Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
202 words
A process for the fabrication of MOS transistor, comprising the steps of: forming a gate oxide film on a substrate; forming a p + polysilicon film doped with p type impurity ions over said gate oxide film; coating an insulating film and a photoresist film over said p + polysilicon film, in sequence; subjecting the resultant structure to a patterning to expose a portion of said insulating film; applying an etching method to said exposed insulating film with said photoresist film used as a mask; implanting fluorine ions in said p - polysilicon film with resultant insulating film used as a mask; removing the remaining photoresist film; carrying out an annealing method to form low density p - source/drain regions; applying an etching method to said p + polysilicon film to form a gate with said resultant insulating film used as a mask; removing said resultant insulating film; depositing an oxide film entirely over the resultant structure; applying an anisotropic etching to said oxide film to form spacers at side walls of said gate; implanting p type impurity ions in said substrate at a high density to form high density p + source/drain regions neighboring said low density p - source/drain regions.
Claim 2
Dependent Claim
202 words
A process for the fabrication of MOS transistor, comprising the steps of: forming a gate oxide film on a substrate; forming a p + polysilicon film doped with p type impurity ions over said gate oxide film; coating an insulating film and a photoresist film over said p + polysilicon film, in sequence; subjecting the resultant structure to a patterning to expose a portion of said insulating film; applying an etching method to said exposed insulating film with said photoresist film used as a mask; implanting fluorine ions in said p - polysilicon film with resultant insulating film used as a mask; removing the remaining photoresist film; carrying out an annealing method to form low density p - source/drain regions; applying an etching method to said p + polysilicon film to form a gate with said resultant insulating film used as a mask; removing said resultant insulating film; depositing an oxide film entirely over the resultant structure; applying an anisotropic etching to said oxide film to form spacers at side walls of said gate; implanting p type impurity ions in said substrate at a high density to form high density p + source/drain regions neighboring said low density p - source/drain regions.
Claim 3
Dependent Claim
28 words
A process according to claim 1, wherein said p + polysilicon film acts as a diffusion source for the formation of said low density p - source/drain regions.
Claim 4
Dependent Claim
39 words
A process according to claim 2, wherein said step of forming said p + polysilicon film comprises the steps of: depositing a polysilicon film on said gate oxide film; and doping said polysilicon film with p type impurity ions.
Claim 5
Dependent Claim
14 words
A process according to claim 3, wherein said doped impurity ions are boron ions.
Claim 6
Dependent Claim
66 words
A process according to claim 2, wherein said step of forming said p + polysilicon film comprises the steps of: coating said gate oxide film with n + polysilicon film; and doping said n + polysilicon film with BF 2 ions in such an amount that the BF 2 ions offset and surmount the n + type impurity ions doped in said n + polysilicon film.
Claim 7
Dependent Claim
21 words
A process according to claim 1, wherein said insulating film is selected from a nitride film or a CVD oxide film.
Claim 8
Dependent Claim
46 words
A process according to claim 1, wherein said p - source/drain regions gate is formed by the diffusion of said p type impurity ions doped in said p + polysilicon film into said substrate through said gate oxide film when said annealing method is carried out.
Claim 9
Dependent Claim
24 words
A process according to claim 7, wherein said low density p - source/drain regions have a junction depth of not more than 500 Å.
Claim 10
Dependent Claim
32 words
A process according to claim 1, wherein said fluorine ions are implanted at a dose of the twice amount of said p type impurity ions doped in said p + polysilicon film.