Method of manfacturing semiconductor device
View Patent ↗A post-CMP cleaning process of a copper layer is to be performed as follows. An alkaline aqueous solution, a polycarboxylic acid, BTA, and an alkaline aqueous solution are sequentially brought into contact with a primary surface of a silicon substrate over which the copper layer is provided.
1. A method of manufacturing a semiconductor device, comprising:
forming a copper-containing metal layer over a semiconductor substrate;
polishing said copper-containing metal layer; and
cleaning a surface of said copper-containing metal layer after polishing said copper-containing metal layer;
wherein said cleaning the surface of said copper-containing metal layer includes:
a first process including bringing a polycarboxylic acid into contact with a primary surface of said semiconductor substrate over which said copper-containing metal layer is provided;
a second process including bringing a reduced water into contact with said primary surface after said first process;
a third process including bringing benzotriazole or a derivative thereof with said primary surface after said second process; and
a fourth process including bringing an alkaline aqueous solution into contact with said primary surface after said third process.
2. The method according to claim 1 ,
wherein said cleaning the surface of said copper-containing metal layer further includes bringing an alkaline aqueous solution into contact with said primary surface before said first process.
3. The method according to claim 2 ,
wherein said bringing the alkaline aqueous solution into contact with said primary surface before said first process includes employing an alkali reduced water as said alkaline aqueous solution.
4. The method according to claim 1 ,
wherein said first process includes employing oxalic acid as said polycarboxylic acid.
5. The method according to claim 1 ,
wherein said second process includes employing an alkali reduced water as said reduced water.
6. The method according to claim 5 ,
wherein said alkali reduced water has a pH value equal to or higher than 7.4 and equal to or lower than 9.5.
7. The method according to claim 1 ,
wherein said reduced water brought into contact in said second process and said alkaline aqueous solution brought into contact in said fourth process are of a same type.
8. The method according to claim 7 ,
wherein said reduced water brought into contact in said second process and said alkaline aqueous solution brought into contact in said fourth process are both an alkali reduced water.
9. The method according to claim 1 , further comprising:
forming an insulating interlayer over said semiconductor substrate before said forming the copper-containing metal layer over the semiconductor substrate; and
selectively removing a predetermined region of said insulating interlayer thus to form a concave;
wherein said forming the copper-containing metal layer over the semiconductor substrate includes forming said copper-containing metal layer so as to fill in said concave; and
said polishing said copper-containing metal layer includes removing said copper-containing metal layer formed outside said concave, to thereby expose a surface of said insulating interlayer.