Method for implementing an efficient and economical cathode process

The present invention provides a method of fabricating a cathode requiring relatively few and somewhat simple steps. In one embodiment, a novel etchant gas chemistry dispenses with needing a second passivation layer. In one embodiment, a direct via is formed without a separate mask. In one embodiment, access and isolation features of a metallic gate are patterned in the same patterning operation as an associated passivation layer, dispensing with a need for separate patterning of each. In one embodiment, etching is effectuated with high selectivity for nitrides of silicon. In one embodiment, the requirement for at least one passivation layer deposition, a direct via masking step, and separate patterning steps for the passivation layer and metallic gate are eliminated. This effectively eliminates or substantially reduces associated costs, concomitantly reducing process completion time. Advantageously, this increases efficiency and productivity, correspondingly reducing fabrication costs and unit costs of finished devices.