Patent ID: 6887734

Claim:
A method of manufacturing a semiconductor pressure sensor on a monocrystal silicon substrate in which the face direction of one face corresponds to the (110)-face, the method comprising: disposing an etching mask at the one face side of the monocrystal silicon substrate, wherein the etching mask has a cross-shaped opening portion at which a first area extending along the <110> crystal axis direction and a second area extending along the <100> crystal axis direction cross each other, and an area of an opening portion in an overlap area between the first area and the second area in the opening portion is set to be smaller than an area of a diaphragm to be formed in the substrate; and forming a recess portion on the monocrystal silicon substrate by conducting anisotropic etching from the one face of the monocrystal silicon substrate and also forming a pressure-receiving diaphragm at the bottom surface side of the recess portion in the monocrystal silicon substrate.