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EP0116702A2
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Method for forming polycrystalline silicon resistors having reproducible and controllable resistivities
Assignee: International Business Machines Corp
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Filing: 1983-12-01
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Granted: —
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Expires: 2003-12-01
Abstract
Abstract The ion implantation of high doses of electrically- inactive species such as carbon or nitrogen, into heavily doped polycrystalline silicon produces high resistivity material (10 3- 10 5 ohms per square) having superior characteristics with respect to reproducibility and controllability as compared to lightly doped polycrystalline silicon. This material is suitable for forming resistors ideally suited for various applications in the integrated circuit field such as load devices in of high speed logic circuits where it is mandatory to control the sheet resistance precisely.
Inventors
- 👤 Robert Forbell Bartholomew
- 👤 David Richard Campbell, Sr.
- 👤 Howard Helge Hansen
- 👤 Charles William Koburger Iii
- 👤 John M. Wursthorn
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 10:33
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/40; H10D1/47; H10P; H10P32/00; H10P32/30; H10P32/302
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
100 words
A method of forming high resistivity polycrystalline silicon film disposed on a substrate comprising the steps of : a) heavily doping the polycrystalline silicon film with an impurity either of P or N type, in an amount well in excess of the trapping density of said film to saturate them, b) ion implanting the polycrystalline silicon film with an electrically inactive specie taken from the group consisting of carbon and nitrogen, in order to enhance the sheet resistivity, and c) annealing the polycrystalline silicon film in order to activate electrically the dopants and to heal the defects in the grains.
Claim 2
Independent Claim
100 words
A method of forming high resistivity polycrystalline silicon film disposed on a substrate comprising the steps of : a) heavily doping the polycrystalline silicon film with an impurity either of P or N type, in an amount well in excess of the trapping density of said film to saturate them, b) ion implanting the polycrystalline silicon film with an electrically inactive specie taken from the group consisting of carbon and nitrogen, in order to enhance the sheet resistivity, and c) annealing the polycrystalline silicon film in order to activate electrically the dopants and to heal the defects in the grains.
Claim 3
Dependent Claim
29 words
A method as recited in claim 1 wherein said electrically inactive species is implanted with a concentration in the 3.10 19 to 3 . 10 21 at/cm 3 range.
Claim 4
Dependent Claim
32 words
A method as recited in claim 1 or 2 wherein said impurity is boron which is implanted with a dose of about 6.4 10 14 at/cm 2 , at about 50 keV.
Claim 5
Dependent Claim
19 words
A method as recited in claim 3 wherein said inactive species is nitrogen which is implanted at 180 keV.
Claim 6
Dependent Claim
19 words
A method as recited in claim 3 wherein said inactive species is carbon which is implanted at 75 kev.
Claim 7
Dependent Claim
26 words
A method as recited in claim 3 wherein said inactive species is carbon which is implanted at 40 keV at 90 keV in two successive steps.
Claim 8
Dependent Claim
35 words
A method as recited in claim 1 or 2 wherein said impurity is phosphorous which is implanted with a dose in the 5.10 14 - 1.8 10 15 at/cm 2 range, at about 130 keV.
Claim 9
Dependent Claim
19 words
A method as recited in claim 7 wherein said inactive specie is carbon which is implanted at 75 keV.
Claim 10
Independent Claim
25 words
A method as recited in any of above claims wherein said film is annealed in a 2 minute 0 2 /28 minute N 2 cycle.
Claim 11
Independent Claim
35 words
A method as recited in any of above claims wherein said substrate comprises a silicon wafer having a layer of silicon dioxide disposed thereon, said polycrystalline silicon film being deposited on the silicon dioxide layer.
Claim 12
Dependent Claim
13 words
A structure produced in accordance with the method of any of above claims.
Claim 13
Dependent Claim
22 words
A structure as recited in claim 11 wherein a protective coating such as thermal oxide is provided over the polycrystalline silicon film.
References Cited (Backward Citations)
No citation records indexed.
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