Deposition method for wiring thin film

Abstract

An Al 3 Ti film having a large amount of dissolved Si is deposited on a semiconductor substrate to form a laminate with an Al wiring film, and heat treatment is performed at a temperature of at least 400° C., to thereby absorb excessive Si into the Al 3 Ti film and to so prevent the occurrence of Si nodules. By depositing Al film at a temperature of at least 400° C. at the time of depositing the Al wiring film on the Al 3 Ti film, excessive Si is caused to be absorbed in the Al 3 Ti film. Further, at the time of depositing a Ti film on the semiconductor substrate and depositing the Al wiring film, the Al film is deposited at a temperature of at least 400° C., there is reaction between the Ti film within the laminate, causing an Al 3 Ti film to be produced, and excessive Si is absorbed in the Al 3 Ti film produced.

1 : A method of forming a wiring film, the method comprising: 
 providing a substrate;    depositing a Ti layer over said substrate;    depositing an Al layer on said Ti layer using an Al—Si—Cu target;    annealing the substrate at a temperature of at least 400° C. after said depositing an Al layer to form an Al 3 Ti layer on said Ti layer and to promote absorption of Si from said Al layer into said Al 3 Ti layer; and    pattern etching said Al layer after said annealing.    
   
   
       2 : The method according to  claim 1 , further comprising forming an insulating layer between said substrate and said Ti layer.  
   
   
       3 : The method according to  claim 1 , further comprising depositing a TiN layer on said Al layer.  
   
   
       4 : The method according to  claim 1 , wherein a thickness of the deposited Al layer is 400-800 nm.  
   
   
       5 : The method according to  claim 2 , wherein said insulating layer is an SiO 2  layer or a BPSG layer.