Preparation process for graphene resonant gas sensor based on doped metal atoms

[0033]Specific implementation steps are as follows:

[0034]Step 1: a SiO2 dielectric layer 2 having a thickness of 100 nm is deposited on a Si substrate 1 by a CVD method, as shown in FIG. 1. Then, a ultrasonic cleaning is performed on the SiO2 dielectric layer 2 by using absolute ethanol and deionized water, where the ultrasonic power is 30 to 45 W, and the cleaning time is 3 to 5 minutes.

[0035]Step 2: a PPA having a thickness of 1000 nm is spin-coated on the surface of the SiO2 dielectric layer 2, where the type of the PPA is poly(phthalaldehyde), the viscosity of the PPA is 5 cp, the rotation speed of a spin-coater is 1000 to 2000 r / min, and the spin-coating time is 30 s. Three rectangular grooves are etched in the PPA by using a direct writing machine having a nano 3D structure, where for the three rectangular grooves, depths of the grooves are all 1000 nm; lengths of grooves on two sides are both 1000 nm, and widths of grooves on two sides are both 1000 nm; a length of a middle gr