{HEAD ~ The method} 1, wherein etching {TAIL ~ the second insulating layer} is stopped at the etch stopper and the surface of the contact plug 
wherein etching
{ HEAD ~ The method } 1 , wherein etching { TAIL ~ the second insulating layer } is stopped at the etch stopper and the surface of the contact plug
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH