
Dependent Claim 15 words
The method of claim 1 wherein the structure includes a gate of a MOS transistor.
Claim 4
Dependent Claim 26 words
The method of claim 2 wherein the gate is formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 5
Dependent Claim 22 words
The method of claim 2 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 6
Dependent Claim 24 words
The method of claim 2 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 7
Dependent Claim 15 words
The method of claim 1 wherein the structure includes an emitter of a bipolar transistor.
Claim 8
Dependent Claim 26 words
The method of claim 6 wherein the emitter is formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 9
Dependent Claim 22 words
The method of claim 6 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 10
Dependent Claim 24 words
The method of claim 6 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 11
Dependent Claim 11 words
The method of claim 1 wherein the structure includes an interconnect.
Claim 12
Dependent Claim 26 words
The method of claim 10 wherein the interconnect is formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 13
Dependent Claim 22 words
The method of claim 10 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 14
Dependent Claim 24 words
The method of claim 10 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 15
Dependent Claim 26 words
The method of claim 1 and further comprising the step of: etching the planarized layer of insulation material until sidewall portions of the structure are exposed.
Claim 16
Independent Claim 151 words
A method for forming a layer of metal silicide over a structure formed as part of a semiconductor device, the method comprising the steps of: forming a layer of insulation material over the semiconductor device so that the structure is covered with the layer of insulation material; removing the layer of insulation material until the layer of insulation material is substantially planar, and the thickness of the layer of insulation material over the structure is within a thickness range; etching the planarized layer of insulation material until portions of the structure are exposed; depositing a layer of metal over the layer of insulation material and the exposed structure; reacting the layer of metal with the structure to form a layer of metal silicide over the structure and a layer of unreacted metal over the layer of insulation material; and removing the layer of unreacted metal from the layer of insulation material.
Claim 17
Independent Claim 151 words
A method for forming a layer of metal silicide over a structure formed as part of a semiconductor device, the method comprising the steps of: forming a layer of insulation material over the semiconductor device so that the structure is covered with the layer of insulation material; removing the layer of insulation material until the layer of insulation material is substantially planar, and the thickness of the layer of insulation material over the structure is within a thickness range; etching the planarized layer of insulation material until portions of the structure are exposed; depositing a layer of metal over the layer of insulation material and the exposed structure; reacting the layer of metal with the structure to form a layer of metal silicide over the structure and a layer of unreacted metal over the layer of insulation material; and removing the layer of unreacted metal from the layer of insulation material.
Claim 18
Dependent Claim 15 words
The method of claim 15 wherein the structure includes a gate of a MOS transistor.
Claim 19
Dependent Claim 26 words
The method of claim 16 wherein the gate is formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 20
Dependent Claim 22 words
The method of claim 16 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 21
Dependent Claim 24 words
The method of claim 16 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 22
Dependent Claim 15 words
The method of claim 15 wherein the structure includes an emitter of a bipolar transistor.
Claim 23
Dependent Claim 26 words
The method of claim 20 wherein the emitter is formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 24
Dependent Claim 22 words
The method of claim 20 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 25
Dependent Claim 24 words
The method of claim 20 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 26
Dependent Claim 11 words
The method of claim 15 wherein the structure includes an interconnect.
Claim 27
Dependent Claim 27 words
The method of claim 24 wherein the interconnect line is formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 28
Dependent Claim 22 words
The method of claim 24 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 29
Dependent Claim 24 words
The method of claim 24 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 30
Independent Claim 82 words
A method for forming a layer of metal silicide over a structure formed as part of a semiconductor device, the method comprising the steps of: forming a layer of insulation material over the semiconductor device such that the structure is covered with the layer of insulation material; removing the layer of insulation material until the layer of insulation material is substantially planar, and a surface of the structure is exposed; and selectively chemical vapor depositing a layer of metal over the structure.
Claim 31
Independent Claim 82 words
A method for forming a layer of metal silicide over a structure formed as part of a semiconductor device, the method comprising the steps of: forming a layer of insulation material over the semiconductor device such that the structure is covered with the layer of insulation material; removing the layer of insulation material until the layer of insulation material is substantially planar, and a surface of the structure is exposed; and selectively chemical vapor depositing a layer of metal over the structure.
Claim 32
Dependent Claim 15 words
The method of claim 28 wherein the structure includes a gate of a MOS transistor.
Claim 33
Dependent Claim 26 words
The method of claim 29 wherein the gate is formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 34
Dependent Claim 22 words
The method of claim 29 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 35
Dependent Claim 24 words
The method of claim 29 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 36
Dependent Claim 15 words
The method of claim 28 wherein the structure includes an emitter of a bipolar transistor.
Claim 37
Dependent Claim 26 words
The method of claim 33 wherein the emitter is formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 38
Dependent Claim 22 words
The method of claim 33 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 39
Dependent Claim 24 words
The method of claim 33 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 40
Dependent Claim 11 words
The method of claim 28 wherein the structure includes an interconnect.
Claim 41
Dependent Claim 26 words
The method of claim 37 wherein the interconnect is formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 42
Dependent Claim 22 words
The method of claim 37 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 43
Dependent Claim 24 words
The method of claim 37 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 44
Independent Claim 346 words
A method for forming polycide on a semiconductor device formed in a substrate of a first conductivity type, the device including: a plurality of active device regions; a field oxide region formed in the substrate that isolates the plurality of active device regions, a plurality of spaced-apart doped regions formed in the substrate so that a pair of doped regions is formed in each active device region, the doped regions defining a plurality of substrate channel regions such that each pair of doped regions in an active device region defines a corresponding substrate channel region therebetween, a plurality of gate oxide regions formed over the plurality of substrate channel regions such that each gate oxide region is formed over a corresponding substrate channel region, a plurality of gates formed over the plurality of gate oxide regions such that each gate is formed over a corresponding gate oxide region, each of the gates having sidewalls, an interconnect line formed over the field oxide region, the interconnect line having sidewalls, and a plurality of spacers formed over the sidewalls of the gates, and the sidewalls of the interconnect line, the method comprising the steps of: depositing a layer of insulation material having a thickness over the field oxide region, the substrate, the gates, the interconnect line, and the spacers; removing the layer of insulation material until the layer of insulation material is substantially planar, and a surface of the gates is exposed; etching the layer of insulation material until surfaces of both the gates and the interconnect line are exposed; depositing a layer of metal over the layer of insulation material, the gates, the spacers, and the interconnect line; reacting the layer of metal with the gates and interconnect line to form a layer of metal silicide over the gates and interconnect line, and a layer of unreacted metal over the layer of insulation material and the spacers; and removing the layer of unreacted metal from the layer of insulation material and the spacers, thereby leaving the layer of metal silicide over the gates and the interconnect line.
Claim 45
Independent Claim 346 words
A method for forming polycide on a semiconductor device formed in a substrate of a first conductivity type, the device including: a plurality of active device regions; a field oxide region formed in the substrate that isolates the plurality of active device regions, a plurality of spaced-apart doped regions formed in the substrate so that a pair of doped regions is formed in each active device region, the doped regions defining a plurality of substrate channel regions such that each pair of doped regions in an active device region defines a corresponding substrate channel region therebetween, a plurality of gate oxide regions formed over the plurality of substrate channel regions such that each gate oxide region is formed over a corresponding substrate channel region, a plurality of gates formed over the plurality of gate oxide regions such that each gate is formed over a corresponding gate oxide region, each of the gates having sidewalls, an interconnect line formed over the field oxide region, the interconnect line having sidewalls, and a plurality of spacers formed over the sidewalls of the gates, and the sidewalls of the interconnect line, the method comprising the steps of: depositing a layer of insulation material having a thickness over the field oxide region, the substrate, the gates, the interconnect line, and the spacers; removing the layer of insulation material until the layer of insulation material is substantially planar, and a surface of the gates is exposed; etching the layer of insulation material until surfaces of both the gates and the interconnect line are exposed; depositing a layer of metal over the layer of insulation material, the gates, the spacers, and the interconnect line; reacting the layer of metal with the gates and interconnect line to form a layer of metal silicide over the gates and interconnect line, and a layer of unreacted metal over the layer of insulation material and the spacers; and removing the layer of unreacted metal from the layer of insulation material and the spacers, thereby leaving the layer of metal silicide over the gates and the interconnect line.
Claim 46
Dependent Claim 35 words
The method of claim 41 wherein a first number of the gates are doped to have the first conductivity type, and a second number of the gates are doped to have a second conductivity type.
Claim 47
Dependent Claim 26 words
The method of claim 42 wherein the gates are formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 48
Dependent Claim 22 words
The method of claim 42 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 49
Dependent Claim 24 words
The method of claim 42 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 50
Dependent Claim 16 words
The method of claim 42 wherein the field oxide region includes a trenched field oxide region.
Claim 51
Dependent Claim 19 words
The method of claim 42 wherein the etching step exposes a portion of the sidewalls of the interconnect line.
Claim 52
Dependent Claim 13 words
The method of claim 41 wherein the gates have a single conductivity type.
Claim 53
Dependent Claim 26 words
The method of claim 48 wherein the gates are formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 54
Dependent Claim 22 words
The method of claim 48 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 55
Dependent Claim 24 words
The method of claim 48 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 56
Dependent Claim 16 words
The method of claim 48 wherein the field oxide region includes a trenched field oxide region.
Claim 57
Dependent Claim 19 words
The method of claim 48 wherein the etching step exposes a portion of the sidewalls of the interconnect line.
Claim 58
Dependent Claim 28 words
The method of claim 48 and further comprising the step of doping the gates and the interconnect line prior to the step of depositing the layer of metal.
Claim 59
Independent Claim 337 words
A method for forming polycide on a semiconductor device formed in a substrate of a first conductivity type, the device including: a plurality of active device regions; a field oxide region formed in the substrate that isolates the plurality of active device regions, a plurality of spaced-apart doped regions formed in the substrate so that a pair of doped regions is formed in each active device region, the doped regions defining a plurality of substrate channel regions such that each pair of doped regions in an active device region defines a corresponding substrate channel region therebetween, a plurality of gate oxide regions formed over the plurality of substrate channel regions such that each gate oxide region is formed over a corresponding substrate channel region, a plurality of gates formed over the plurality of gate oxide regions such that each gate is formed over a corresponding gate oxide region, an interconnect line formed over the field oxide region, the interconnect line having sidewalls, and a plurality of spacers formed over the sidewalls of the gates, and the sidewalls of the interconnect line, the method comprising the steps of: depositing a layer of insulation material having a thickness over the field oxide region, the substrate, the gates, the interconnect line, and the spacers; removing the layer of insulation material, a portion of the gates, and a portion of the spacers formed over the sidewalls of the gates until the layer of insulation material is substantially planar, and the top surfaces of the gates and the interconnect line are exposed; depositing a layer of metal over the layer of insulation material, the spacers, the gates, and the interconnect line; reacting the layer of metal with the gates and the interconnect line to form a layer of metal silicide over the gates and interconnect line, and a layer of unreacted metal over the layer of insulation material and the spacers; and removing the layer of unreacted metal, thereby leaving the layer of metal silicide over the gates and the interconnect line.
