Method for fabricating semiconductor device
View Patent ↗A method for fabricating a semiconductor device is disclosed. The method includes: forming a photoresist film on a semiconductor substrate including a silicide forming region and non-silicide forming region; forming a photoresist pattern as a non-salicide pattern by patterning the photoresist film, so as to cover the non-silicide forming region and open the silicide forming region, with an overhang structure that a bottom is removed more compared to a top; forming a metal film on a top of the photoresist pattern and overall the semiconductor substrate in the silicide forming region; stripping the photoresist pattern and the metal film on the photoresist pattern; and forming a silicide metal film by annealing the metal film remaining on the semiconductor substrate. Therefore, the present invention simplifies a salicide process of a semiconductor device, making it possible to improve yields.
1. A method comprising:
providing a semiconductor substrate having a silicide forming region and a non-silicide forming region; and then
forming a photoresist film over the silicide forming region and the non-silicide forming region; and then
forming a photoresist pattern by patterning the photoresist film over the non-silicide forming region and exposing the silicide forming region, wherein a bottom portion of the photoresist pattern has an overhang structure; and then
forming a metal film over the photoresist pattern and the semiconductor substrate in the silicide forming region; and then
removing the photoresist pattern and the metal film formed over the photoresist pattern in the non-silicide forming region; and then
forming a silicide metal film by performing a first annealing process on the metal film formed over the semiconductor substrate,
wherein forming the photoresist pattern comprises:
exposing the non-silicide forming region over the photoresist film; and then
forming the photoresist pattern such that the critical dimension (CD) at the upper portion thereof is greater than the CD at the bottom portion thereof by developing the photoresist film.
2. The method of claim 1 , wherein forming the photoresist pattern further comprises:
exposing a portion of the photoresist film; and then
after exposing the portion of the photoresist film, performing a mono-chloro benzene (MCB) process on the surface of the exposed photoresist film.
3. The method of claim 1 , wherein the metal film includes at least one of cobalt, titanium, and titanium nitride.
4. The method of claim 1 , wherein the metal film comprises a multi-layered structure including a cobalt layer, a titanium layer, and a titanium nitride layer stacked in sequence.
5. The method of claim 1 , wherein the metal film has a gap formed at a bottom sidewall of the photoresist pattern.
6. The method of claim 1 , further comprising, before removing the metal film: forming a pre-silicide film by performing a second annealing process where the metal film is formed.
7. The method of claim 6 , wherein the second annealing process is performed at a temperature in a range between approximately 400 to 500° C.
8. The method of claim 1 , wherein the first annealing process is performed at a temperature in a range between approximately 800 to 850° C.
9. The method of claim 1 , wherein the thickness of the metal film is in a range between approximately 10 nm to 60 nm.
10. The method of claim 1 , further comprising, before forming the photoresist film:
sequentially forming a gate dielectric film and a gate electrode over the semiconductor substrate in the silicide forming region; and then
forming spacers at sidewalls of the gate dielectric film and the gate electrode; and then
forming source/drain regions in the semiconductor substrate at sides of the gate electrode,
wherein the metal film is formed over the uppermost surface of the gate electrode, the spacers, and the source/drain regions.
11. A method comprising:
providing a semiconductor substrate having a silicide forming region and a non-silicide forming region; and then
forming gate patterns in the silicide forming region and the non-silicide forming region; and then
forming spacers over sidewalls of the gate patterns; and then
forming a photoresist pattern over the non-silicide forming region, wherein a bottom sidewall portion of the photoresist pattern is slanted at an angle with respect to an upper sidewall portion of the photoresist pattern; and then
forming a metal film over the semiconductor substrate in the silicide forming region including the gate patterns and the spacers and also in the non-silicide forming region including the uppermost surface of the photoresist pattern and the upper sidewall portion of the photoresist pattern and not the bottom sidewall portion of the photoresist pattern; and then
forming a pre-silicide film on the metal film in the silicide forming region by performing a first annealing process; and then
removing the photoresist pattern including the metal film formed in the non-silicide forming region; and then
forming a silicide metal film by performing a second annealing process on the pre-silicide film formed over the gate patterns and the semiconductor substrate in the silicide forming region.
12. The method of claim 11 , wherein the pre-silicide film comprises CoSi.
13. The method of claim 11 , further comprising, after forming the silicide metal film:
removing the pre-silicide film formed over the spacers; and then
performing a cleaning process on the entire semiconductor substrate.
14. The method of claim 11 , wherein the first annealing process is performed at a temperature in a range between approximately 400 to 500° C.
15. The method of claim 11 , wherein the second annealing process is performed at a temperature in a range between approximately 800 to 850° C.
16. The method of claim 11 , wherein the metal film comprises at least one of cobalt, titanium, and titanium nitride.
17. The method of claim 11 , wherein the metal film comprises a multi-layered structure including a cobalt layer, a titanium layer, and a titanium nitride layer stacked in sequence.