Device improvement by lowering LDD resistance with new silicide process
First Claim
Patent Images
1. A method for fabricating a semiconductor device on a structure, the method comprising:
- forming a dielectric layer adjacent a gate conductor of the semiconductor device and above an LDD region of the structure;
removing a first portion of the dielectric layer above the gate conductor and above the LDD region;
forming a first conductive layer above the gate conductor, adjacent the dielectric layer and above the LDD region; and
saliciding the first conductive layer above the gate conductor and above the LDD region to form a salicided first conductive layer.
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Abstract
A method is provided for fabricating a semiconductor device on a structure, the method including forming a dielectric layer adjacent a gate conductor of the semiconductor device and above an LDD region of the structure and removing a first portion of the dielectric layer above the gate conductor and above the LDD region. The method also includes forming a first conductive layer above the gate conductor, adjacent the dielectric layer and above the LDD region and saliciding the first conductive layer above the gate conductor and above the LDD region to form a salicided first conductive layer.
29 Citations
40 Claims
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1. A method for fabricating a semiconductor device on a structure, the method comprising:
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forming a dielectric layer adjacent a gate conductor of the semiconductor device and above an LDD region of the structure;
removing a first portion of the dielectric layer above the gate conductor and above the LDD region;
forming a first conductive layer above the gate conductor, adjacent the dielectric layer and above the LDD region; and
saliciding the first conductive layer above the gate conductor and above the LDD region to form a salicided first conductive layer. - View Dependent Claims (2, 3, 4, 5)
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6. A method for fabricating a MOSFET on a substrate, the method comprising:
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forming a dielectric layer adjacent a gate conductor of the MOSFET and above LDD regions of the substrate;
removing a first portion of the dielectric layer above the gate conductor and above the LDD regions;
forming a first conductive layer above the gate conductor, adjacent the dielectric layer and above the LDD regions;
saliciding the first conductive layer above the gate conductor and above the LDD regions to form a salicided first conductive layer;
forming dielectric spacers adjacent a second portion the dielectric layer adjacent the gate conductor;
introducing a dopant into source/drain regions of the substrate;
forming a second conductive layer adjacent the dielectric spacers and above the salicided first conductive layer above the gate conductor and above the source/drain regions; and
saliciding the second conductive layer above the gate conductor and above the source/drain regions to form a salicided second conductive layer. - View Dependent Claims (7, 8, 9, 10)
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11. A method for fabricating a MOSFET on a substrate, the method comprising:
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depositing a dielectric layer adjacent a gate conductor and gate dielectric of the MOSFET and above LDD regions of the substrate;
etching away a first portion of the dielectric layer above the gate conductor and above the LDD regions;
depositing a first conductive layer above the gate conductor, adjacent the dielectric layer and above the LDD regions;
annealing the first conductive layer above the gate conductor and above the LDD regions to form a salicided first conductive layer;
forming dielectric spacers adjacent a second portion the dielectric layer adjacent the gate conductor and the gate dielectric;
implanting a dopant into source/drain regions of the substrate;
depositing a second conductive layer adjacent the dielectric spacers and above the salicided first conductive layer above the gate conductor and above the source/drain regions; and
annealing the second conductive layer above the gate conductor and above the source/drain regions to form a salicided second conductive layer. - View Dependent Claims (12, 13, 14, 15, 17, 18, 19, 20)
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16. A method for fabricating a MOSFET on a substrate, the method comprising:
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depositing a dielectric layer adjacent a gate conductor and gate dielectric of the MOSFET and above LDD regions of the substrate, the dielectric layer having a thickness in a range of about 50 Å
-300 Å and
the LDD regions having been implanted with an LDD dose of one of arsenic and boron difluoride and subjected to a rapid thermal anneal process performed at a temperature ranging from approximately 800-1100°
C. for a time ranging from approximately 5-60 seconds, the LDD dose ranging from about 1.0×
1014-1.0×
1015 ions/cm2 at an implant energy ranging from about 3-50 keV;
etching away a First portion of the dielectric layer above the gate conductor and above the LDD regions using anisotropic reactive ion etching;
depositing a first conductive layer above the gate conductor, adjacent the dielectric layer and above the LDD regions, the first conductive layer having a thickness in a range of about 50 Å
-150 Å
;
annealing the first conductive layer above the gate conductor and above the LDD regions to form a salicided first conductive layer, the first conductive layer being subjected to a rapid thermal anneal process performed at a temperature ranging from approximately 450-800°
C. for a time ranging from approximately 15-60 seconds, a distance between the salicided first conductive layer and a junction between the LDD regions and the substrate being in a range of at least about 50 Å
-200 Å
;
forming dielectric spacers adjacent a second portion the dielectric layer adjacent the gate conductor and the gate dielectric, the dielectric spacers having a base thickness in a range of about 300 Å
-1500 Å
;
implanting one of phosphorus and boron into source/drain regions of the substrate, a dose of the one of phosphorus and boron ranging from about 1.0×
1015-5.0×
1015 ions/cm2 at an implant energy ranging from about 30-100 keV;
depositing a second conductive layer adjacent the dielectric spacers and above the salicided first conductive layer above the gate conductor and above the source/drain regions, the second conductive layer having a thickness in a range of about 100 Å
-400 Å
; and
annealing the second conductive layer above the gate conductor and above the source/drain regions to form a salicided second conductive layer, the second conductive layer being subjected to an initial rapid thermal anneal process performed at a temperature ranging from approximately 450-800°
C. for a time ranging from approximately 15-60 seconds, the second conductive layer being subjected to wet chemical strip to remove unsilicided portions of the second conductive layer, the second conductive layer being subjected to a final rapid thermal anneal process performed at a temperature ranging from approximately 800-1000°
C. for a time ranging from approximately 10-60 seconds, a distance between the salicided second conductive layer and a junction between the source/drain regions and the substrate being in a range of at least about 50 Å
-200 Å
.
