A novel fabrication technique of T-shaped gates using an EGMEA and PMIPK multi-layer 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 developed. Due to the different sensitivities of the EGMEA and PMIPK resists, narrow/wide/narrow resist opening was obtained. The status of the electron scattering and the incident primary electron beams statistically construct the absorbed energy density distribution contours. The absorbed energy density distribution contours in association with the sensitivity feature of the resists and the appropriate development conditions determine the final resist profile. Only a single exposure step and a single development step are required. The simplified fabrication process of T-shaped gates significantly reduces not only the process 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 devices and circuits.