Method of manufacturing CMOS integrated circuit

Abstract

In a method of manufacturing a CMOS integrated circuit according to the present invention, a PSD step (step of forming P-type source/drain regions) is first carried out, and an NSD step (step of forming N-type source/drain regions) is thereafter carried out, in order to create a mixed structure of a silicide transistor and a non-silicide transistor. Thus, a step of depositing an oxide film on a substrate surface may be carried out only once, the oxide film can be removed by a single step of etching with hydrofluoric acid, and the operating characteristics of formed devices can be excellently maintained.

1 . A method of manufacturing a CMOS integrated circuit by forming isolated P and N wells on a surface layer region of a semiconductor substrate, forming gate electrodes on the respective wells, and thereafter sequentially carrying out:
 (1) a PSD step of forming P-type source and drain regions on the N well;   (2) an NSD step of forming N-type source and drain regions on the P well by depositing an oxide film on a surface of the substrate and selectively covering the N well with a resist film;   (3) a step of selectively removing the resist film, thereafter selectively covering the N well and the P well for a non-silicide transistor not subjected to silicide formation with a resist film, and then removing the oxide film from the N well and the P well constituting a silicide transistor; and   (4) forming a silicide on the gate electrodes and the source and drain regions of the N well and the P well from which the oxide film is removed.   
   
   
       2 . The method of manufacturing a CMOS integrated circuit according to  claim 1 , wherein
 the NSD step includes a step of implanting As ions for forming the N-type source and drain regions.   
   
   
       3 . The method of manufacturing a CMOS integrated circuit according to  claim 2 , employing hydrofluoric acid for selectively removing the oxide film. 
   
   
       4 . The method of manufacturing a CMOS integrated circuit according to  claim 1 , employing hydrofluoric acid for selectively removing the oxide film.