In the preoxidation cleaning step, {HEAD ~ a solution} containing NH4F, HF, and {TAIL ~ H2O}, a standard solution containing NH4OH, H2O2, and H2O, and HF are used 
In the preoxidation cleaning step , { HEAD ~ a solution } containing NH4F , HF , and { TAIL ~ H2O } , a standard solution containing NH4OH , H2O2 , and H2O , and HF are used
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH