Patent ID: 8338205

Claim:
A method for fabricating and encapsulating a suspended microstructure onto a substrate at least comprising: depositing a first sacrificial carbon film onto the substrate; partially protecting the first sacrificial carbon film by a photolithographically defined first photoresist; photolithographically patterning the first sacrificial carbon film by using oxygen plasma ashing or nitrogen plasma ashing process; selectively stripping the first photoresist by wet chemical photoresist stripping process; depositing a structural film; photolithographically patterning the structural film with a lithographically defined second photoresist and partially exposing the first sacrificial carbon film; depositing a second sacrificial carbon film; partially protecting the second sacrificial carbon film by a photolithographically defined third photoresist; photolithographically patterning the second sacrificial carbon film by using oxygen plasma ashing or nitrogen plasma ashing process; selectively stripping the third photoresist by wet chemical photoresist stripping process; depositing an encapsulating film covering the second sacrificial carbon film, the structural film and the first sacrificial carbon film; photolithographically patterning the encapsulating film to form a plurality of thru-film sacrificial release holes; selectively removing the first sacrificial carbon film and the second sacrificial carbon film by using a selective gaseous etch process in a reactor chamber so that the structural film is suspended in a cavity above the substrate; and depositing a hole-sealing film so that the thru-film sacrificial release holes are sealed; wherein the first sacrificial carbon film and the second sacrificial carbon film are deposited by: placing the substrate in a reactor chamber; introducing a carbon-containing process gas into the chamber and introducing a layer-enhancing additive gas that enhances thermal properties of the first sacrificial carbon film and the second sacrificial 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.