申请人:HITACHI CHEMICAL COMPANY, LTD.
公开号:US20150031205A1
公开(公告)日:2015-01-29
Provided is a polishing method including a step of preparing a substrate having (
1
) silicon nitride as a stopper, and to a direction of a surface subjected to polishing from the stopper, (
2
) at least a portion of a wiring metal, and (
3
) at least a portion of an insulating material; a step of supplying a CMP slurry, and thereby polishing the (
2
) wiring metal and (
3
) insulating material on the direction of the surface subjected to polishing; and a step of stopping polishing before the (
1
) silicon nitride is exposed and completely removed, in which method the CMP slurry contains (A) a copolymer of (a) a monomer that is anionic and does not contain a hydrophobic substituent and (b) a monomer containing a hydrophobic substituent; (B) an abrasive grain; (C) an acid; (D) an oxidizing agent; and (E) a liquid medium, the component (B) has a zeta potential of +10 mV or more in the CMP slurry, and the copolymerization ratio (a):(b) of the component (A) is 25:75 to 75:25 as a molar ratio, with the pH being 5.0 or less. Through this method, an interlayer insulating film and a stopper can be polished at a high selectivity while metal and the interlayer insulating film are removed at high polishing rates, and thus a semiconductor device having high dimensional accuracy can be produced.
提供了一种抛光方法,包括以下步骤:准备基板,该基板具有(1)硅氮化物作为停止层,在从停止层到抛光表面的方向上具有(2)至少一部分的布线金属和(3)至少一部分的绝缘材料;供应CMP研磨液,并在抛光表面的方向上抛光(2)布线金属和(3)绝缘材料;在(1)硅氮化物暴露并完全去除之前停止抛光。该方法中,CMP研磨液含有(A)一种共聚物,其中包括(a)一种带负电且不含疏水取代基的单体和(b)一种含有疏水取代基的单体;(B)磨料颗粒;(C)酸;(D)氧化剂;和(E)液体介质。组分(B)在CMP研磨液中具有+10 mV或更高的ζ电位,组分(A)的共聚比(a):(b)为25:75至75:25的摩尔比,pH值为5.0或更低。通过该方法,可以在高选择性下抛光互层绝缘膜和停止层,同时以高抛光速率去除金属和互层绝缘膜,从而生产具有高尺寸精度的半导体器件。