SEMICONDUCTOR PRESSURE SENSOR AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor pressure sensor which can be made compact without decreasing a sensitivity and its manufacturing method. SOLUTION: An SOI substrate including an insulating layer 6 of a buried oxide film inside is used as a semiconductor substrate 1. Part of an active layer 7 of the semiconductor substrate 1 constitutes a diaphragm part 2 of a sensor chip. Four piezoelectric resistors R1, R2, R3 and R4 are formed on the side of a main surface of the diaphragm part 2. A void part 4 which is formed hollow inside the semiconductor substrate 1 and can deflect the diaphragm part 2 is formed by etching and removing part of the insulating layer 6 between a supporting substrate 5 and the active layer 7 of the SOI substrate through an etching solution introduction hole 9.