Method for Polishing Semiconductor Layers

Abstract

The aqueous polishing method is useful for polishing semiconductor substrates including a TEOS layer and a SiOC layer. The method removes TEOS with a polishing composition having 0.05 to 50 weight percent abrasive, 0.001 to 2 weight percent lambda type carrageenan and an anionic surfactant. The lambda type carrageenan has a concentration useful for accelerating TEOS removal rate; and the anioinic surfactant is useful for suppressing removal rate of the SiOC layer.

1 . A method of polishing a semiconductor substrate, the semiconductor substrate including a TEOS layer and a SiOC layer including steps as follows:
 polishing the semiconductor substrate with an aqueous polishing composition to remove TEOS from the semiconductor substrate, the composition including 0.05 to 50 weight percent silica abrasive, 0.001 to 2 weight percent lambda type carrageenan and an anionic surfactant;   removing TEOS from the semiconductor substrate with the lambda type carrageenan increasing TEOS removal rate of the TEOS layer and the anioic surfactant being useful for suppressing removal rate of the SiOC layer.   
   
   
       2 . The method of  claim 1  wherein the polishing the semiconductor substrate occurs with the aqueous polishing composition having 0.1 to 50 weight percent silica abrasive and 0.01 to 1.5 weight percent lambda type carrageenan. 
   
   
       3 . The method of  claim 1  wherein the polishing the semiconductor substrate occurs with the aqueous polishing composition having 0.2 to 50 weight percent silica abrasive and 0.05 to 1 weight percent lambda type carrageenan. 
   
   
       4 . The method of  claim 3  wherein the polishing the semiconductor substrate occurs with the aqueous polishing composition including a benzotriazole corrosion inhibitor.