Method of producing MOS devices
AssigneeShin-Etsu Handotai Co., Ltd.
InventorNobuyoshi Fujimaki
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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.degree. and 110.degree. 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.
Claims12
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.degree. and 1100.degree. for 4 hours or less.
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.degree. and 1100.degree. C. for 4 hours or less.
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.degree. to 1100.degree. 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.
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.degree. to 1100.degree. 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.
Dependencies are inferred from the claim text.