Fabrication of silicon field-emission arrays using masks of amorphous hydrogenated carbon films

A fabrication process of silicon field-emission arrays is reported, in which thin films of amorphous hydrogenated carbon (a-C:H) are employed as masks in a two-step plasma-etching process, using pure SF₆ and a mixture of SF₆ and O₂. In comparison with processes that involve SiO₂ masks, the use of a-C:H improved the selectivity of the plasma etching, particularly in the case of pure SF₆. An estimation of Utsumi's figure of merit showed that a significant enhancement in electric field can be achieved, as a result of the sharp tips fabricated through this process.