A NOVEL FABRICATION TECHNIQUE OF T-SHAPED GATES USING AN EGMEA AND PMIPK MULTILAYER RESIST SYSTEM AND A SINGLE-STEP ELECTRON-BEAM EXPOSURE

A novel fabrication process of submicron T-shaped gates using an EGMEA and PMIPK multi-layer resist system and e-beam lithography has been d eveloped. Due to the different sensitivities of the EGMEA and PMIPK re sists, narrow/wide/narrow resist opening was obtained. The status of t he electron scattering and the incident primary electron beams statist ically construct the absorbed energy density distribution contours. Th e absorbed energy density distribution contours in association with th e sensitivity feature of the resists and the appropriate development c onditions determine the final resist profile. Only a single exposure s tep and a single development step are required. The simplified fabrica tion process of T-shaped gates significantly reduces not only the proc ess time but also the production costs. The simple submicron T-shaped gate fabrication process studied provides a suitable technique for the mass manufacture of the advanced InP-based and GaAs-based microwave d evices and circuits.