Subsequent layers are spun onto the top surface of prior layers and exposed, and upon completion of the succession of layers each defining corresponding levels of the desired structure, the layers are all developed at {HEAD ~ the same time} leaving {TAIL ~ the three dimensional structure} 
leaving
Subsequent layers are spun onto the top surface of prior layers and exposed , and upon completion of the succession of layers each defining corresponding levels of the desired structure , the layers are all developed at { HEAD ~ the same time } leaving { TAIL ~ the three dimensional structure }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL