The optimization of III-nitride submicron technology based on e-beam lithography is described. On AlGaN alloys, procedures must be completely different than on Si, due to the poor electrical conductivity and low chemical reactivity of these materials. To overcome these problems, several metal/resist multilayers have been studied, both theoretically and experimentally, the most successful being the resist/metal/serniconductor and the resist/metal/resist/semiconductor schemes. The applicability of the, optimized procedure was demonstrated in the fabrication of some AlGaN-based devices: surface acoustic wave filters, metal-semiconductor-metal photodiodes, and high electron mobility transistors. All these submicron devices showed a clear improvement of their performance, as expected from size shrinkage.