SEMICONDUCTOR SENSOR AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor sensor and its manufacturing method capable of reducing the cost, having strong mechanical strength, and capable of making high-precision measurement. SOLUTION: In Fig. 2 (a), an impurity diffusion area 2 is formed as a lower electrode on the surface of a Si substrate, then a plurality of trenches are formed in the impurity diffusion area 2 by a dry etching method. In Fig. 2 (b), the Si substrate 1 is annealed in a high-temperature state so that the surface is not oxidized. When annealing is applied, Si flows to minimize the surface area, and a cavity section 6 is formed in the Si substrate 1. In Fig. 2 (c), a high-concentration impurity diffusion area 7 is formed as an upper electrode on a diaphragm section 10. In Fig. 2 (d), an insulating layer 8 is formed on the surface of the Si substrate 1, and metal wiring 9 is formed. Since a plurality of trenches are formed in the impurity diffusion area 2 and annealing is applied, a pressure reference chamber and the diaphragm section can be simultaneously formed.