Substrate processing method and substrate processing apparatus

Abstract

A substrate processing method makes it possible to fill interconnect recesses, such as trenches, with a defect-free interconnect material by carrying out electroplating directly on a surface of a ruthenium film as a barrier layer. The substrate processing method comprises: providing a substrate having interconnect recesses formed in a substrate surface and having a ruthenium film formed in the entire substrate surface including interior surfaces of the interconnect recesses; keeping the substrate surface in contact with a plating solution for a predetermined time to adsorb an additive in the plating solution onto the ruthenium film, and then carrying out electroplating to form a conductive film on a surface of the ruthenium film.

1 . A substrate processing method comprising:
 providing a substrate having interconnect recesses formed in a substrate surface and having a ruthenium film formed in the entire substrate surface including interior surfaces of the interconnect recesses;   keeping the substrate surface in contact with a plating solution for a predetermined time to adsorb an additive in the plating solution onto the ruthenium film; and then carrying out electroplating to form a conductive film on a surface of the ruthenium film.   
   
   
       2 . The substrate processing method according to  claim 1 , wherein the conductive film is composed of copper or a copper alloy. 
   
   
       3 . The substrate processing method according to  claim 2 , wherein the plating solution contains a copper ion, a sulfate ion and the additive. 
   
   
       4 . The substrate processing method according to  claim 1 , wherein the predetermined time for keeping the substrate surface in contact with the plating solution prior to the electroplating is not less than 0.5 second and not more than 60 seconds. 
   
   
       5 . The substrate processing method according to  claim 1 , wherein the predetermined time for keeping the substrate surface in contact with the plating solution prior to the electroplating is not less than 0.1 second and not more than 20 seconds. 
   
   
       6 . The substrate processing method according to  claim 1 , wherein the predetermined time for keeping the substrate surface in contact with the plating solution prior to the electroplating is not less than 0.1 second and not more than 5 seconds. 
   
   
       7 . A substrate processing method comprising:
 providing a substrate having interconnect recesses formed in a substrate surface and having a ruthenium film formed in the entire substrate surface including interior surfaces of the interconnect recesses;   keeping the substrate surface in contact with a plating solution for a predetermined time to adsorb an additive in the plating solution onto the ruthenium film, and then carrying out first electroplating to form an initial conductive film, which covers the entire interior surfaces of the interconnect recesses, on the surface of the ruthenium film;   cleaning and drying the substrate surface; and then   carrying out second electroplating to allow a conductive film to further grow on a surface of the initial conductive film.   
   
   
       8 . The substrate processing method according to  claim 7 , wherein the first electroplating and the second electroplating are carried out by using the same plating solution. 
   
   
       9 . The substrate processing method according to  claim 7 , wherein the predetermined time for keeping the substrate surface in contact with the plating solution prior to the first electroplating is not less than 5 seconds. 
   
   
       10 . A substrate processing apparatus for forming a conductive film on a surface of a substrate by electroplating, the substrate having interconnect recesses formed in the substrate surface and having a ruthenium film formed in the entire substrate surface including interior surfaces of the interconnect recesses, said apparatus comprising:
 a measurement section for measuring time that has elapsed since the substrate surface has been brought into contact with a plating solution.   
   
   
       11 . The substrate processing apparatus according to  claim 10 , wherein the measurement section is comprised of a position detector for detecting the position of the substrate or a substrate holder, or a substrate-solution contact detector for detecting contact of the substrate with the plating solution. 
   
   
       12 . The substrate processing apparatus according to  claim 11 , wherein the substrate-solution contact detector is comprised of an optical sensor, a pressure sensor, a conductivity sensor, a temperature sensor or an ultrasonic sensor, or a combination thereof.