MEMS device and method of fabricating the same

1. A method for fabricating the MEMS device, comprising:

depositing a first carbon film onto a substrate;

lithographically patterning the first carbon film to remove a first sacrificial pre-removal portion to expose the substrate, the first sacrificial pre-removal portion corresponding to a first recess portion of a suspended thin film microstructure;

depositing a second carbon film conformally onto the first carbon film, wherein a portion of the second carbon film corresponding to the first recess portion is in direct contact with the substrate at a location corresponding to the first sacrificial pre-removal portion;

lithographically patterning the second carbon film to form an opening so as to expose an anchoring portion of the substrate;

depositing and lithographically patterning the suspended thin film microstructure onto a stack of the first carbon film and the second carbon film; and

removing the first carbon film and the second carbon film.

2. The method according to claim 1 , wherein, before the step of lithographically patterning the second carbon film to form an opening so as to expose an anchoring portion of the substrate, the method further comprises:

lithographically patterning the second carbon film to remove a second sacrificial pre-removal portion to expose the substrate, the second sacrificial pre-removal portion corresponding to a second recess portion of the suspended thin film microstructure;

depositing a third carbon film conformally onto the second carbon film, wherein a portion of the third carbon film corresponding to the second recess portion is in direct contact with the substrate at a location corresponding to the second sacrificial pre-removal portion;

the step of depositing and lithographically patterning the suspended thin film microstructure onto a stack of the first carbon film and the second carbon film comprises:

depositing and lithographically patterning the suspended thin film microstructure onto a stack of the first carbon film, the second carbon film and the third carbon film;

the step of removing the first carbon film and the second carbon film comprises:

removing the first carbon film, the second carbon film, and the third carbon film to form a suspended thin film microstructure with the first recess portion and the second recess portion, wherein a first vertical clearance between a bottom surface of the first recess portion and a top surface of the substrate is smaller than a second vertical clearance between a bottom surface of the second recess portion and the top surface of the substrate.

3. The method according to claim 2 , wherein any of the first carbon film, the second carbon film and the third carbon film is removed by selective etch process gas of oxygen or nitrogen in a reactor chamber containing plasma generated with a plasma source power.

4. The method according to claim 2 , wherein the first carbon film, the second carbon film or the third carbon film is deposited by means of:

placing the substrate in a reactor chamber;

introducing a carbon-containing process gas into the reactor chamber and introducing a layer-enhancing additive gas that enhances thermal properties of the first carbon film, the second carbon film or the third carbon film;

generating a reentrant toroidal RF plasma current in a reentrant path that includes a process zone overlying the substrate by coupling a plasma RF source power to an external portion of the reentrant path; and

coupling RF plasma bias power or bias voltage to the substrate.

5. The method according to claim 4 , wherein the first carbon film, the second carbon film or the third carbon film comprises less than 9 percent of hydrogen.