EP0806794A2
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Method of forming shallow doped regions in a semiconductor substrate, using preamorphization and ion implantation
Assignee: Texas Instruments Inc
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Filing: 1997-04-28
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Granted: —
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Expires: 2017-04-28
Abstract
Abstract A method for tailoring the dopant profile of a doped region. A sub-amorphization implant of a non-electrically active material such as silicon or germanium is performed before a dopant implant. The energy of the amorphization implant is optimized to achieve the desired dopant profile. A lower energy, for example, produces a gradual junction, whereas, a higher energy can be used to produce a shallower junction region. In one application of the invention, a drain extension region of a MOSFET is formed using a sub-amorphization implant of silicon or germanium prior to a implant of boron. The energy of the sub-amorphization implant is chosen so that the projected range of the sub-amorphization implant is greater than three times the as-implanted junction depth of the boron implant in amorphous silicon. This places the interstitials away from the junction region to reduce TED. <IMAGE>
Inventors
- 👤 Akif Sultan
- 👤 Richard Scott List
- 👤 Vincent Maurice Mcneil
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 21:44
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; H10D62/00; H10D62/10; H10D62/13; H10D62/149; H10D62/151; H10D62/50; H10D62/53; H10P30/208; H10P30/21; H10P30/225; H10P30/28
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
48 words
A method for forming doped regions in a substrate, comprising the steps of: implanting a non-electrically active species into said substrate at a sub-amorphizing level to a first projected range; and implanting a dopant into said substrate and annealing said substrate to obtain a given junction depth, (xj).
Claim 2
Dependent Claim
39 words
The method of claim 1, wherein said step of implanting a non-electrically active species comprises implanting said non-electrically active species to a first projected range that is greater than said junction depth, (xj), to obtain shallow and abrupt junctions.
Claim 3
Dependent Claim
39 words
The method of claim 1, wherein said step of implanting a non-electrically active species comprises implanting said non-electrically active species to a first projected range that is less than said junction depth, (xj), to obtain deep and gradual junctions.
Claim 4
Independent Claim
31 words
The method of any preceding claim, wherein said step of implanting a non-electrically active species comprises implanting a non-electrically active species that is a group IV element on the Periodic Table.
Claim 5
Dependent Claim
22 words
The method of Claim 4, wherein said step of implanting a non-electrically active species comprises implanting a non-electrically active species comprising silicon.
Claim 6
Dependent Claim
22 words
The method of Claim 4, wherein said step of implanting a non-electrically active species comprises implanting a non-electrically active species comprising germanium.
Claim 7
Independent Claim
19 words
The method of any preceding claim, wherein said step of implanting said dopant comprises implanting a dopant comprising boron.
Claim 8
Independent Claim
24 words
The method of any of Claims 1 to 6, wherein said step implanting said dopant comprises implanting a dopant comprising BF 2 + .
Claim 9
Independent Claim
41 words
The method of any preceding claim, further comprising forming a doped region that is shallow and wherein said step of implanting a non-electrically active species is performed at an energy governed by the dopant dose, dopant energy and screen oxide thickness.
Claim 10
Independent Claim
14 words
A device formed according to the method of any of Claims 1 to 9.
Claim 11
Independent Claim
91 words
A method for forming a shallow drain extension region of a MOSFET transistor in a substrate comprising the steps of: implanting a species selected from Group IV of the periodic table into a region of said substrate at a sub-amorphizing level to a first projected range of the order of three times greater than a simulated, as- implanted junction depth; implanting a dopant into said region of said substrate at a desired dose and energy approximately corresponding to said simulated as-implanted junction depth; and annealing said substrate to diffuse said dopant.
Claim 12
Dependent Claim
29 words
The method of Claim 11, wherein said step of implanting said dopant comprises implanting a dopant that is diffused to a junction depth less than said first projected range.
Claim 13
Dependent Claim
17 words
The method of Claim 11, wherein said step of implanting said dopant comprises implanting dopant comprising boron.
Claim 14
Independent Claim
22 words
The method of any of Claims 11 to 13, wherein said step of implanting said species comprises implanting a species comprising silicon.
Claim 15
Independent Claim
22 words
The method of any of Claims 11 to 13, wherein said step of implanting said species comprises implanting a species comprising germanium.
Claim 16
Independent Claim
14 words
A device formed according to the method of any of Claims 11 to 15.
References Cited (Backward Citations)
No citation records indexed.
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