The method includes forming a first dry etching mask in a first masking region of a first surface of {HEAD ~ the substrate} in {TAIL ~ a first mask forming process} and performing a first dry etching process to remove a portion of the substrate in areas between the first dry etching mask after the first mask forming process 
in
The method includes forming a first dry etching mask in a first masking region of a first surface of { HEAD ~ the substrate } in { TAIL ~ a first mask forming process } and performing a first dry etching process to remove a portion of the substrate in areas between the first dry etching mask after the first mask forming process
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL 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