Patent ID: 8703517

Claim:
A manufacturing method of a semiconductor device comprising: preparing a substrate including single crystalline silicon; forming a reformed layer that continuously extends in the substrate, the forming the reformed layer including polycrystallizing a portion of the single crystalline silicon by irradiating the substrate with a pulsed laser beam while moving a focal point of the laser beam in the substrate; and removing the reformed layer by wet etching, wherein the semiconductor device includes a sensor having a diaphragm, wherein the forming the reformed layer and the removing the reformed layer are applied to forming the diaphragm in the substrate, wherein the forming the reformed layer includes forming the reformed layer along an interface between the diaphragm and a removal region under the diaphragm, and wherein the removing the reformed layer includes hollowing out the removal region by removing the reformed layer by wet etching, the diaphragm thereby being exposed to the outside.