A silicon material layer is then formed in {HEAD ~ the trench} using {TAIL ~ an epitaxial deposition} 
using
A silicon material layer is then formed in { HEAD ~ the trench } using { TAIL ~ an epitaxial deposition }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL