Method of fabricating a semiconductor device

Claim 1

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas in which said fluorine family etching gas is taken from a group consisting of one of CH 2 F 2 , CHF 3 +O 2 , CHF 3 +CF 4 , CHF 3 +C 2 F 6 , CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gas where the last two mentioned gases contain O 2 at a level which is less than 30 volume %.

Claim 2

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas in which said fluorine family etching gas is taken from a group consisting of one of CH 2 F 2 , CHF 3 +O 2 , CHF 3 +CF 4 , CHF 3 +C 2 F 6 , CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gas where the last two mentioned gases contain O 2 at a level which is less than 30 volume %.

Claim 6

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas which contains C and H, and further in which etching of said single-crystal silicon or polysilicon, and forming of said deposition film are performed in separate chambers.

Claim 7

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas which contains C and H, and further in which etching of said single-crystal silicon or polysilicon, and forming of said deposition film are performed in separate chambers.

Claim 8

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas which contains C and H, and further in which said deposition film is an approximately 10 nm thick C--H deposition film.

Claim 9

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas which contains C and H, and further in which said deposition film is an approximately 10 nm thick C--H deposition film.

Claim 10

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas which contains C and H, and further in which said rounded corners are on exposed edges of a trench having an opening portion with radiused corners.

Claim 11

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas which contains C and H, and further in which said rounded corners are on exposed edges of a trench having an opening portion with radiused corners.

Claim 12

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas which contains C and H, and further in which said rounded corners are on edges of wiring having upper radiused corners.

Claim 13

A method of fabricating a semiconductor device in which a single-crystal silicon or polysilicon is etched by using an etching gas which contains SF 6 or NF 3 as a main etching gas, said method comprising the step of forming a deposition film on a surface to be main-etched before main-etching said single-crystal silicon or polysilicon, to obtain rounded corners, said deposition film being formed by pre-etching said surface by using a fluorine family etching gas which contains C and H, and further in which said rounded corners are on edges of wiring having upper radiused corners.

Claim 14

A method of fabricating a semiconductor device comprising the steps of: forming a mask on top of a single-crystal silicon substrate; pre-etching said top of said single-crystal silicon substrate by using a fluorine family etching gas selected from a group consisting of CHF 3 +CF 4 , CHF 3 +C 2 F 6 CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gases, which contain 0-30% volume % of CHF 3 , everywhere where there is no mask, and etching the resulting surface by using a fluorine family etching gas selected from a group consisting of CHF 3 +O 2 gas which contains 70-100 volume % of CHF 3 , and CHF 3 +CF 4 , CHF 3 +C 2 F 6 , CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gases which contain 50-80 volume % of CHF 3 , in order to form a C--H deposition film on top of said silicon substrate; and then etching the resulting deposition film and said substrate by using an etching gas, of which a main gas is SF 6 or NF 3 , to form a trench having an opening portion with tapered and radiused corners.

Claim 15

A method of fabricating a semiconductor device comprising the steps of: forming a mask on top of a single-crystal silicon substrate; pre-etching said top of said single-crystal silicon substrate by using a fluorine family etching gas selected from a group consisting of CHF 3 +CF 4 , CHF 3 +C 2 F 6 CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gases, which contain 0-30% volume % of CHF 3 , everywhere where there is no mask, and etching the resulting surface by using a fluorine family etching gas selected from a group consisting of CHF 3 +O 2 gas which contains 70-100 volume % of CHF 3 , and CHF 3 +CF 4 , CHF 3 +C 2 F 6 , CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gases which contain 50-80 volume % of CHF 3 , in order to form a C--H deposition film on top of said silicon substrate; and then etching the resulting deposition film and said substrate by using an etching gas, of which a main gas is SF 6 or NF 3 , to form a trench having an opening portion with tapered and radiused corners.

Claim 17

A method of fabricating a semiconductor device comprising the steps of: forming a mask on top of a polysilicon film on a single-crystal silicon substrate; pre-etching a top of said polysilicon film by using a fluorine family etching gas selected from a group consisting of CHF 3 +CF 4 , CHF 3 +C 2 F 6 , CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gases, which contain 0-30 volume % of CHF 3 , everywhere where there is no mask, and etching the resulting surface by using a fluorine family etching gas selected from a group consisting of CHF 3 +O 2 gas which contains 70-100 volume % of CHF 3 , and CHF 3 +CF 4 , CHF 3 +C 2 F 6 , CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gases which contain 50-80 volume % of CHF 3 in order to form a C--H deposition film on the surface of said polysilicon film; and then etching the resulting deposition film and said polysilicon film by using an etching gas, of which a main gas is SF 6 or NF 3 , to form wiring having upper tapered radiused corners.

Claim 18

A method of fabricating a semiconductor device comprising the steps of: forming a mask on top of a polysilicon film on a single-crystal silicon substrate; pre-etching a top of said polysilicon film by using a fluorine family etching gas selected from a group consisting of CHF 3 +CF 4 , CHF 3 +C 2 F 6 , CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gases, which contain 0-30 volume % of CHF 3 , everywhere where there is no mask, and etching the resulting surface by using a fluorine family etching gas selected from a group consisting of CHF 3 +O 2 gas which contains 70-100 volume % of CHF 3 , and CHF 3 +CF 4 , CHF 3 +C 2 F 6 , CHF 3 +CF 4 +O 2 , and CHF 3 +C 2 F 6 +O 2 gases which contain 50-80 volume % of CHF 3 in order to form a C--H deposition film on the surface of said polysilicon film; and then etching the resulting deposition film and said polysilicon film by using an etching gas, of which a main gas is SF 6 or NF 3 , to form wiring having upper tapered radiused corners.