Method of manufacturing semiconductor device and substrate processing apparatus

Abstract

Provided is a technique of adjusting a work function. A method of manufacturing a semiconductor device includes forming a film having a predetermined thickness and containing a first metal element, carbon and nitrogen on a substrate by: (a) forming a first layer containing the first metal element and carbon by supplying a metal-containing gas containing the first metal element and a carbon-containing gas to the substrate M times and (b) forming a second layer containing the first metal element, carbon and nitrogen by supplying a nitrogen-containing gas to the substrate having the first layer formed thereon N times to nitride the first layer, wherein M and N are selected in a manner that a work function of the film has a predetermined value (where M and N are natural numbers).

What is claimed is: 
     
         1 . A method of manufacturing a semiconductor device, comprising forming a film having a predetermined thickness and containing a first metal element, carbon and nitrogen on a substrate by: (a) forming a first layer containing the first metal element and carbon by supplying a metal-containing gas containing the first metal element and a carbon-containing gas to the substrate M times and (b) forming a second layer containing the first metal element, carbon and nitrogen by supplying a nitrogen-containing gas to the substrate having the first layer formed thereon N times to nitride the first layer, wherein M and N are selected in a manner that a work function of the film has a predetermined value (where M and N are natural numbers). 
     
     
         2 . The method of  claim 1 , wherein the first metal element comprises one selected from the group consisting of tantalum, cobalt, tungsten, molybdenum, ruthenium, yttrium, lanthanum, zirconium and hafnium. 
     
     
         3 . The method of  claim 1 , wherein the metal-containing gas comprises one selected from the group consisting of TiCl 4  and TaCl 4 . 
     
     
         4 . The method of  claim 1 , wherein the carbon-containing gas comprises Hf[C 5 H 4 (CH 3 )] 2 (CH 3 ) 2 . 
     
     
         5 . The method of  claim 1 , wherein the carbon-containing gas comprises a second metal element different from the first metal element. 
     
     
         6 . The method of  claim 5 , wherein the second metal element comprises hafnium. 
     
     
         7 . The method of  claim 1 , wherein the work function of the film is increased by selecting M greater than N. 
     
     
         8 . The method of  claim 1 , wherein a concentration of carbon in the film is controlled by selecting M and N to adjust the work function of the film to be the predetermined value. 
     
     
         9 . A method of manufacturing a semiconductor device, comprising: forming a metal film containing carbon and nitrogen in a predetermined ratio on a substrate by: (a) forming a first layer containing a metal element and one of carbon and nitrogen M times and (b) forming a second layer containing the metal element, nitrogen and carbon N times, wherein (a) and (b) are alternately performed L times (where M, N and L are natural numbers). 
     
     
         10 . A substrate processing apparatus comprising:
 a process chamber configured to accommodate a substrate;   a metal-containing gas supply system configured to supply a metal-containing gas containing a metal element to the substrate in the process chamber;   a carbon-containing gas supply system configured to supply a carbon-containing gas to the substrate in the process chamber;   a nitrogen-containing gas supply system configured to supply a nitrogen-containing gas to the substrate in the process chamber; and   a control unit configured to control the metal-containing gas supply system, the carbon-containing gas supply system and the nitrogen-containing gas supply system to form a film having a predetermined thickness and containing the metal element, carbon and nitrogen on the substrate by: (a) forming a first layer containing the metal element and carbon by supplying the metal-containing gas and the carbon-containing gas to the substrate M times; and (b) forming a second layer containing the metal element, carbon and nitrogen by supplying the nitrogen-containing gas to the substrate having the first layer formed thereon N times to nitride the first layer, wherein M and N are selected in a manner that a work function of the film has a predetermined value (where M and N are natural numbers).