Method for fabricating semiconductor device
A method for fabricating a semiconductor device comprises forming a dummy gate pattern and a spacer that is arranged on a sidewall of the dummy gate pattern on a substrate, forming an air gap on both sides of the dummy gate pattern by removing the spacer, exposing the substrate by removing the dummy gate pattern, and sequentially forming a gate insulating film including a high-k insulating film and a metal gate electrode on the exposed substrate.
1. A method for fabricating a semiconductor device comprising:
forming a dummy gate pattern on a substrate;
forming a spacer on a sidewall of the dummy gate pattern and on the substrate;
forming a trench by etching the substrate at a side surface of the spacer;
forming a semiconductor pattern in the trench where the semiconductor pattern protrudes from the trench above a top surface of the substrate;
forming a first recess by removing at least part of the spacer;
forming an air gap on both sides of the dummy gate pattern by forming a blocking film that covers the first recess and the dummy gate pattern;
exposing the substrate by removing the dummy gate pattern; and
sequentially forming a gate insulating film including a high-k insulating film and a metal gate electrode on the exposed substrate.
2. The method for fabricating the semiconductor device of claim 1 , wherein forming the first recess comprises:
forming an interlayer insulating film that at least partially covers a sidewall of the spacer and exposes a top surface of the spacer; and
forming the first recess in the interlayer insulating film by removing at least part of the spacer.
3. The method for fabricating the semiconductor device of claim 2 , further comprising conformally forming a liner within the first recess.
4. The method for fabricating the semiconductor device of claim 2 , wherein removing at least part of the spacer comprises leaving a lower part of the spacer on the substrate.
5. The method for fabricating the semiconductor device of claim 1 , wherein a part of the blocking film fills up an upper portion of the first recess while leaving the air gap in a lower portion of the first recess.
6. The method for fabricating the semiconductor device of claim 5 , wherein removing the dummy gate pattern comprises:
exposing the dummy gate pattern by smoothing the blocking film; and
forming a trench that exposes the substrate in the interlayer insulating film by etching the exposed dummy gate pattern.
7. The method for fabricating the semiconductor device of claim 1 , further comprising forming an air gap spacer on the sidewall of the dummy gate pattern.
8. The method for fabricating the semiconductor device of claim 7 , wherein forming the air gap spacer comprises:
forming a filler that fills up the first recess; and
forming a second recess by removing a part of the filler.
9. The method for fabricating the semiconductor device of claim 8 , further comprising removing the filler after forming the air gap spacer.
10. A method of fabricating a semiconductor device, the method comprising:
forming a first gate electrode and a second gate electrode on a substrate;
forming an interlayer pattern between the first and second gate electrodes;
conformally forming a first layer on the first and second gate electrodes and on the interlayer pattern; and then
forming a blocking film on the first and second gate electrodes and on the interlayer pattern,
wherein the blocking film only partially fills a first air gap between the first gate electrode and the interlayer pattern, and only partially fills a second air gap between the second gate electrode and the interlayer pattern.
11. The method of fabricating the semiconductor device of claim 10 , the method further comprising the following steps prior to formation of the first layer:
forming a first spacer on a first sidewall of the first gate electrode and forming a second spacer on a second sidewall of the second gate electrode; and
removing the first and second spacer to form the first and second air gaps.
12. The method of fabricating the semiconductor device of claim 11 , wherein the first and second gate electrodes comprise first and second dummy gate electrodes, the interlayer pattern comprises a patterned interlayer insulating film, and the first layer comprises a liner layer the method further comprising:
removing the first and second dummy gate electrodes; and
forming first and second metal gate electrodes in place of the first and second dummy gate electrodes.
13. The method of fabricating the semiconductor device of claim 11 , the method further comprising:
forming a trench by etching the substrate between the first and second spacers, and
forming a semiconductor pattern in the trench, the semiconductor pattern protruding above a top surface of the substrate.
14. The method of fabricating the semiconductor device of claim 10 , wherein the first and second gate electrodes comprise first and second dummy gate electrodes, the interlayer pattern comprises a patterned interlayer insulating film, and the first layer comprises a liner the method further comprising the following steps after forming the liner but prior to forming the blocking film:
forming a filler on the liner that fills up the first and second air gaps;
forming a first recess and a second recess by removing respective first and second portions of filler;
forming a first air gap spacer on a sidewall of the first recess and forming a second air gap spacer on a sidewall of the second recess; and
removing the filler after forming the first and second air gap spacers.