Method of manufacturing 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 trench in an insulating layer over a semiconductor substrate;
forming a copper-containing metal layer over said insulating layer and inside said trench;
polishing said copper-containing metal layer so as to expose said insulating layer; and
cleaning a surface of said copper-containing metal layer and of said insulating layer, after polishing said copper-containing metal layer;
wherein said cleaning said surface of said copper-containing metal layer and of said insulating layer includes:
a first process including removing copper ion and copper oxide;
a second process including reducing, after said first process, said copper ion and said copper oxide remaining unremoved through said first process, thereby giving copper;
a third process including enclosing with an organic layer, after said second process, said copper given through said second process; and
a fourth process including giving a negative surface potential to said organic layer and to said insulating layer, after said third process.
2. The method according to claim 1 , wherein said cleaning the surface of said copper-containing metal layer and of said insulating layer further includes removing a slurry.
3. The method according to claim 1 , wherein said first process includes bringing polycarboxylic acid into contact with the surface of said copper-containing metal layer and of said insulating layer; the second process includes bringing reduced water into contact with the surface of said copper-containing metal layer and of said insulating layer; the third process includes bringing benzotriazole or a derivative thereof into contact with the surface of said copper-containing metal layer and of said insulating layer; and the fourth process includes bringing an alkaline aqueous solution into contact with the surface of said copper-containing metal layer and of said insulating layer.
4. The method according to claim 2 , wherein said first process includes bringing a polycarboxylic acid into contact with the surface of said copper-containing metal layer and of said insulating layer; the second process includes bringing a reduced water into contact with the surface of said copper-containing metal layer and of said insulating layer; the third process includes bringing benzotriazole or a derivative thereof into contact with the surface of said copper-containing metal layer and of said insulating layer; the fourth process includes bringing an alkaline aqueous solution into contact with the surface of said copper-containing metal layer and of said insulating layer; and said removing the slurry includes bringing an alkaline aqueous solution into contact with the surface of said copper-containing metal layer and of said insulating layer.
5. The method according to claim 3 , 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 4 , wherein said second process includes employing an alkali reduced water as said reduced water; and said fourth process and said removing the slurry include employing an alkali reduced water as said alkaline aqueous solution.