US4004950A
Expired / Lapsed
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Method for improving the doping of a semiconductor material
Assignee: Bpifrance Financement SA
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Filing: 1975-01-10
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Granted: 1977-01-25
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Expires: 1995-01-10
Abstract
Abstract In a first step, the semiconductor material is doped in a known manner with impurities having a given conductivity type and a given concentration profile. In a second step, the material is maintained at a high temperature, bombarded with a beam of particles which are accelerated with a given energy so as to penetrate into the crystal during a predetermined time interval. The resultant migration of impurities produces an increase in the impurity concentration irrespective of the sign of the initial concentration gradient within a zone adjacent to the zone of stopping of the particles.
Inventors
- 👤 Pierre Baruch
- 👤 Joseph Borel
- 👤 Joel Monnier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:31
CPC Classifications
H; H10; H10P; H10P34/00; H10P34/40; H10D; H10D99/00; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10P30/208; H10P30/225; H10P32/00; H10W; H10W15/00; H10W15/01
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
134 words
A method for improving the doping of a semiconductor material with impurities of a given conductivity type, wherein said method consists in a first step in doping said material with said impurities which have a given concentration profile and, in a second step, in maintaining said material at a high temperature, in bombarding said material with a beam of a constant intensity of particles accelerated with a constant energy which is sufficient to penetrate into the material during a given time interval so as to obtain migration of the impurities resulting in an increase in the impurity concentration irrespective of the sign of the initial concentration gradient within a zone adjacent to the zone of stopping of the particles, said zone being in a portion of said material which is doped with said impurity.
Claim 2
Independent Claim
134 words
A method for improving the doping of a semiconductor material with impurities of a given conductivity type, wherein said method consists in a first step in doping said material with said impurities which have a given concentration profile and, in a second step, in maintaining said material at a high temperature, in bombarding said material with a beam of a constant intensity of particles accelerated with a constant energy which is sufficient to penetrate into the material during a given time interval so as to obtain migration of the impurities resulting in an increase in the impurity concentration irrespective of the sign of the initial concentration gradient within a zone adjacent to the zone of stopping of the particles, said zone being in a portion of said material which is doped with said impurity.
Claim 3
Dependent Claim
44 words
A method according to claim 1, wherein the energy of the beam of non-doping ions is such that the zone of stopping of said particles is adjacent to the region in which it is desired to obtain a rise in the impurity concentration gradient.
Claim 4
Dependent Claim
32 words
A method according to claim 1, wherein said particles are non-doping and the fluence of the beam is such that the desired value of the rise in the concentration gradient is obtained.
Claim 5
Dependent Claim
19 words
A method according to claim 1, wherein the acceleration energy is within the range of 200 to 700 keV.
Claim 6
Dependent Claim
18 words
A method according to claim 1, wherein the temperature is within the range of 700° to 1000° C.
Claim 7
Dependent Claim
22 words
A method according to claim 1, wherein the particles are selected from the group comprising the molecules, the atoms and the ions.
Claim 8
Dependent Claim
28 words
A method according to claim 6, wherein the particles are non-doping and are selected from the group comprising the protons and the molecular ions H 2 + .
Claim 9
Dependent Claim
18 words
A method according to claim 1, wherein the particles are doping in the case of the semiconductor material.
Claim 10
Dependent Claim
18 words
A method according to claim 1, wherein the particles are non-doping in the case of said semiconductor material.
Claim 11
Dependent Claim
35 words
A method according to claim 7, wherein the non-doping particles are protons and wherein the fluence of the proton beam is within the range of 10 15 p/cm 2 and 10 19 p/cm 2 .
Claim 12
Dependent Claim
23 words
A method according to claim 1, wherein the doping impurities are selected from the elements which have an energy level of small depth.
Claim 13
Dependent Claim
25 words
A method according to claim 11, wherein the impurities are selected from the elements of columns III and V of the periodic table of elements.
Claim 14
Dependent Claim
18 words
A method according to claim 1, wherein the doping of the first step of said method is homogeneous.
Claim 15
Dependent Claim
20 words
A method according to claim 1, wherein the doping of the first step of said method has any concentration profile.
Claim 16
Dependent Claim
51 words
Application of the method according to claim 1 to the fabrication of a bipolar transistor, wherein said method consists in forming within the collector zone between the base and the collector contact a region having an impurity concentration which is higher than the concentration of the remainder of the collector zone.
Claim 17
Dependent Claim
58 words
Application of the method according to claim 1 to the fabrication of a diode on an insulating substrate, wherein said method consists in forming within the n-type region of said diode at the interface of said region with said substrate a thin zone having an impurity concentration which is higher than that of the remainder of said region.
Claim 18
Dependent Claim
47 words
Application of the method according to claim 1 to the fabrication of a depletion MOS transistor, wherein said method consists in forming in the zone of the conducting channel which separates the drain contact from the source contact a region which exhibits a very steep doping profile.
Claim 19
Dependent Claim
26 words
Application of the method according to claim 1 to the fabrication of a buried-electrode field-effect transistor, wherein said electrode is formed by means of said method.
Claim 20
Dependent Claim
36 words
A method according to claim 1, wherein said material is subjected to a plurality of said bombardment steps, each bombardment being with particles accelerated at a different energy, the energy being maintained constant throughout each bombardment.
Claim 21
Independent Claim
90 words
A method of increasing the concentration of an impurity having a given conductivity type within a portion of a semiconductor material doped with said impurity comprising: heating said material to an elevated temperature, bombarding said heated material with a stream of particles, maintaining the intensity of said beam constant throughout said bombardment, maintaining the energy at which said particles are accelerated constant throughout said bombardment, said energy being at a sufficient level so that the zone in which said particles are stopped in said material is doped with said impurity.
Claim 22
Independent Claim
90 words
A method of increasing the concentration of an impurity having a given conductivity type within a portion of a semiconductor material doped with said impurity comprising: heating said material to an elevated temperature, bombarding said heated material with a stream of particles, maintaining the intensity of said beam constant throughout said bombardment, maintaining the energy at which said particles are accelerated constant throughout said bombardment, said energy being at a sufficient level so that the zone in which said particles are stopped in said material is doped with said impurity.
Claim 23
Dependent Claim
43 words
A method according to claim 20 wherein said elevated temperature is between 700° to 1000° C, said particles are protons, said intensity is from 10 15 p/cm 2 to 10 19 p/cm 2 , and said energy is from 200 to 700 keV.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |