Method for manufacturing semiconductor device
AssigneeFujitsu Limited
InventorManabu Kojima
Life of this patent
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Abstract
A gate insulator film and a gate electrode are formed on a semiconductor substrate, and then a layered stack of a SiO2 film and a SiN film is formed on the entire surface. Subsequently, sidewalls made of polysilicon film are formed adjacent to the gate electrode via the layered stack of the SiO2 film and the SiN film. Then, using as a mask the gate electrode, portions of the layered stack adjacent to the gate electrode, and the sidewalls, an ion dopant is implanted into a device active region to thereby form source/drains therein, and the sidewalls are then removed. At this stage, since the gate insulator film is completely covered with the layered stack, the gate insulator film is not ablated or retreated even on a device isolation insulator film.
Claims28
A method for manufacturing a semiconductor device comprising the steps of:
- forming a gate insulator film and a gate electrode on a semiconductor substrate,
- forming a layered stack including two or more insulator films having etching rates different from one another on an entire surface of said semiconductor substrate,
- forming a mask sidewall adjacent to said gate electrode via said layered stack, said mask sidewall having an etching rate different from an etching rate of the outermost film among said insulator films in said layered stack,
- implanting a first ion dopant into said semiconductor substrate using said gate electrode, portions of said layered stack adjacent to said gate electrode, and said mask sidewall as a mask,
- removing said mask sidewall,
- performing anisotropic etching on an entire surface of said layered stack, thereby allowing part of said layered stack to remain only on a side of said gate electrode, and
- implanting a second ion dopant of the same conductivity type as that of said first ion dopant into said semiconductor substrate using said gate electrode and said layered stack as a mask, thereby forming a dopant diffusion layer.
A method for manufacturing a semiconductor device comprising the steps of:
- forming a gate insulator film and a gate electrode on a semiconductor substrate,
- forming a mask sidewall adjacent to said gate electrode,
- implanting a first ion dopant into said semiconductor substrate using said gate electrode and said mask sidewall as a mask,
- removing said mask sidewall,
- forming a layered stack adjacent to said gate electrode, the layered stack including two or more insulator films having etching rates different from one another, and
- implanting a second ion dopant of the same conductivity type as that of said first ion dopant into said semiconductor substrate using said gate electrode and said layered stack as a mask, thereby forming a dopant diffusion layer, wherein
- the step of forming said layered stack is carried out between the step of forming said gate insulator film and said gate electrode and the step of forming said mask sidewall, and
- in the step of removing said mask sidewall, only said mask sidewall is removed while protecting said gate insulator film using said layered stack.
Dependencies are inferred from the claim text.