Abstract: A method for planarizing a surface in an integrated circuit manufacturing process provides a first film of a first material over a non-uniform surface, such as a surface including isolation trenches. The first material includes, for example, a polysilicon layer to be used to form floating gates in a non-volatile memory integrated circuit. A second film, which is a sacrificial film formed using a second material, such as silicon oxide, is then provided over the first film. Partial removal of the second film is carried out using chemical mechanical polishing until a portion of the first film is exposed using a first slurry that is selective to the first material. Thereafter, the remaining layer of the second film is removed, along with planarization of the surface, using a second slurry that is less selective, i.e., has a selectivity of the first film to the second film that is less than a predetermine value (e.g., 2:1).

Abstract: A chemical mechanical polishing (CMP) method is disclosed in which a new polishing pad is broken-in and conditioned into a steady operating state while using a silica (SiO2) based CMP slurry and where the broken-in and conditioned pad is afterwards used for polishing patterned workpieces (e.g., semiconductor wafers) with a ceria (CeO2) based CMP slurry. The approach shortens break-in time and appears to eliminate a first wafer effect usually seen following break-in with ceria-based CMP slurries.

Abstract: A chemical mechanical polishing (CMP) method is disclosed in which a torque-based end-point algorithm is used to determine when polishing should be stopped. The end-point algorithm is applicable to situations where a ceria (CeO2) based CMP slurry is used for further polishing, pre-patterned and pre-polished workpieces (e.g., semiconductor wafers) which have a high friction over-layer (e.g., HDP-oxide) and a comparatively, lower friction and underlying layer of sacrificial pads (e.g., silicon nitride pads). A mass production wise, reliable and consistent signature point in the friction versus time waveform of a torque-representing signal is found and used to trigger an empirically specified duration of overpolish. A database may be used to define the overpolish time as a function of one or more relevant parameters.