Afterward, {HEAD ~ the dielectric layer} 10 is removed again from {TAIL ~ the upper region} of the trench, i.e., above the polysilicon layer 11, from the side walls of the trench 5 
is removed from
Afterward , { HEAD ~ the dielectric layer } 10 is removed again from { TAIL ~ the upper region } of the trench , i.e. , above the polysilicon layer 11 , from the side walls of the trench 5
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH