{HEAD ~ A rotating or vibrating disk} or pad is moved relative to {TAIL ~ the semiconductor wafer surface} in the presence of a chemical mechanical polishing slurry 
is moved relative to
{ HEAD ~ A rotating or vibrating disk } or pad is moved relative to { TAIL ~ the semiconductor wafer surface } in the presence of a chemical mechanical polishing slurry
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH