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