Method for fabricating semiconductor device by using PECYCLE-CVD process
Disclosed is a method for fabricating a semiconductor device by using a PECYCLE-CVD process. The method includes the steps of feeding source gas into a process chamber for predetermined time within one cycle, allowing reaction gas to flow in the process chamber at least until a plasma reaction is finished in the process chamber and feeding purge gas into the process chamber for a predetermined time within one cycle, thereby purging residual products remaining in the process chamber after source gas is reacted, forming plasma in the process chamber for a predetermined time within one cycle so as to allow reaction gas to react with plasma, thereby depositing a thin film on a wafer, and feeding purge gas into the process chamber for a predetermined time within one cycle, thereby purging residual products remaining in the process chamber after reaction gas is reacted. Superior step-coverage and uniformity of the thin film are achieved while depositing the thin film at a higher speed.
1. A method for fabricating a semiconductor device by using a PECYCLE-CVD process, the method comprising the steps of:
i) feeding source gas into a process chamber for predetermined time within one cycle;
ii) allowing reaction gas to flow in the process chamber at least until a plasma reaction is finished in the process chamber and feeding purge gas into the process chamber for a predetermined time within one cycle, thereby purging residual products remaining in the process chamber after source gas is reacted;
iii) forming plasma in the process chamber for a predetermined time within one cycle so as to allow reaction gas to react with plasma, thereby depositing a thin film on a wafer; and
iv) feeding purge gas into the process chamber for a predetermined time within one cycle, thereby purging residual products remaining in the process chamber after reaction gas is reacted.
2. The method as claimed in claim 1 , wherein reaction gas is continuously fed into the process chamber while one cycle is being carried out.
3. The method as claimed in claim 1 , wherein source gas is one selected from the group consisting of Ta 2 O 5 , Al 2 O, HfO 2 , Ru, BST, SB, Pt, TiN, Ti, and TiO 2 .
4. The method as claimed in claim 1 , wherein reaction gas includes at least one selected from the group consisting of N 2 , O 2 , H 2 , NH 3 , N 2 O, cyclo-alkane such as C x H (2x) , and gas such as C x H (2x+2) , in which at least a part of alkane is replaced with F or Cl.
5. The method as claimed in claim 1 , wherein inert gas selected from the group consisting of He, Ne, Ar, Xe, and Kr is added to the reaction gas.
6. The method as claimed in claim 1 , wherein plasma power is adjusted below 1000 W when forming plasma.
7. The method as claimed in claim 1 , wherein, when forming the thin film, pressure of the process chamber is below atmospheric pressure, a substrate temperature is about 50 to 800° C., and a plasma reaction time is set in a range about 0.01 to 180 seconds.
8. The method as claimed in claim 1 , wherein, when forming the thin film, a purge time for purging source gas or reaction gas is set within 60 seconds.
9. The method as claimed in claim 1 , wherein the thin film includes a Mo source thin film.