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Next: 5.4.2 Technology B: Pseudomorphic high-power Up: 5.4 Technologies Under Investigation Previous: 5.4 Technologies Under Investigation

5.4.1 Technology A: Pseudomorphic HEMT on GaAs

Technology A is based on a self-aligned optical wafer stepper lithography with phase shift masks, where the subsequent use of SiN sidewall spacers allows to reduce the gate length to $ {\it l}_{\mathrm{g}}$= 120 nm. In an iterative process using dry etching the gate is defined. Typical gate lengths are $ {\it l}_{\mathrm{g}}$= 120 nm-500 nm and intended for large scale production using WSi gate metal. It is available on 4 and 6 inch GaAs wafers. Several variations are derived from this technology.