Semiconductor device and method for fabricating the same
A method for fabricating semiconductor device includes the steps of: forming a gate structure on a substrate, forming a polymer block on a corner between the gate structure and the substrate, performing an oxidation process to form a first seal layer on sidewalls of the gate structure, and forming a source/drain region adjacent to two sides of the gate structure. Preferably, the polymer block includes fluorine, bromide, or silicon.
1. A method for fabricating semiconductor device, comprising:
forming a gate structure on a substrate;
forming a polymer block on a corner between the gate structure and the substrate, wherein the polymer block comprises fluorine, bromide, or silicon;
performing an oxidation process to form a first seal layer on sidewalls of the gate structure; and
forming a source/drain region adjacent to two sides of the gate structure.
2. The method of claim 1 , further comprising forming the polymer block on a corner between sidewalls of the gate structure a top surface of the substrate.
3. The method of claim 1 , further comprising performing the oxidation process to oxidize sidewalls of the gate structure to form the first seal layer.
4. The method of claim 1 , further comprising forming the first seal layer on sidewalls of the gate structure and an inner sidewall of the polymer block.
5. The method of claim 1 , further comprising:
forming a gate material layer on the substrate;
forming a first hard mask on the gate material layer;
forming a second hard mask on the first hard mask; and
patterning the second hard mask, the first hard mask, and the gate material layer to form the gate structure and forming the polymer block.
6. The method of claim 1 , further comprising:
forming a second seal layer on sidewalls of the first seal layer and the polymer block;
removing the second seal layer and the first seal layer to form a first spacer and a second spacer;
forming the source/drain region adjacent to two sides of the second spacer;
forming an interlayer-dielectric (ILD) layer on the gate structure; and
performing a replacement metal gate (RMG) process to transform the gate structure into a metal gate.
7. The method of claim 6 , wherein sidewalls of the polymer block contact the first spacer and the second spacer.
8. A semiconductor device, comprising:
a gate structure on a substrate;
a first spacer on sidewalls of gate structure;
a polymer block adjacent to the first spacer and on a corner between the gate structure and the substrate, wherein the polymer block comprises fluorine, bromide, or silicon; and
a source/drain region adjacent to two sides of the first spacer.
9. The semiconductor device of claim 8 , further comprising a second spacer on sidewalls of the first spacer, wherein the polymer block is between the first spacer and the second spacer.
10. The semiconductor device of claim 9 , wherein the second spacer and the polymer block comprise different materials.
11. The semiconductor device of claim 8 , wherein the first spacer and the polymer block comprise different materials.
12. The semiconductor device of claim 8 , further comprising an interfacial layer under the polymer block.
13. The semiconductor device of claim 12 , wherein the polymer block is surrounded by the first spacer, the interfacial layer, and the second spacer.
14. The semiconductor device of claim 8 , wherein the polymer block is surrounded by the first spacer, the substrate, and the second spacer.