Substrate processing method and substrate processing apparatus
A substrate processing method includes forming a carbon film on a substrate by plasma CVD using a processing gas including a carbon-containing gas; and performing a plasma post-processing on the formed carbon film, thereby reducing film stress of the carbon film by plasma of the processing gas including helium gas or a mixture of helium gas and argon gas but not including hydrogen.
1 . A substrate processing method comprising:
forming a carbon film on a substrate by plasma CVD using a first processing gas including a carbon-containing gas; and
performing a plasma post-processing on the carbon film formed at the forming, thereby reducing film stress of the carbon film by plasma generated from a second processing gas including helium gas or a mixture of helium gas and argon gas but not including hydrogen,
wherein the forming of the carbon film and the performing of the plasma post-processing are carried out using capacitively-coupled plasma generated by forming a radio-frequency electric field between a lower electrode serving as a stage on which the substrate is mounted, and an upper electrode facing the lower electrode, and
the performing of the plasma post-processing is carried out by applying a radio-frequency power with a frequency of 13.56 MHz or less only to the lower electrode.
2 . The substrate processing method according to claim 1 , wherein when a flow rate ratio of helium gas to a total of helium gas and argon gas is represented as helium gas flow rate/(helium gas flow rate+argon gas flow rate)×100%, the performing of the plasma post-processing is carried out at the flow rate ratio of 80% or higher.
3 . The substrate processing method according to claim 1 , wherein the forming of the carbon film is carried out using, as the first processing gas, a gas including the carbon-containing gas and a diluent gas that includes a noble gas.
4 . The substrate processing method according to claim 1 , wherein the forming of the carbon film and the performing of the plasma post-processing are continuously carried out in an identical processing container.
5 . The substrate processing method according to claim 1 , wherein the forming of the carbon film is carried out by applying a first radio-frequency power with a frequency of 100 MHz or higher to the lower electrode or the upper electrode and applying a second radio-frequency power with a frequency of 13.56 MHz to the lower electrode.
6 . The substrate processing method according to claim 1 , wherein the performing of the plasma post-processing is carried out at a pressure of 1.33 to 13.3 Pa.
7 . The substrate processing method according to claim 1 , wherein the carbon film is used as a hard mask.
8 . The substrate processing method according to claim 1 , wherein after the performing of the plasma post-processing, the film stress of the carbon film is not increased when the carbon film is subjected to annealing in a range of 200° C. and 450° C.
9 . The substrate processing method according to claim 1 , further comprising:
after the performing of the plasma post-processing, annealing the carbon film at a temperature in a range of 200° C. and 450° C.
10 . The substrate processing method according to claim 1 , wherein the performing of the plasma post-processing is carried out at a temperature of 200° C. or less.
11 . The substrate processing method according to claim 1 , wherein a flow rate of the second processing gas during the plasma post-processing is set to be between 10 and 500 sccm.