etching the layer to be processed with any one of Xe, Kr, a mixed gas of Ar and at least one of Xe and Kr, and a mixed gas of Xe and {HEAD ~ Kr} is used as {TAIL ~ a dilution gas} using the remaining film of the resist pattern as mask, 
etching the layer to be processed with any one of Xe , Kr , a mixed gas of Ar and at least one of Xe and Kr , and a mixed gas of Xe and { HEAD ~ Kr } is used as { TAIL ~ a dilution gas } using the remaining film of the resist pattern as mask ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH