Sensor element

1. A sensor element comprising:

a first substrate in which a diaphragm is configured on a main surface;

a second substrate which is provided on the side opposite to the diaphragm of said first substrate;

a cavity which is provided just below the diaphragm of said first substrate;

a fitting portion which is provided at a bonding position between said first substrate and said second substrate for airtight sealing of the cavity; and

a bump portion which is provided at the fitting portion, and protects a fitted state between said first substrate and said second substrate, the bump portion extending from the first substrate and not contacting the second substrate.

2. The sensor element of claim 1 ,

wherein the bump portion is provided with a protective layer on the side opposite to the diaphragm of said first substrate, the bump portion being formed by providing a bump on the fitting portion.

3. The sensor element of claim 2 ,

wherein said protective layer is selected from a material having a function for obtaining a getter effect to maintain airtightness of the cavity by absorbing discharged gas in the cavity.

4. The sensor element of claim 2 ,

wherein said protective layer is selected from a thin film material containing at least any of aluminum (Al), nickel (Ni), silicon (Si), silicon nitride film, silicon oxide film, and diamond-like carbon (DLC); alternatively, said protective layer is selected from a thin film material containing at least any of zirconium (Zr), titanium (Ti), hafnium (Hf), cerium (Ce), thorium (Th), and magnesium oxide (MgO), each of which being capable of obtaining a gettering effect.

5. The sensor element of claim 1 ,

wherein the bump portion is integrally formed with said first substrate.

6. The sensor element of claim 1 ,

wherein said second substrate is provided with groove processing for airtight sealing of the bump portion.

7. The sensor element of claim 1 ,

wherein the bump portion is formed by providing a bump on the surface opposite to the diaphragm of said first substrate.

8. The sensor element of claim 1 ,

wherein said second substrate is provided with groove processing in a method that obtains a cross-sectional structure processed along the shape of a facing die.

9. The sensor element of claim 1 ,

wherein said first substrate is configured by an active layer, an embedded oxide film, and a supporting substrate.

10. The sensor element of claim 1 ,

wherein said second substrate is configured by a base made of a material having the same quality as said first substrate or a glass wafer.

11. The sensor element of claim 1 ,

wherein said sensor element is applied to a pressure sensor.

12. The sensor element of claim 1 , wherein the bump portion comprises a surface that is inclined with respect to the fitting portion.