US5918140A
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Deposition of dopant impurities and pulsed energy drive-in
Assignee: University of California
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Filing: 1997-06-16
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Granted: 1999-06-29
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Expires: 2017-06-16
Abstract
Abstract A semiconductor doping process which enhances the dopant incorporation achievable using the Gas Immersion Laser Doping (GILD) technique. The enhanced doping is achieved by first depositing a thin layer of dopant atoms on a semiconductor surface followed by exposure to one or more pulses from either a laser or an ion-beam which melt a portion of the semiconductor to a desired depth, thus causing the dopant atoms to be incorporated into the molten region. After the molten region recrystallizes the dopant atoms are electrically active. The dopant atoms are deposited by plasma enhanced chemical vapor deposition (PECVD) or other known deposition techniques.
Inventors
- 👤 Paul Wickboldt
- 👤 Paul G. Carey
- 👤 Patrick M. Smith
- 👤 Albert R. Ellingboe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:36
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/17; H10P32/171; H10P32/14; H10P32/1408
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
92 words
A doping process consisting of: depositing dopant on a surface of a material to be doped using a dopant atmosphere selected from the group consisting of BF 2 , PF 5 , AsH 3 , B 2 H 6 , PH 3 , AsF 5 , and organometallics; and incorporating the dopant into the material by pulsed energy processing using pulsed energy selected from the group consisting of pulsed laser energy and pulsed ion-beam energy to produce a dose of about 10 15 cm -2 electrically active dopant atoms per energy pulse.
Claim 2
Dependent Claim
92 words
A doping process consisting of: depositing dopant on a surface of a material to be doped using a dopant atmosphere selected from the group consisting of BF 2 , PF 5 , AsH 3 , B 2 H 6 , PH 3 , AsF 5 , and organometallics; and incorporating the dopant into the material by pulsed energy processing using pulsed energy selected from the group consisting of pulsed laser energy and pulsed ion-beam energy to produce a dose of about 10 15 cm -2 electrically active dopant atoms per energy pulse.
Claim 3
Dependent Claim
41 words
The process of claim 1, wherein depositing the dopant is carried out by a technique selected from the group consisting of plasma enhanced chemical vapor deposition, sputtering, condensation through cooling the material to be doped, thermal decomposition CVD, and photolytic decomposition.
Claim 4
Dependent Claim
32 words
The process of claim 1, wherein the pulsed laser energy is provided by a laser selected from the group consisting of excimer lasers, copper vapor lasers, dye lasers, and pulsed NdYAG lasers.
Claim 5
Dependent Claim
17 words
The process of claim 3, wherein the pulsed laser energy is produced by an XeCl excimer laser.
Claim 6
Dependent Claim
54 words
The process of claim 4, wherein the pulsed excimer laser is constructed to operate at a wavelength of 308 nm, and controlling the excimer laser to produce 1 to about 10 pulses with an energy pulse of 50 to 1000 mj cm -2 , and with a pulse length of 5 to 100 ns.
Claim 7
Dependent Claim
141 words
An improved semiconductor doping process comprising: depositing a layer of dopant atoms/molecules on a surface of a semiconductor in an atmosphere selected from the group consisting of BF 3 , PF 5 , AsH 3 , B 2 H 6 , PH 3 , AsF 5 , PH 3 , and organometallics, followed by exposure to one or more energy pulses using a pulsed ion-beam machine or a pulsed laser supplied with a wavelength such that the energy is absorbed in the near surface region of the semiconductor which melts a portion of the semiconductor, forming a molten region thereby causing the dopant atoms/molecules to be incorporated into the molten region at a dose rate of about 10 15 cm -2 per energy pulse; and allowing the molten region to recrystallize whereby the dopant atoms/molecules are electrically active in the semiconductor.
Claim 8
Dependent Claim
141 words
An improved semiconductor doping process comprising: depositing a layer of dopant atoms/molecules on a surface of a semiconductor in an atmosphere selected from the group consisting of BF 3 , PF 5 , AsH 3 , B 2 H 6 , PH 3 , AsF 5 , PH 3 , and organometallics, followed by exposure to one or more energy pulses using a pulsed ion-beam machine or a pulsed laser supplied with a wavelength such that the energy is absorbed in the near surface region of the semiconductor which melts a portion of the semiconductor, forming a molten region thereby causing the dopant atoms/molecules to be incorporated into the molten region at a dose rate of about 10 15 cm -2 per energy pulse; and allowing the molten region to recrystallize whereby the dopant atoms/molecules are electrically active in the semiconductor.
Claim 9
Dependent Claim
36 words
The process of claim 6, wherein depositing the layer of dopant atoms/molecules is carried out by a technique selected from the group consisting of PECVD, glow discharge CVD, sputtering, condensation, photolytic decomposition, and thermal decomposition CVD.
Claim 10
Dependent Claim
35 words
The process of claim 6, additionally including forming the one or more energy pulses using a pulsed laser selected from the group consisting of excimer lasers, copper vapor lasers, dye lasers, and pulsed NdYAG lasers.
Claim 11
Dependent Claim
21 words
The process of claim 6, wherein the one or more energy pulses have a pulse duration of less than 1 ms.
Claim 12
Dependent Claim
19 words
The process of claim 6, wherein the one or more energy pulses are produced by an XeCl excimer laser.
Claim 13
Dependent Claim
17 words
The process of claims 6, additionally including forming the semiconductor from at least a layer of silicon.
Claim 14
Dependent Claim
13 words
The process of claim 11, wherein the molten region recrystallizes as doped polysilicon.
Claim 15
Dependent Claim
84 words
In a process for doping a semiconductor material using pulsed laser energy or pulsed ion-beam energy processing, the improvement comprising: forming a layer of dopant atoms on a surface of the semiconductor material from the group consisting of BF 3 , PF 5 , AsH 3 , B 2 H 6 , PH 3 , AsF 5 , and organometallics prior to pulsed energy processing to produce a dopant dose rate of about 10 15 cm -2 electrically active dopant atoms per energy pulse.
Claim 16
Dependent Claim
84 words
In a process for doping a semiconductor material using pulsed laser energy or pulsed ion-beam energy processing, the improvement comprising: forming a layer of dopant atoms on a surface of the semiconductor material from the group consisting of BF 3 , PF 5 , AsH 3 , B 2 H 6 , PH 3 , AsF 5 , and organometallics prior to pulsed energy processing to produce a dopant dose rate of about 10 15 cm -2 electrically active dopant atoms per energy pulse.
Claim 17
Dependent Claim
79 words
The improvement of claim 13, additionally including forming the dopant atoms from a material which is electrically active following the pulsed energy processing, and wherein forming of the layer of dopant atoms is carried out such that a dose of electrically active dopant atoms formed from a layer of dopant atoms per energy pulse is about 10 2 cm -2 greater than a dose of dopant atoms formed by pulsed energy processing in the presence of a dopant atmosphere.
Claim 18
Dependent Claim
27 words
The improvement of claim 13, wherein the pulsed energy processing is carried out using one or more pulses from an excimer laser or an ion beam machine.
References Cited (Backward Citations)
US4147563A
Cited
US5316969A
Cited
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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) | 2002-06-28 | 2002-12-28 | 2003-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-06-28 | 2006-12-28 | 2007-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-06-28 | 2010-12-28 | 2011-06-29 | $7700.00 | Window Closed / Lapsed |