Alternatively, {HEAD ~ a silicon substrate} may be used instead of the substrate and {TAIL ~ the oxide layer} 
Alternatively , { HEAD ~ a silicon substrate } may be used instead of the substrate and { TAIL ~ the oxide layer }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL