Workpiece cutting method and workpiece holding tool

The present invention provides chemical mechanical polishing compositions and methods for polishing a substrate comprising silicon dioxide and silicon nitride, which provide selective removal of SiN relative to silicon oxide (e.g., PETEOS) on patterned wafers. In one embodiment, a CMP method comprises abrading a surface of a substrate comprising SiN and silicon oxide with a CMP composition to remove at least some SiN therefrom. The CMP composition comprises, consists essentially of, or consists of a particulate abrasive (e.g., ceria) suspended in an aqueous carrier and containing a cationic polymer bearing pendant quaternized nitrogen-heteroaromatic moieties, wherein the composition has a pH of greater than about 3. 本发明提供用于抛光包含二氧化硅及硅氮化物的基板的化学机械抛光组合物及方法，其在经图案化的晶片上提供相对于硅氧化物(例如，PETEOS)的对SiN的选择性移除。在个实施方案中，CMP方法包括用CMP组合物研磨包含SiN及硅氧化物的基板表面以从其移除至少些SiN。该CMP组合物包含以下物质、基本上由以下物质组成、或者由以下物质组成：悬浮于水性载体中的粒状研磨剂(例如，氧化铈)，且含有带有经季铵化的氮?杂芳族悬垂部分的阳离子型聚合物，其中该组合物的pH大于3。