Claim 60
Independent Claim 337 words
A method for forming polycide on a semiconductor device formed in a substrate of a first conductivity type, the device including: a plurality of active device regions; a field oxide region formed in the substrate that isolates the plurality of active device regions, a plurality of spaced-apart doped regions formed in the substrate so that a pair of doped regions is formed in each active device region, the doped regions defining a plurality of substrate channel regions such that each pair of doped regions in an active device region defines a corresponding substrate channel region therebetween, a plurality of gate oxide regions formed over the plurality of substrate channel regions such that each gate oxide region is formed over a corresponding substrate channel region, a plurality of gates formed over the plurality of gate oxide regions such that each gate is formed over a corresponding gate oxide region, an interconnect line formed over the field oxide region, the interconnect line having sidewalls, and a plurality of spacers formed over the sidewalls of the gates, and the sidewalls of the interconnect line, the method comprising the steps of: depositing a layer of insulation material having a thickness over the field oxide region, the substrate, the gates, the interconnect line, and the spacers; removing the layer of insulation material, a portion of the gates, and a portion of the spacers formed over the sidewalls of the gates until the layer of insulation material is substantially planar, and the top surfaces of the gates and the interconnect line are exposed; depositing a layer of metal over the layer of insulation material, the spacers, the gates, and the interconnect line; reacting the layer of metal with the gates and the interconnect line to form a layer of metal silicide over the gates and interconnect line, and a layer of unreacted metal over the layer of insulation material and the spacers; and removing the layer of unreacted metal, thereby leaving the layer of metal silicide over the gates and the interconnect line.
Claim 61
Dependent Claim 31 words
The method of claim 55 and further including the step of etching the layer of insulation material and the spacers to expose the sidewalls of the gates and the interconnect line.
Claim 62
Independent Claim 346 words
A method for forming polycide on a semiconductor device formed in a substrate of a first conductivity type, the device including: a plurality of active device regions; a field oxide region formed in the substrate that isolates the plurality of active device regions, a plurality of spaced-apart doped regions formed in the substrate so that a pair of doped regions is formed in each active device region, the doped regions defining a plurality of substrate channel regions such that each pair of doped regions in an active device region defines a corresponding substrate channel region therebetween, a plurality of gate oxide regions formed over the plurality of substrate channel regions such that each gate oxide region is formed over a corresponding substrate channel region, a plurality of gates formed over the plurality of gate oxide regions such that each gate is formed over a corresponding gate oxide region, each of the gates having sidewalls, an interconnect line formed over the field oxide region, the interconnect line having sidewalls, and a plurality of spacers formed over the sidewalls of the gates, and the sidewalls of the interconnect line, the method comprising the steps of: depositing a layer of insulation material having a thickness over the field oxide region, the substrate, the gates, the interconnect line, and the spacers; removing the layer of insulation material until the layer of insulation material is substantially planar, and the thickness of the layer of insulation material over the gates is within a thickness range; etching the layer of insulation material until surfaces of both the gates and the interconnect line are exposed; depositing a layer of metal over the layer of insulation material, the gates, the spacers, and the interconnect line; reacting the layer of metal with the gates and interconnect line to form a layer of metal silicide over the gates and interconnect line, and a layer of unreacted metal over the layer of insulation material and the spacers; and removing the layer of unreacted metal, thereby leaving the layer of metal silicide over the gates and the interconnect line.
Claim 63
Independent Claim 346 words
A method for forming polycide on a semiconductor device formed in a substrate of a first conductivity type, the device including: a plurality of active device regions; a field oxide region formed in the substrate that isolates the plurality of active device regions, a plurality of spaced-apart doped regions formed in the substrate so that a pair of doped regions is formed in each active device region, the doped regions defining a plurality of substrate channel regions such that each pair of doped regions in an active device region defines a corresponding substrate channel region therebetween, a plurality of gate oxide regions formed over the plurality of substrate channel regions such that each gate oxide region is formed over a corresponding substrate channel region, a plurality of gates formed over the plurality of gate oxide regions such that each gate is formed over a corresponding gate oxide region, each of the gates having sidewalls, an interconnect line formed over the field oxide region, the interconnect line having sidewalls, and a plurality of spacers formed over the sidewalls of the gates, and the sidewalls of the interconnect line, the method comprising the steps of: depositing a layer of insulation material having a thickness over the field oxide region, the substrate, the gates, the interconnect line, and the spacers; removing the layer of insulation material until the layer of insulation material is substantially planar, and the thickness of the layer of insulation material over the gates is within a thickness range; etching the layer of insulation material until surfaces of both the gates and the interconnect line are exposed; depositing a layer of metal over the layer of insulation material, the gates, the spacers, and the interconnect line; reacting the layer of metal with the gates and interconnect line to form a layer of metal silicide over the gates and interconnect line, and a layer of unreacted metal over the layer of insulation material and the spacers; and removing the layer of unreacted metal, thereby leaving the layer of metal silicide over the gates and the interconnect line.
