According to the aspect of the invention, it is preferable that the wet etching be performed to a front surface of the substrate provided with {HEAD ~ the dry etching mask} in {TAIL ~ the wet etching process} 
in
According to the aspect of the invention , it is preferable that the wet etching be performed to a front surface of the substrate provided with { HEAD ~ the dry etching mask } in { TAIL ~ the wet etching process }
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL