Successive etching processes form {HEAD ~ a plurality} of partially etched cavities extending from {TAIL ~ a front surface} of the cap wafer into the cap wafer  
Successive etching processes form { HEAD ~ a plurality } of partially etched cavities extending from { TAIL ~ a front surface } of the cap wafer into the cap wafer
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH