US5719425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiple implant lightly doped drain (MILDD) field effect transistor
Assignee: Micron Technology Inc
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Filing: 1996-01-31
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Granted: 1998-02-17
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Expires: 2016-01-31
Abstract
Abstract A multiple implant lightly doped drain ("MILDD") field effect transistor is disclosed. The transistor includes a channel, a gate, a dielectric structure that separates the gate from the channel, a source region and a drain region. The drain region has a first drain subregion, a second drain subregion and a third drain subregion. Each drain subregion has a dopant concentration that differs from that of the other two drain subregions. A method of forming the same is also disclosed.
Inventors
- 👤 Salman Akram
- 👤 Akram Ditali
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:52
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D30/0221; H10D30/60; H10D30/601; H10D30/603; H10D62/00; H10D62/10; H10D62/17; H10D62/351; H10D62/357; H10D62/364; H10D62/371; H10D64/00; H10D64/01; H10D64/021; Y; Y10; Y10S; Y10S257/00; Y10S257/90; Y10S257/929
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
198 words
A structure for forming a transistor on a semiconductor substrate comprising: a channel; a gate; a dielectric structure that separates the gate from the channel, said gate having first and second vertical sides perpendicular to the dielectric structure; a first vertical spacer positioned adjacent to the first vertical side of the gate; a second vertical spacer positioned adjacent to the first vertical spacer; a first contact region; a second contact region having a first subregion, a second subregion and a third subregion, each subregion having a dopant concentration that differs from that of the other two subregions, the channel separating the first contact region from the second contact region, the first subregion being closer to the channel than the second and third subregions, and the second subregion being closer to the channel than the third subregion; wherein each subregion has a depth and the depth of the first subregion is less than the depth of the second subregion and greater than the depth of the third subregion; and wherein the first vertical spacer is generally aligned with a boundary of the second subregion, and the second vertical spacer is generally aligned with a boundary of the third subregion.
Claim 2
Dependent Claim
198 words
A structure for forming a transistor on a semiconductor substrate comprising: a channel; a gate; a dielectric structure that separates the gate from the channel, said gate having first and second vertical sides perpendicular to the dielectric structure; a first vertical spacer positioned adjacent to the first vertical side of the gate; a second vertical spacer positioned adjacent to the first vertical spacer; a first contact region; a second contact region having a first subregion, a second subregion and a third subregion, each subregion having a dopant concentration that differs from that of the other two subregions, the channel separating the first contact region from the second contact region, the first subregion being closer to the channel than the second and third subregions, and the second subregion being closer to the channel than the third subregion; wherein each subregion has a depth and the depth of the first subregion is less than the depth of the second subregion and greater than the depth of the third subregion; and wherein the first vertical spacer is generally aligned with a boundary of the second subregion, and the second vertical spacer is generally aligned with a boundary of the third subregion.
Claim 3
Dependent Claim
33 words
The transistor of claim 1 wherein the first subregion is closer to the channel than the second and third subregions and the second subregion is closer to the channel than the third subregion.
Claim 4
Dependent Claim
25 words
The transistor of claim 2 wherein the dopant concentration of the first subregion is less than the dopant concentrations of the second and third subregions.
Claim 5
Dependent Claim
23 words
The transistor of claim 3 wherein the dopant concentration of the second subregion is less than the dopant concentration of the third subregion.
Claim 6
Dependent Claim
20 words
The transistor of claim 2 wherein each subregion has a depth and the depth of each subregion is substantially similar.
Claim 7
Dependent Claim
29 words
The transistor of claim 2 wherein each subregion has a depth and the depth of the first subregion is less than the depths of the second and third subregions.
Claim 8
Dependent Claim
21 words
The transistor of claim 6 wherein the depth of the second subregion is less than the depth of the third subregion.
Claim 9
Dependent Claim
33 words
The transistor of claim 1 wherein the second contact region further comprises a fourth subregion, the fourth subregion having a dopant concentration that differs from that of the first, second and third subregions.
Claim 10
Dependent Claim
12 words
The transistor of claim 1 wherein the transistor is an N-channel device.
Claim 11
Dependent Claim
36 words
The transistor of claim 1 wherein the first contact region comprises: a first subregion, a second subregion, and a third subregion, each subregion having a dopant concentration that differs from that of the other two subregions.
Claim 12
Dependent Claim
69 words
A transistor, comprising: a channel; a gate; a dielectric structure that separates the gate from the channel; a first contact region; a second contact region, the channel separating the first contact region from the second contact region; and an anti-punchthrough region underlying the second contact region and having a first subregion and a second subregion, each subregion having a dopant concentration that differs from that of the other subregion.
Claim 13
Dependent Claim
69 words
A transistor, comprising: a channel; a gate; a dielectric structure that separates the gate from the channel; a first contact region; a second contact region, the channel separating the first contact region from the second contact region; and an anti-punchthrough region underlying the second contact region and having a first subregion and a second subregion, each subregion having a dopant concentration that differs from that of the other subregion.
Claim 14
Independent Claim
86 words
A method of forming a transistor on a substrate, comprising the following steps: forming a dielectric layer overlying the substrate; forming a gate structure overlying the dielectric layer, the gate structure having a first sidewall and a second sidewall, whereby a first contact region, a channel region and a second contact region are defined within the substrate; forming an anti-punchthrough region underlying the second contact region and having first and second subregions, each subregion having a dopant concentration that differs from that of the other subregion.
Claim 15
Independent Claim
86 words
A method of forming a transistor on a substrate, comprising the following steps: forming a dielectric layer overlying the substrate; forming a gate structure overlying the dielectric layer, the gate structure having a first sidewall and a second sidewall, whereby a first contact region, a channel region and a second contact region are defined within the substrate; forming an anti-punchthrough region underlying the second contact region and having first and second subregions, each subregion having a dopant concentration that differs from that of the other subregion.
Claim 16
Dependent Claim
178 words
A structure for forming a transistor on a semiconductor substrate comprising: a channel; a gate; a dielectric structure that separates the gate from the channel, said gate having first and second vertical sides perpendicular to the dielectric structure; a first vertical spacer positioned adjacent to the first vertical side of the gate; a second vertical spacer positioned adjacent to the first vertical spacer; a first contact region; a second contact region having a first subregion, a second subregion and a third subregion, each subregion having a dopant concentration that differs from that of the other two subregions, the channel separating the first contact region from the second contact region, wherein the first vertical spacer is generally aligned with a boundary of the second subregion, and the second vertical spacer is generally aligned with a boundary of the third subregion; and an anti-punchthrough region underlying the second contact region, the anti-punchthrough region having first and second subregions, each subregion of the anti-punchthrough region having a dopant concentration that differs from that of the other subregion of the anti-punchthrough region.
Claim 17
Dependent Claim
178 words
A structure for forming a transistor on a semiconductor substrate comprising: a channel; a gate; a dielectric structure that separates the gate from the channel, said gate having first and second vertical sides perpendicular to the dielectric structure; a first vertical spacer positioned adjacent to the first vertical side of the gate; a second vertical spacer positioned adjacent to the first vertical spacer; a first contact region; a second contact region having a first subregion, a second subregion and a third subregion, each subregion having a dopant concentration that differs from that of the other two subregions, the channel separating the first contact region from the second contact region, wherein the first vertical spacer is generally aligned with a boundary of the second subregion, and the second vertical spacer is generally aligned with a boundary of the third subregion; and an anti-punchthrough region underlying the second contact region, the anti-punchthrough region having first and second subregions, each subregion of the anti-punchthrough region having a dopant concentration that differs from that of the other subregion of the anti-punchthrough region.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2001-02-16 | 2001-08-18 | 2002-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-16 | 2005-08-18 | 2006-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-16 | 2009-08-18 | 2010-02-17 | $7700.00 | Window Closed / Lapsed |