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21. A semiconductor device comprising:
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a structure;
a gate dielectric above the structure;
a gate conductor above the gate dielectric;
an LDD region of the structure adjacent the gate dielectric and the gate conductor;
a dielectric layer adjacent the gate conductor and the gate dielectric; and
a salicided first conductive layer above the gate conductor and above the LDD region. - View Dependent Claims (22, 23, 24, 25, 27, 28, 29, 30)
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26. A MOSFET comprising:
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a substrate;
a gate dielectric above the substrate;
a gate conductor above the gate dielectric;
LDD regions of the substrate adjacent the gate dielectric and the gate conductor;
a dielectric layer adjacent the gate conductor and the gate dielectric;
a salicided first conductive layer above the gate conductor and above the LDD regions;
dielectric spacers adjacent the dielectric layer adjacent the gate conductor;
source/drain regions of the substrate adjacent the dielectric spacers; and
a salicided second conductive layer above the gate conductor and above the source/drain regions.
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31. A MOSFET on a substrate formed by a method comprising:
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depositing a dielectric layer adjacent a gate conductor and gate dielectric of the MOSFET and above LDD regions of the substrate;
etching away a first portion of the dielectric layer above the gate conductor and above the LDD regions;
depositing a first conductive layer above the gate conductor, adjacent the dielectric layer and above the LDD regions;
annealing the first conductive layer above the gate conductor and above the LDD regions to form a salicided first conductive layer;
forming dielectric spacers adjacent a second portion the dielectric layer adjacent the gate conductor and the gate dielectric;
implanting a dopant into source/drain regions of the substrate;
depositing a second conductive layer adjacent the dielectric spacers and above the salicided first conductive layer above the gate conductor and above the source/drain regions; and
annealing the second conductive layer above the gate conductor and above the source/drain regions to form a salicided second conductive layer. - View Dependent Claims (32, 33, 34, 35, 37, 38, 39, 40)
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36. A MOSFET on a substrate formed by a method comprising:
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depositing a dielectric layer adjacent a gate conductor and gate dielectric of the MOSFET and above LDD regions of the substrate, the dielectric layer having a thickness in a range of about 50 Å
-300 Å and
the LDD regions having been implanted with an LDD dose of one of arsenic and boron difluoride and subjected to a rapid thermal anneal process performed at a temperature ranging from approximately 800-1100°
C. for a time ranging from approximately 5-60 seconds, the LDD dose ranging from about 1.0×
1014-1.0×
1015 ions/cm2 at an implant energy ranging from about 3-50 keV;
etching away a first portion of the dielectric layer above the gate conductor and above the LDD regions using anisotropic reactive ion etching;
depositing a first conductive layer above the gate conductor, adjacent the dielectric layer and above the LDD regions. the first conductive layer having a thickness in a range of about 50 Å
-150 Å
;
annealing the first conductive layer above the gate conductor and above the LDD regions to form a salicided first conductive layer, the first conductive layer being subjected to a rapid thermal anneal process performed at a temperature ranging from approximately 450-800°
C. for a time ranging from approximately 15-60 seconds, a distance between the salicided first conductive layer and a junction between the LDD regions and the substrate being in a range of at least about 50 Å
-200 Å
;
forming dielectric spacers adjacent a second portion the dielectric layer adjacent the gate conductor and the gate dielectric, the dielectric spacers having a base thickness in a range of about 300 Å
-1500 Å
;
implanting one of phosphorus and boron into source/drain regions of the substrate, a dose of the one of phosphorus and boron ranging from about 1.0×
1015-5.0×
1015 ions/cm2 at an implant energy ranging from about 30-100 keV;
depositing a second conductive layer adjacent the dielectric spacers and above the salicided first conductive layer above the gate conductor and above the source/drain regions, the second conductive layer having a thickness in a range of about 100 Å
-400 Å
; and
annealing the second conductive layer above the gate conductor and above the source/drain regions to form a salicided second conductive layer, the second conductive layer being subjected to an initial rapid thermal anneal process performed at a temperature ranging from approximately 450-800°
C. for a time ranging from approximately 15-60 seconds, the second conductive layer being subjected to wet chemical strip to remove unsilicided portions of the second conductive layer, the second conductive layer being subjected to a final rapid thermal anneal process performed at a temperature ranging from approximately 800-1000°
C. for a time ranging from approximately 10-60 seconds, a distance between the salicided second conductive layer and a junction between the source/drain regions and the substrate being in a range of at least about 50 Å
-200 Å
.
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Specification