Semiconductor device and method of manufacturing semiconductor device
The semiconductor device includes a first transistor including a first impurity layer containing boron or phosphorus, a first epitaxial layer formed above the first impurity layer, a first gate electrode formed above the first epitaxial layer with a first gate insulating film formed therebetween and first source/drain regions, and a second transistor including a second impurity layer containing boron and carbon, or arsenic or antimony, a second epitaxial layer formed above the second impurity layer, a second gate electrode formed above the second epitaxial layer with a second gate insulating film thinner than the first gate insulating film formed therebetween, and second source/drain regions.
1. A semiconductor device comprising:
a semiconductor substrate which includes a first region and a second region;
a first impurity layer formed in the semiconductor substrate of the first region and containing a first impurity of a first conductivity type;
a second impurity region layer formed in the semiconductor substrate of the second region and containing a second impurity, which has a diffusion constant smaller than a diffusion constant of the first impurity, of the first conductivity type;
a first semiconductor layer formed on the first impurity layer;
a second semiconductor layer formed on the second impurity layer;
a first gate insulating film formed on the first semiconductor layer;
a second gate insulating film thinner than the first gate insulating film formed on the second semiconductor layer;
a first gate electrode formed on the first gate insulating film;
a second gate electrode formed on the second gate insulating film;
a first source/drain region of a second conductivity type which is different from the first conductivity type formed in the first semiconductor layer; and
a second source/drain region of the second conductivity type formed in the second semiconductor layer.
2. The semiconductor device according to claim 1 , further comprising:
a first device isolation insulating film, which surrounds the first region, formed in the semiconductor substrate; and
a second device isolation insulating film formed in the semiconductor substrate.
3. The semiconductor device according to claim 1 , wherein
a concentration of the first impurity in the first semiconductor layer is lower than a concentration of the first impurity in the first impurity layer, and
a concentration of the second impurity in the second semiconductor layer is lower than a concentration of the second impurity in the second impurity layer.
4. The semiconductor device according to claim 1 , wherein
a concentration of the first impurity in the first semiconductor layer is lower than a concentration of the first impurity in the first impurity layer, and
a concentration of the first impurity in the second semiconductor layer is lower than a concentration of the first impurity in the second impurity layer.
5. The semiconductor device according to claim 1 , wherein
the first impurity is boron, and
the third impurity is carbon.
6. The semiconductor device according to claim 1 , wherein
the first impurity is phosphorus, and
the second impurity is arsenic or antimony.
7. The semiconductor device according to claim 1 , wherein
the second impurity layer contains germanium.
8. The semiconductor device according to claim 1 , further comprising:
a first well, which has the first conductivity type, formed in the first region and located under the first impurity layer; and
a second well, which has the first conductivity type, formed in the second region and located under the second impurity layer, wherein
a concentration of the first impurity layer is higher than the first semiconductor layer and the first well; and
a concentration of the second impurity layer is higher than the second semiconductor layer and the second well.
9. The semiconductor device according to claim 1 , wherein
a part of the first semiconductor layer is located under the first gate insulating film and between the first source/drain region, and
a part of the second semiconductor layer is located under the second gate insulating film and between the second source/drain region.
10. A semiconductor device comprising:
a semiconductor substrate which includes a first region and a second region;
a first impurity layer formed in the semiconductor substrate of the first region and containing a first impurity of a first conductivity type;
a second impurity layer formed in the semiconductor substrate of the second region and containing the first impurity and a third impurity which suppresses a diffusion of the first impurity;
a first semiconductor layer formed on the first impurity layer;
a second semiconductor layer formed on the second impurity layer;
a first gate insulating film formed on the first semiconductor layer;
a second gate insulating film thinner than the first gate insulating film formed on the second semiconductor layer;
a first gate electrode formed on the first gate insulating film;
a second gate electrode formed on the second gate insulating film;
a first source/drain region of a second conductivity type which is different from the first conductivity type formed in the first semiconductor layer; and
a second source/drain region of the second conductivity type formed in the second semiconductor layer.
11. The semiconductor device according to claim 10 , further comprising:
a first device isolation insulating film, which surrounds the first region, formed in the semiconductor substrate; and
a second device isolation insulating film, which surrounds the first region, formed in the semiconductor substrate.
12. The semiconductor device according to claim 10 , wherein
a concentration of the first impurity in the first semiconductor layer is lower than a concentration of the first impurity in the first impurity layer, and
a concentration of the second impurity in the second semiconductor layer is lower than a concentration of the second impurity in the second impurity layer.
13. The semiconductor device according to claim 10 , wherein
a concentration of the first impurity in the first semiconductor layer is lower than a concentration of the first impurity in the first impurity layer, and
a concentration of the first impurity in the second semiconductor layer is lower than a concentration of the first impurity in the second impurity layer.
14. The semiconductor device according to claim 10 , wherein
the first impurity is boron, and
the third impurity is carbon.
15. The semiconductor device according to claim 10 , wherein
the first impurity is phosphorus, and
the second impurity is arsenic or antimony.
16. The semiconductor device according to claim 10 , wherein
the second impurity layer contains germanium.
17. The semiconductor device according to claim 10 , further comprising:
a first well, which has the first conductivity type, formed in the first region and located under the first impurity layer; and
a second well, which has the first conductivity type, formed in the second region and located under the second impurity layer,
wherein a concentration of the first impurity layer is higher than the first semiconductor layer and the first well; and
a concentration of the second impurity layer is higher than the second semiconductor layer and the second well.
18. The semiconductor device according to claim 10 , wherein
a part of the first semiconductor layer is located under the first gate insulating film and between the first source/drain region, and
a part of the second semiconductor layer is located under the second gate insulating film and between the second source/drain region.