{HEAD ~ An electrical insulation} is formed between the first region and {TAIL ~ the second region} of the semiconductor layer 
is formed between
{ HEAD ~ An electrical insulation } is formed between the first region and { TAIL ~ the second region } of the semiconductor layer
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH