A first polishing step is performed to remove {HEAD ~ a portion} of {TAIL ~ the silicon oxide layer} until a thickness of the remaining portion of the oxide layer reaches a predetermined thickness 
of
A first polishing step is performed to remove { HEAD ~ a portion } of { TAIL ~ the silicon oxide layer } until a thickness of the remaining portion of the oxide layer reaches a predetermined thickness
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH