Method of forming ruthenium film for metal wiring structure

Abstract

A method of depositing a ruthenium(Ru) thin film on a substrate in a reaction chamber, includes: (i) supplying a gas of a ruthenium precursor into the reaction chamber so that the gas of the ruthenium precursor is adsorbed onto the substrate, wherein the ruthenium precursor a ruthenium complex contains a non-cyclic dienyl; (ii) supplying an excited reducing gas into the reaction chamber to activate the ruthenium precursor adsorbed onto the substrate; and (iii) repeating steps (i) and (ii), thereby forming a ruthenium thin film on the substrate.

1 . A method of depositing a ruthenium(Ru) thin film on a substrate in a reaction chamber, comprising:
 (i) supplying a gas of a ruthenium precursor into the reaction chamber so that the gas of the ruthenium precursor is adsorbed onto the substrate, said ruthenium precursor a ruthenium complex containing a non-cyclic dienyl;   (ii) supplying an excited reducing gas into the reaction chamber to activate the ruthenium precursor adsorbed onto the substrate; and   (iii) repeating steps (i) and (ii), thereby forming a ruthenium thin film on the substrate.   
   
   
       2 . The method according to  claim 1 , wherein the ruthenium complex has a structure of Xa-Ru—Xb, wherein at least one of Xa or Xb is a non-cyclic dienyl. 
   
   
       3 . The method according to  claim 2 , wherein the non-cyclic dienyl is a non-cyclic pentadienyl. 
   
   
       4 . The method according to  claim 3 , wherein the non-cyclic pentadienyl has at least one side chain of C1-2 alkyl. 
   
   
       5 . The method according to  claim 4 , wherein the non-cyclic pentadienyl has two side chains of methyl. 
   
   
       6 . The method according to  claim 2 , wherein Xa is a non-cyclic dienyl, and Xb is a cyclic dienyl. 
   
   
       7 . The method according to  claim 6 , wherein Xa is a non-cyclic pentadienyl and Xb is a cyclopentadienyl. 
   
   
       8 . The method according to  claim 2 , wherein Xa and Xb are both non-cyclic pentadienyls. 
   
   
       9 . The method according to  claim 1 , wherein the excited reducing gas is generated by applying radio-frequency power to a reducing gas. 
   
   
       10 . The method according to  claim 9 , wherein the reducing gas is ammonia, hydrogen, or a mixture of nitrogen and hydrogen. 
   
   
       11 . The method according to  claim 9 , wherein the excited reducing gas is an ammonia or hydrogen plasma. 
   
   
       12 . The method according to  claim 1 , further comprising
 purging the ruthenium precursor gas from the reaction chamber after step (i); and   purging the excited reducing gas from the reaction chamber after step (ii).   
   
   
       13 . The method according to  claim 1 , wherein steps (i) and (ii) are repeated to form the ruthenium thin film having a thickness of no less than 0.5 nm but no more than 2.0 nm. 
   
   
       14 . The method according to  claim 1 , wherein steps (i) and (ii) are repeated to form the ruthenium thin film having a thickness of no less than 0.5 nm but no more than 2.0 nm. 
   
   
       15 . The method according to  claim 1 , wherein steps (i) and (ii) are repeated 50 times to 150 times. 
   
   
       16 . The method according to  claim 1 , further comprising providing a metal film before steps (i)-(iii) begin wherein the ruthenium thin film is formed on the metal film. 
   
   
       17 . The method according to  claim 16 , wherein the metal film is selected from the group consisting of WNC, WN, TaN, Ta, TaNC, TiN, Ti, Cu, Al, Co, and Ni. 
   
   
       18 . The method according to  claim 1 , wherein in step (i), the gas of the ruthenium precursor is a first gas, and step (i) further comprises supplying a second gas of another ruthenium precursor into the reaction chamber simultaneously with the first gas. 
   
   
       19 . The method according to  claim 1 , further comprising after repeating steps (i) and (ii) a give number of times:
 (iv) supplying a second gas of another ruthenium precursor into the reaction chamber so that the second gas of the other ruthenium precursor is adsorbed onto the substrate;   (v) supplying an excited reducing gas into the reaction chamber to activate the other ruthenium precursor adsorbed onto the substrate; and   (vi) repeating steps (iv) and (v), thereby forming a ruthenium thin film on the substrate.   
   
   
       20 . The method according to  claim 1 , further comprising after step (iii) forming a ruthenium thin film or ruthenium oxide thin film on the ruthenium thin film by CVD. 
   
   
       21 . The method according to  claim 1 , further comprising after step (iii) forming a copper film on the ruthenium thin film. 
   
   
       22 . The method according to  claim 21 , wherein the copper film is formed by supplying a gas of a copper precursor on the substrate, which is produced by CVD or ALD.