A quick wet etching process is performed to remove a portion of {HEAD ~ the remaining first oxide} located on the top of the gate structure and on {TAIL ~ the substrate} 
A quick wet etching process is performed to remove a portion of { HEAD ~ the remaining first oxide } located on the top of the gate structure and on { TAIL ~ the substrate }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL