Semiconductor device and method for fabricating the same
A method for fabricating semiconductor device is disclosed. The method includes the steps of: providing a substrate having at least one fin-shaped structure thereon, in which the fin-shaped structure comprises a top portion and a bottom portion; and forming a doped layer and a first liner around the bottom portion of the fin-shaped structure.
1. A method for fabricating semiconductor device, comprising:
providing a substrate having at least one fin-shaped structure thereon and a hard mask on the fin-shaped structure, wherein the fin-shaped structure comprises a top portion and a bottom portion;
forming a second liner on the top portion and the bottom portion of the fin-shaped structure, wherein a top surface of the second liner contacts a bottom surface of the hard mask; and
forming a doped layer and a first liner around the bottom portion of the fin-shaped structure.
2. The method of claim 1 , further comprising:
forming the doped layer on the fin-shaped structure;
forming the first liner on the doped layer;
forming a dielectric layer on the first liner and around the bottom portion of the fin-shaped structure; and
removing the doped layer and the first liner around the top portion of the fin-shaped structure.
3. The method of claim 2 , further comprising:
forming the dielectric layer on the first liner;
removing part of the dielectric layer so that the top surface of the dielectric layer is between the top portion and the bottom portion of the fin-shaped structure; and
removing the doped layer and the first liner to expose the top portion of the fin-shaped structure.
4. The method of claim 2 , further comprising performing an annealing process on the first liner and the doped layer around the bottom portion of the fin-shaped structure after removing the doped layer and the first liner from the top portion of the fin-shaped structure.
5. The method of claim 1 , wherein the doped layer comprises borosilicate glass (BSG) or phosphosilicate glass (PSG).
6. The method of claim 1 , further comprising forming the hard mask on the fin-shaped structure before forming the doped layer.
7. The method of claim 1 , further comprising forming the second liner on the top portion and the bottom portion of the fin-shaped structure before forming the doped layer.
8. The method of claim 7 , wherein the first liner comprises silicon nitride and the second liner comprises silicon oxide.