Patent US6180470B1 successfully refreshed from Google Patents.
US6180470B1
Expired / Lapsed
US
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FETs having lightly doped drain regions that are shaped with counter and noncounter dorant elements
Assignee: Avery Dennison Corp
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Filing: 1996-12-19
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Granted: 2001-01-30
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Expires: 2016-12-19
Abstract
Abstract Lifetime of a short-channel NMOS device is increased by modifying distributions of electrically active LDD dopant at boundaries of the device's LDD regions. The LDD dopant distributions are modified by implanting counter-dopants at the boundaries of the LDD regions. Group III counter-dopants such as boron and group IV elements such as silicon alter activation properties of the LDD dopant. The dopant distributions are modified at the device's n-junctions to reduce the maximum electric field displacement at an interface defined by the device's gate and substrate. The dopant distributions can be further modified to shape the n-junctions such that hot carriers are injected away from the gate.
Inventors
- 👤 Sheldon Aronowitz
- 👤 Laique Khan
- 👤 James Kimball
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:02
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D30/60; H10D30/601; H10P30/21; H10P30/212; H10P30/225; H10D62/00; H10D62/10; H10D62/17; H10D62/213; H10D62/221; H10D62/235; H10D62/299; H10D62/307; H10D62/351; H10D62/357; H10D62/364; H10D62/371; H10P30/222; Y; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/925
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
92 words
A method of forming an LDD region in a substrate of a FET, the substrate having a crystal lattice structure, the method comprising the steps of: implanting an LDD dopant into the substrate at the boundaries of the LDD region; implanting a counter-dopant into the substrate in a manner that a peak concentration of the counter-dopant is at the boundaries of the LDD region that lie within the substrate, the counter-dopant occupying openings in the lattice structure more readily than the LDD dopant when the substrate is annealed; and annealing the substrate.
Claim 2
Independent Claim
92 words
A method of forming an LDD region in a substrate of a FET, the substrate having a crystal lattice structure, the method comprising the steps of: implanting an LDD dopant into the substrate at the boundaries of the LDD region; implanting a counter-dopant into the substrate in a manner that a peak concentration of the counter-dopant is at the boundaries of the LDD region that lie within the substrate, the counter-dopant occupying openings in the lattice structure more readily than the LDD dopant when the substrate is annealed; and annealing the substrate.
Claim 3
Dependent Claim
22 words
The method of claim 1 , wherein the FET is an NMOS device, and wherein the counter-dopant is a group III element.
Claim 4
Dependent Claim
22 words
The method of claim 1 , wherein the FET is a PMOS device, and wherein the counter-dopant is a group V element.
Claim 5
Dependent Claim
40 words
The method of claim 1 , wherein the FET is a CMOS device including PMOS and NMOS transistors, and wherein the counter-dopant is a group V element for the PMOS transistors and a group III element for the NMOS transistors.
Claim 6
Dependent Claim
35 words
The method of claim 1 , wherein the FET is a CMOS device including PMOS and NMOS transistors, and wherein the counter-dopant is a group IV element for the PMOS transistors and the NMOS transistors.
Claim 7
Dependent Claim
15 words
The method of claim 1 , wherein the LDD dopant is implanted before the counter-dopant.
Claim 8
Dependent Claim
15 words
The method of claim 1 , wherein the LDD dopant is implanted after the counter-dopant.
Claim 9
Dependent Claim
37 words
The method of claim 1 , wherein the FET includes a channel, one end of the channel and the LDD region defining a junction, and wherein the counter-dopant is implanted such that the junction is not abrupt.
Claim 10
Dependent Claim
24 words
The method of claim 8 , wherein an angle implant of at least 45 degrees is used to implant the counter-dopant at the junction.
Claim 11
Dependent Claim
38 words
The method of claim 9 , wherein the FET includes a gate, the gate and the substrate defining a gate/substrate interface, and wherein the junction is shaped such that hot carriers are injected away from the gate/substrate interface.
Claim 12
Dependent Claim
20 words
The method of claim 10 , wherein the counter-dopant is implanted at the junction at different implant angles and energies.
Claim 13
Dependent Claim
19 words
The method of claim 1 , wherein the counter-dopant is also implanted beyond the boundaries of the LDD region.
Claim 14
Independent Claim
85 words
A method of forming a doped region in a semiconductor substrate having a crystalline lattice structure, the method comprising the steps of: implanting a dopant into the substrate within boundaries of the doped region; implanting a counter-dopant into the substrate in a manner that a peak concentration of the counter-dopant is at the boundaries of the doped region that lie within the substrate, the counter-dopant occupying openings in the lattice structure more readily than the dopant when the substrate is annealed; and annealing the substrate.
