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