Semiconductor pressure sensor and method of manufacturing the same

摘要

A semiconductor pressure sensor includes a single crystal silicon substrate; a diaphragm formed in the single crystal silicon substrate by etching the single crystal silicon substrate from a back surface side thereof; four diaphragm side walls enclosing the diaphragm; and a bridge circuit formed on a surface of the single crystal silicon substrate, the bridge circuit including a lead conductor and a strain gauge resistor. The bridge circuit is configured to detect a pressure applied to the semiconductor pressure sensor based on a change in an output value of the bridge circuit that corresponds to an amount of flexure produced in the diaphragm by the pressure. The diaphragm has a plane orientation in a (110) plane and a parallelogram in-plane shape. The four diaphragm side walls have a plane orientation in a (111) plane and form two pairs of parallel and opposite surfaces.