US5492845A
Expired / Lapsed
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Method of producing MOS devices
Assignee: Shin-Etsu Handotai Co Ltd
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Filing: 1994-01-13
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Granted: 1996-02-20
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Expires: 2014-01-13
Abstract
Abstract In a method of manufacturing a MOS device, of the type wherein an electrode film is deposited on a gate oxide film, after which a plurality of heat-treating steps are carried out in ambient gases and at a temperature range between 800° and 110° C., at least one of the heat-treating steps is carried out in a hydrogen atmosphere. The resultant MOS device has improved a time-dependent dielectric breakdown characteristics and maintained an improved time-zero dielectric breakdown characteristics which is comparable to that provided by the conventional hydrogen annealing.
Inventors
- 👤 Nobuyoshi Fujimaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:17
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01306; H10P; H10P32/00; H10P32/30; H10P32/302; Y; Y10; Y10S; Y10S148/00; Y10S148/003
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
65 words
A method of producing an MOS device comprising depositing a polysilicon film on a gate oxide film, and then diffusing a dopant into said polysilicon film, by a drive-in annealing process, for controlling the resistance of the polysilicon film, wherein said drive-in annealing process is carried out in a hydrogen atmosphere and at a temperature range between 800° and 1100° for 4 hours or less.
Claim 2
Independent Claim
65 words
A method of producing an MOS device comprising depositing a polysilicon film on a gate oxide film, and then diffusing a dopant into said polysilicon film, by a drive-in annealing process, for controlling the resistance of the polysilicon film, wherein said drive-in annealing process is carried out in a hydrogen atmosphere and at a temperature range between 800° and 1100° for 4 hours or less.
Claim 3
Dependent Claim
13 words
A method according to claim 1, wherein said dopant is phosphorus or boron.
Claim 4
Independent Claim
66 words
A method of producing an MIS device, comprising depositing a polysilicon film on a gate insulator film, and then diffusing a dopant into said polysilicon film by a drive-in annealing process for controlling the resistance of the polysilicon film, wherein said drive-in annealing process is carried out in a hydrogen atmosphere and at a temperature range between 800° and 1100° C. for 4 hours or less.
Claim 5
Independent Claim
66 words
A method of producing an MIS device, comprising depositing a polysilicon film on a gate insulator film, and then diffusing a dopant into said polysilicon film by a drive-in annealing process for controlling the resistance of the polysilicon film, wherein said drive-in annealing process is carried out in a hydrogen atmosphere and at a temperature range between 800° and 1100° C. for 4 hours or less.
Claim 6
Dependent Claim
13 words
A method according to claim 3, wherein said dopant is phosphorus or boron.
Claim 7
Dependent Claim
184 words
In the process of forming an MOS device which comprises: forming a wafer of single crystal material; hydrogen annealing said single crystal material wafer; oxidizing a surface of said annealed single crystal material wafer sufficient to form a gate oxide film thereon; depositing a polysilicon film on said gate electrode; depositing a layer comprising a dopant on said polysilicon film; carrying out a plurality of heat treating steps in ambient atmosphere at a temperature of about 800° to 1100° C., including at least one drive-in annealing step under an inert gas atmosphere, sufficient to diffuse said dopant into said polysilicon layer; and forming an electrode pattern by photolithography; the improvement which comprises: not subjecting said single crystal material to hydrogen annealing prior to oxidizing said wafer surface; not drive-in annealing said dopant under an inert gas atmosphere; and after depositing said dopant layer, and without increasing the number of said plurality of heat treating steps, carrying out at least one of said plurality of heat treating steps in a hydrogen atmosphere under hydrogen annealing conditions sufficient to drive said dopant into said polysilicon film.
Claim 8
Dependent Claim
184 words
In the process of forming an MOS device which comprises: forming a wafer of single crystal material; hydrogen annealing said single crystal material wafer; oxidizing a surface of said annealed single crystal material wafer sufficient to form a gate oxide film thereon; depositing a polysilicon film on said gate electrode; depositing a layer comprising a dopant on said polysilicon film; carrying out a plurality of heat treating steps in ambient atmosphere at a temperature of about 800° to 1100° C., including at least one drive-in annealing step under an inert gas atmosphere, sufficient to diffuse said dopant into said polysilicon layer; and forming an electrode pattern by photolithography; the improvement which comprises: not subjecting said single crystal material to hydrogen annealing prior to oxidizing said wafer surface; not drive-in annealing said dopant under an inert gas atmosphere; and after depositing said dopant layer, and without increasing the number of said plurality of heat treating steps, carrying out at least one of said plurality of heat treating steps in a hydrogen atmosphere under hydrogen annealing conditions sufficient to drive said dopant into said polysilicon film.
Claim 9
Dependent Claim
32 words
The improved process as claimed in claim 5 wherein said heat treating step carried out under a hydrogen atmosphere is carried out for a period of not more than about 4 hours.
Claim 10
Dependent Claim
23 words
The improved process as claimed in claim 5 wherein said dopant is a member selected from the group consisting of boron and phosphorus.
Claim 11
Dependent Claim
82 words
The improved process as claimed in claim 5 wherein, as a result of practicing said improved process, said MOS device has, as compared to an otherwise substantially the same MOS device made by carrying out said hydrogen annealing step prior to oxidation of said wafer: time zero dielectric breakdown (TZDB) characteristics of said gate electrode film which are at least maintained, time dependent dielectric breakdown (TDDB) characteristics of said gate electrode film which have reduced deterioration, and a reduction in slip characteristic.
Claim 12
Dependent Claim
184 words
In the process of forming an MIS device which comprises: forming a wafer of single crystal material; hydrogen annealing said single crystal material wafer; oxidizing a surface of said annealed single crystal material wafer sufficient to form a gate oxide film thereon; depositing a polysilicon film on said gate electrode; depositing a layer comprising a dopant on said polysilicon film; carrying out a plurality of heat treating steps in ambient atmosphere at a temperature of about 800° to 1100° C., including at least one drive-in annealing step under an inert gas atmosphere, sufficient to diffuse said dopant into said polysilicon layer; and forming an electrode pattern by photolithography; the improvement which comprises: not subjecting said single crystal material to hydrogen annealing prior to oxidizing said wafer surface; not drive-in annealing said dopant under an inert gas atmosphere; and after depositing said dopant layer, and without increasing the number of said plurality of heat treating steps, carrying out at least one of said plurality of heat treating steps in a hydrogen atmosphere under hydrogen annealing conditions sufficient to drive said dopant into said polysilicon film.
Claim 13
Dependent Claim
184 words
In the process of forming an MIS device which comprises: forming a wafer of single crystal material; hydrogen annealing said single crystal material wafer; oxidizing a surface of said annealed single crystal material wafer sufficient to form a gate oxide film thereon; depositing a polysilicon film on said gate electrode; depositing a layer comprising a dopant on said polysilicon film; carrying out a plurality of heat treating steps in ambient atmosphere at a temperature of about 800° to 1100° C., including at least one drive-in annealing step under an inert gas atmosphere, sufficient to diffuse said dopant into said polysilicon layer; and forming an electrode pattern by photolithography; the improvement which comprises: not subjecting said single crystal material to hydrogen annealing prior to oxidizing said wafer surface; not drive-in annealing said dopant under an inert gas atmosphere; and after depositing said dopant layer, and without increasing the number of said plurality of heat treating steps, carrying out at least one of said plurality of heat treating steps in a hydrogen atmosphere under hydrogen annealing conditions sufficient to drive said dopant into said polysilicon film.
Claim 14
Dependent Claim
32 words
The improved process as claimed in claim 9 wherein said heat treating step carried out under a hydrogen atmosphere is carried out for a period of not more than about 4 hours.
Claim 15
Dependent Claim
23 words
The improved process as claimed in claim 9 wherein said dopant is a member selected from the group consisting of boron and phosphorus.
Claim 16
Dependent Claim
82 words
The improved process as claimed in claim 9 wherein, as a result of practicing said improved process, said MOS device has, as compared to an otherwise substantially the same MOS device made by carrying out said hydrogen annealing step prior to oxidation of said wafer: time zero dielectric breakdown (TZDB) characteristics of said gate electrode film which are at least maintained, time dependent dielectric breakdown (TDDB) characteristics of said gate electrode film which have reduced deterioration, and a reduction in slip characteristic.
References Cited (Backward Citations)
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