{HEAD ~ A spin coating process} for controlling {TAIL ~ the mean thickness} of photoresist on the surface of a semiconductor wafer 
for controlling
{ HEAD ~ A spin coating process } for controlling { TAIL ~ the mean thickness } of photoresist on the surface of a semiconductor wafer
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH