2. Technological processes for HEMT devices

To implement HEMT transistor technology, two lithography processes are used to carry out the various stages: optical lithography, which can produce grids up to around 1 µm in length, and electronic lithography, which is a state-of-the-art tool for designing submicrometer grids. The latter technique enables patterns to be written with a resolution down to the tens of nanometers. We use a set of masks comprising several writing levels, corresponding to the different stages in the manufacture of HEMTs. Figure 9 shows a HEMT component at the end of the