Claim 15
Independent Claim
85 words
A method of forming a doped region in a semiconductor substrate having a crystalline lattice structure, the method comprising the steps of: implanting a dopant into the substrate within boundaries of the doped region; implanting a counter-dopant into the substrate in a manner that a peak concentration of the counter-dopant is at the boundaries of the doped region that lie within the substrate, the counter-dopant occupying openings in the lattice structure more readily than the dopant when the substrate is annealed; and annealing the substrate.
Claim 16
Dependent Claim
23 words
The method of claim 13 , wherein the dopant is a group V element, and wherein the counter-dopant is a group III element.
Claim 17
Dependent Claim
23 words
The method of claim 13 , wherein the dopant is a group III element, and wherein the counter-dopant is a group V element.
Claim 18
Dependent Claim
14 words
The method of claim 13 , wherein the dopant is implanted before the counter-dopant.
Claim 19
Dependent Claim
14 words
The method of claim 13 , wherein the dopant is implanted after the counter-dopant.
Claim 20
Independent Claim
119 words
A method of fabricating an MOS device, the method comprising the steps of: forming a gate structure on a substrate; implanting an LDD dopant into the substrate on opposite sides of the gate structure; implanting a counter-dopant into the substrate on opposite sides of the gate structure, regions, wherein a peak concentration of the counter-dopant is at depths that define the respective boundaries of the LDD regions that lie within the substrate, the counter-dopant occupying openings in the substrate's lattice structure more readily than the LDD dopant when the substrate is annealed; forming source and drain regions contiguous with the LDD regions; and annealing the substrate, forming at least one level of contacts for the source and drain regions.
Claim 21
Independent Claim
119 words
A method of fabricating an MOS device, the method comprising the steps of: forming a gate structure on a substrate; implanting an LDD dopant into the substrate on opposite sides of the gate structure; implanting a counter-dopant into the substrate on opposite sides of the gate structure, regions, wherein a peak concentration of the counter-dopant is at depths that define the respective boundaries of the LDD regions that lie within the substrate, the counter-dopant occupying openings in the substrate's lattice structure more readily than the LDD dopant when the substrate is annealed; forming source and drain regions contiguous with the LDD regions; and annealing the substrate, forming at least one level of contacts for the source and drain regions.
Claim 22
Dependent Claim
15 words
The method of claim 18 , wherein the LDD dopant is implanted before the counter-dopant.
Claim 23
Dependent Claim
15 words
The method of claim 18 , wherein the LDD dopant is implanted after the counter-dopant.
Claim 24
Dependent Claim
41 words
The method of claim 18 , wherein the LDD regions define a channel therebetween, a junction being defined by an end of the channel and an LDD region, and wherein the counter-dopant is implanted such that the junctions are not abrupt.
Claim 25
Dependent Claim
24 words
The method of claim 21 , wherein an angle implant of at least 45 degrees is used to implant the counter-dopant at the junction.
Claim 26
Dependent Claim
29 words
The method of claim 21 , wherein the junctions are shaped such that hot carriers are injected away from an interface defined by the gate structure and the substrate.
Claim 27
Dependent Claim
20 words
The method of claim 23 , wherein the counter-dopant is implanted at the junctions at different implant angles and energies.
Claim 28
Independent Claim
95 words
A method of forming an LDD region in a substrate of a FET, the substrate having a crystal lattice structure, the method comprising the steps of: implanting an LDD dopant into the substrate within boundaries of the LDD region; implanting a Group IV element into the substrate in a manner that a peak concentration of the counter-dopant is at the boundaries of the LDD region that lie within the substrate, the Group IV element occupying openings in the lattice structure more readily than the LDD dopant when the substrate is annealed; and annealing the substrate.
Claim 29
Independent Claim
95 words
A method of forming an LDD region in a substrate of a FET, the substrate having a crystal lattice structure, the method comprising the steps of: implanting an LDD dopant into the substrate within boundaries of the LDD region; implanting a Group IV element into the substrate in a manner that a peak concentration of the counter-dopant is at the boundaries of the LDD region that lie within the substrate, the Group IV element occupying openings in the lattice structure more readily than the LDD dopant when the substrate is annealed; and annealing the substrate.
Claim 30
Dependent Claim
17 words
The method of claim 25 , wherein the LDD dopant is implanted before the Group IV element.
Claim 31
Dependent Claim
17 words
The method of claim 25 , wherein the LDD dopant is implanted after the Group IV element.
Claim 32
Dependent Claim
39 words
The method of claim 25 , wherein the FET includes a channel, one end of the channel and the LDD region defining a junction, and wherein the Group IV element is implanted such that the junction is not abrupt.
Claim 33
Dependent Claim
24 words
The method of claim 28 , wherein an angle implant of at least 45 degrees is used to implant the counter-dopant at the junction.
Claim 34
Dependent Claim
38 words
The method of claim 29 , wherein the FET includes a gate, the gate and the substrate defining a gate/substrate interface, and wherein the junction is shaped such that hot carriers are injected away from the gate/substrate interface.
Claim 35
Dependent Claim
22 words
The method of claim 30 , wherein the Group IV element is implanted at the junction at different implant angles and energies.
Claim 36
Dependent Claim
21 words
The method of claim 25 , wherein the Group IV element is also implanted beyond the boundaries of the LDD region.
Claim 37
Independent Claim
89 words
A method of forming a doped region in a semiconductor substrate having a crystalline lattice structure, the method comprising the steps of: implanting a dopant into the substrate within boundaries of the doped region; implanting a Group IV element into the substrate in a manner that a peak concentration of the counter-dopant is at the boundaries of the doped region that lie within the substrate, the Group IV element occupying openings in the lattice structure more readily than the dopant when the substrate is annealed; and annealing the substrate.
Claim 38
Independent Claim
89 words
A method of forming a doped region in a semiconductor substrate having a crystalline lattice structure, the method comprising the steps of: implanting a dopant into the substrate within boundaries of the doped region; implanting a Group IV element into the substrate in a manner that a peak concentration of the counter-dopant is at the boundaries of the doped region that lie within the substrate, the Group IV element occupying openings in the lattice structure more readily than the dopant when the substrate is annealed; and annealing the substrate.
Claim 39
Dependent Claim
16 words
The method of claim 33 , wherein the dopant is implanted before the Group IV element.
Claim 40
Dependent Claim
16 words
The method of claim 33 , wherein the dopant is implanted after the Group IV element.
Claim 41
Independent Claim
124 words
A method of fabricating an MOS device, the method comprising the steps of: forming a gate structure on a substrate; implanting an LDD dopant into the substrate on opposite sides of the gate structure; implanting a Group IV element into the substrate on opposite sides of the gate structure, wherein a peak concentration of the Group IV element is at depths that define the respective boundaries of the LDD regions that lie within the substrate, the Group IV element occupying openings in the substrate's lattice structure, more readily than the LDD dopant when the substrate is annealed; forming source and drain regions contiguous with the LDD regions; and annealing the substrate, forming at least one level of contacts for the source and drain regions.
Claim 42
Independent Claim
124 words
A method of fabricating an MOS device, the method comprising the steps of: forming a gate structure on a substrate; implanting an LDD dopant into the substrate on opposite sides of the gate structure; implanting a Group IV element into the substrate on opposite sides of the gate structure, wherein a peak concentration of the Group IV element is at depths that define the respective boundaries of the LDD regions that lie within the substrate, the Group IV element occupying openings in the substrate's lattice structure, more readily than the LDD dopant when the substrate is annealed; forming source and drain regions contiguous with the LDD regions; and annealing the substrate, forming at least one level of contacts for the source and drain regions.
Claim 43
Dependent Claim
17 words
The method of claim 36 , wherein the LDD dopant is implanted before the Group IV element.
Claim 44
Dependent Claim
17 words
The method of claim 37 , wherein the LDD dopant is implanted after the Group IV element.
Claim 45
Dependent Claim
43 words
The method of claim 37 , wherein the LDD regions define a channel therebetween, a junction being defined by an end of the channel and an LDD region, and wherein the Group IV element is implanted such that the junctions are not abrupt.
Claim 46
Dependent Claim
24 words
The method of claim 39 , wherein an angle implant of at least 45 degrees is used to implant the counter-dopant at the junction.
Claim 47
Dependent Claim
29 words
The method of claim 39 , wherein the junctions are shaped such that hot carriers are injected away from an interface defined by the gate structure and the substrate.
Claim 48
Dependent Claim
22 words
The method of claim 41 , wherein the Group IV element is implanted at the junctions at different implant angles and energies.
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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) | 2004-01-30 | 2004-07-31 | 2005-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-01-30 | 2008-07-31 | 2009-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-01-30 | 2012-07-31 | 2013-01-30 | $7700.00 | Window Closed / Lapsed |