Method for forming ti film and tin film, contact structure, computer readable storage medium and computer program

Abstract

A cleaning process is performed on the surface of a nickel silicide film serving as an underlayer. Then, a Ti film is formed to have a film thickness of not less than 2 nm but less than 10 nm by CVD using a Ti compound gas. Then, the Ti film is nitrided. Then, a TiN film is formed on the Ti film thus nitrided, by CVD using a Ti compound gas and a gas containing N and H.

1 . A film formation method for forming a Ti film and a TiN film on an underlayer comprising a metal silicide film disposed on a substrate, the film formation method comprising:
 cleaning a surface of the underlayer by a process using a chemical reaction or plasma;   forming a Ti film to have a film thickness of not less than 2 nm but less than 10 nm on the underlayer by a CVD process of supplying TiCl 4  gas at a flow rate of 0.001 to 0.02 L/min, H 2  gas at a flow rate of 1.5 to 6 L/min, and Ar gas at a flow rate of 0.3 to 3 L/min, and applying an RF (radio frequency) power at a power value of 300 to 2,000 W to generate a first plasma from these gases thus supplied, while setting a process temperature of 300 to 500° C. and a process pressure of 260 to 1,333 Pa on the substrate;   nitriding the Ti film by a nitridation process of supplying NH 3  gas at a flow rate of 0.5 to 3 L/min, H 2  gas at a flow rate of 1.5 to 6 L/min, and Ar gas at a flow rate of 0.3 to 3 L/min, and applying an RF power at a power value of 300 to 1,200 W to generate a second plasma from these gases thus supplied, while setting a process temperature of 300 to 500° C. and a process pressure of 260 to 1,333 Pa on the substrate; and   forming a TiN film on the Ti film thus nitrided, by a CVD process using a Ti compound gas, N 2  gas, and NH 3  gas.   
   
   
       2 . The method according to  claim 1 , wherein said cleaning a surface of the underlayer comprises performing sputter etching on the surface of the underlayer by use of inductively coupled plasma of Ar gas. 
   
   
       3 . The method according to  claim 1 , wherein said cleaning a surface of the underlayer comprises causing a chemical reaction on the surface of the underlayer by supplying HF gas and NH 3  gas onto the surface of the underlayer. 
   
   
       4 . The method according to  claim 3 , wherein said cleaning a surface of the underlayer further comprises subjecting the substrate to a heat process after said causing a chemical reaction. 
   
   
       5 . The method according to  claim 1  wherein the CVD process for said forming a Ti film comprises supplying TiCI 4  gas at a flow rate of 0.01 to 0.08 L/min, N 2  gas at a flow rate of 0.05 to 3 L/min, and NH 3  at a flow rate of 0.05 to 0.3 L/min, without applying an RF power, while setting a process temperature of 300 to 500° C. and a process pressure of 40 to 670 Pa on the substrate. 
   
   
       6 . The method according to  claim 1 , wherein the metal silicide is silicide of a metal selected from the group consisting of Ni, Co, Mo, W, Pt, and Pd. 
   
   
       7 . A film formation method for forming a Ti film and a TiN film on an underlayer comprising a metal silicide film disposed on a substrate, the film formation method comprising:
 cleaning a surface of the underlayer by a process using a chemical reaction or plasma;   forming a Ti film to have a film thickness of not less than 2 nm but less than 10 nm on the underlayer by a CVD process of supplying TiCI 4  gas at a flow rate of 0.001 to 0.02 L/min, H 2  gas at a flow rate of 1.5 to 6 L/min, and Ar gas at a flow rate of 0.3 to 3 L/min, and applying an RF (radio frequency) power at a power value of 300 to 2000 W to generate a first plasma from these gases thus supplied, while setting a process temperature of 300 to 500° C. and a process pressure of 260 to 1,333 Pa on the substrate;   nitriding the Ti film by a nitridation process of supplying NH 3  gas at a flow rate of 0.5 to 3 L/min, H 2  gas at a flow rate of 1.5 to 6 L/min, and Ar gas at a flow rate of 0.3 to 3 L/min, and applying an RF power at a power value of 300 to 1,200 W to generate a second plasma from these gases thus supplied, while setting a process temperature of 300 to 500° C. and a process pressure of 260 to 1,333 Pa on the substrate; and   forming a TiN film on the Ti film thus nitrided, by alternately repeating, a plurality of times, a first step of supplying a Ti compound gas, N 2  gas, and NH 3  gas, and a second step of supplying N 2  gas, and NH 3  gas without supplying the Ti compound gas.   
   
   
       8 . The method according to  claim 7 , wherein said cleaning a surface of the underlayer comprises performing sputter etching on the surface of the underlayer by use of inductively coupled plasma of Ar gas. 
   
   
       9 . The method according to  claim 7 , wherein said cleaning a surface of the underlayer comprises causing a chemical reaction on the surface of the underlayer by supplying HF gas and NH 3  gas onto the surface of the underlayer. 
   
   
       10 . The method according to  claim 9 , wherein said cleaning a surface of the underlayer further comprises subjecting the substrate to a heat process after said causing a chemical reaction. 
   
   
       11 . The method according to  claim 7 , wherein the first step of said forming a Ti film comprises supplying TiCl 4  gas at a flow rate of 0.01 to 0.08 L/min, N 2  gas at a flow rate of 0.05 to 3 L/min, and NH 3  at a flow rate of 0.05 to 0.3 L/min, without applying an RF power, while setting a process temperature of 300 to 500° C. and a process pressure of 40 to 670 Pa on the substrate. 
   
   
       12 . The method according to  claim 7 , wherein the metal silicide is silicide of a metal selected from the group consisting of Ni, Co, Mo, W, Pt, and Pd.