Claim 64
Dependent Claim 35 words
The method of claim 57 wherein a first number of the gates are doped to have the first conductivity type, and a second number of the gates are doped to have a second conductivity type.
Claim 65
Dependent Claim 26 words
The method of claim 58 wherein the gates are formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 66
Dependent Claim 22 words
The method of claim 58 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 67
Dependent Claim 24 words
The method of claim 58 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 68
Dependent Claim 16 words
The method of claim 58 wherein the field oxide region includes a trenched field oxide region.
Claim 69
Dependent Claim 19 words
The method of claim 58 wherein the etching step exposes a portion of the sidewalls of the interconnect line.
Claim 70
Dependent Claim 13 words
The method of claim 58 wherein the gates have a single conductivity type.
Claim 71
Dependent Claim 26 words
The method of claim 64 wherein the gates are formed from a material selected from the group consisting of polysilicon, amorphous silicon, and polycrystalline silicon germanium.
Claim 72
Dependent Claim 22 words
The method of claim 64 wherein the layer of metal is selected from the group consisting of tungsten, titanium, nickel, and cobalt.
Claim 73
Dependent Claim 24 words
The method of claim 64 wherein the layer of insulation material is selected from the group consisting of oxide, nitride, and an oxide/nitride composite.
Claim 74
Dependent Claim 16 words
The method of claim 64 wherein the field oxide region includes a trenched field oxide region.
Claim 75
Dependent Claim 19 words
The method of claim 64 wherein the etching step exposes a portion of the sidewalls of the interconnect line.
Claim 76
Dependent Claim 28 words
The method of claim 64 and further comprising the step of doping the gates and the interconnect line prior to the step of depositing the layer of metal.
Claim 77
Independent Claim 205 words
A method for forming polycide on a semiconductor device formed in a substrate of a first conductivity type, the device including: spaced-apart doped regions formed in the substrate, the doped regions defining a substrate channel region therebetween, a gate oxide region formed over the substrate channel region, a gate formed over the gate oxide region, the gate having sidewalls, and a spacer formed over the sidewalls of the gate, the method comprising the steps of: depositing a layer of insulation material having a thickness over the substrate, the gate, and the spacer; removing the layer of insulation material until the layer of insulation material is substantially planar, and the thickness of the layer of insulation material over the gate is within a thickness range; etching the layer of insulation material until a surface of the gate is exposed; depositing a layer of metal over the layer of insulation material and the gate; reacting the layer of metal with the gate to form a layer of metal silicide over the gate, and a layer of unreacted metal over the layer of insulation material; and removing the layer of unreacted metal from the layer of insulation material, thereby leaving the layer of metal silicide over the gate.
Claim 78
Independent Claim 205 words
A method for forming polycide on a semiconductor device formed in a substrate of a first conductivity type, the device including: spaced-apart doped regions formed in the substrate, the doped regions defining a substrate channel region therebetween, a gate oxide region formed over the substrate channel region, a gate formed over the gate oxide region, the gate having sidewalls, and a spacer formed over the sidewalls of the gate, the method comprising the steps of: depositing a layer of insulation material having a thickness over the substrate, the gate, and the spacer; removing the layer of insulation material until the layer of insulation material is substantially planar, and the thickness of the layer of insulation material over the gate is within a thickness range; etching the layer of insulation material until a surface of the gate is exposed; depositing a layer of metal over the layer of insulation material and the gate; reacting the layer of metal with the gate to form a layer of metal silicide over the gate, and a layer of unreacted metal over the layer of insulation material; and removing the layer of unreacted metal from the layer of insulation material, thereby leaving the layer of metal silicide over the gate.

References Cited (Backward Citations)

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