The combination of {HEAD ~ the silicon oxide layer} and the silicon layer comprise, in turn, {TAIL ~ a composite SRO layer} 
The combination of { HEAD ~ the silicon oxide layer } and the silicon layer comprise , in turn , { TAIL ~ a composite SRO layer }
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL