| 摘要 |
PROBLEM TO BE SOLVED: To provide a thermosensitive flow rate sensor provided with a flow rate detection unit composed of single-crystal silicon, as well as capable of suppressing moisture absorption in an insulation film from underside and easily manufacturable, and a manufacturing method thereof.SOLUTION: In a thermosensitive flow rate sensor S1, a first nitride film 3 having higher impermeability than an insulation film 2 is provided between a semiconductor substrate 1 and the insulation film 2 so as to cover at least a flow rate detection unit 120. The accuracy of detecting the flow rate of a fluid by the flow rate detection unit 120 is thereby heightened, as compared with the case where the flow rate detection unit 120 is composed by adding impurity to polycrystalline silicon. In addition, even when there is the possibility of moisture getting into the insulation film 2 from the underside (semiconductor substrate 1 side) of the insulation film 2, the first nitride film 3 servers as a cover and the penetration of moisture into the insulation film 2 is prevented, making it possible to suppress a fluctuation in a sensor characteristic caused by moisture absorption in the insulation film 2.SELECTED DRAWING: Figure 2 |
