{TAIL ~ A wet etching process} is performed to remove the first un etched portion of {HEAD ~ the substrate} after the mask removing process, thereby forming the piezoelectric resonator element 
{ TAIL ~ A wet etching process } is performed to remove the first un etched portion of { HEAD ~ the substrate } after the mask removing process , thereby forming the piezoelectric resonator element
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH