Semiconductor device and manufacturing method of semiconductor device

1. A manufacturing method of a semiconductor device, comprising:

implanting a first impurity into a first region of a semiconductor substrate including the first region and a second region;

forming a semiconductor layer on the upper surface of the semiconductor substrate;

forming a trench in the semiconductor layer and the semiconductor substrate;

forming an isolation insulating film in the trench;

implanting a second impurity into the semiconductor layer in the second region;

forming a first gate insulating film on the semiconductor layer in the first region;

forming a second gate insulating film on the semiconductor layer in the second region;

forming a first gate electrode on the first gate insulating film;

forming a second gate electrode on the second gate insulating film;

forming a first source region and a first drain region in the semiconductor layer at both sides of the first gate electrode, the first source region and the first drain region having a conductivity type opposite to a conductivity type of the first impurity; and

forming a second source region and a second drain region in the semiconductor layer at both sides of the second gate electrode, the second source region and the second drain region having a conductivity type opposite to a conductivity type of the second impurity, wherein

the semiconductor substrate further includes a third region, and

the manufacturing method of the semiconductor device further comprises:

implanting a third impurity into the third region of the semiconductor substrate;

forming a third gate insulating film on the semiconductor layer in the third region;

forming a third gate electrode on the third gate insulating film; and

forming a third source region and a third drain region in the semiconductor layer at both sides of the third gate electrode, the third source region and the third drain region having a conductivity type opposite to a conductivity type of the third impurity,

wherein between the formation of the semiconductor layer and the formation of the third gate electrode, implanting an impurity into the semiconductor layer in the third region is not performed.

2. The manufacturing method of the semiconductor device according to claim 1 , wherein

the third impurity is boron or BF 2 , and

the manufacturing method of the semiconductor device further comprises:

implanting carbon into the third region of the semiconductor substrate.

3. A manufacturing method of a semiconductor device, comprising:

implanting a first impurity into a first region of a semiconductor substrate including the first region and a second region;

forming a semiconductor layer on the upper surface of the semiconductor substrate;

forming a trench in the semiconductor layer and the semiconductor substrate;

forming an isolation insulating film in the trench;

implanting a second impurity into the semiconductor layer in the second region;

forming a first gate insulating film on the semiconductor layer in the first region;

forming a second gate insulating film on the semiconductor layer in the second region;

forming a first gate electrode on the first gate insulating film;

forming a second gate electrode on the second gate insulating film;

forming a first source region and a first drain region in the semiconductor layer at both sides of the first gate electrode, the first source region and the first drain region having a conductivity type opposite to a conductivity type of the first impurity; and

forming a second source region and a second drain region in the semiconductor layer at both sides of the second gate electrode, the second source region and the second drain region having a conductivity type opposite to a conductivity type of the second impurity, wherein

the semiconductor substrate further includes a third region, and

the manufacturing method of the semiconductor device further comprises:

implanting a third impurity into the third region of the semiconductor substrate;

forming a third gate insulating film on the semiconductor layer in the third region;

forming a third gate electrode on the third gate insulating film;

forming a third source region and a third drain region in the semiconductor layer at both sides of the third gate electrode, the third source region and the third drain region having a conductivity type opposite to a conductivity type of the third impurity,

wherein implanting the first impurity is performed before forming the isolation insulating film and implanting the second impurity is performed after forming the isolation insulating film.