Application of x‐ray lithography for manufacturing a metal‐oxide semiconductor field‐effect transistor tetrode

Using x‐ray lithography the gate level of a MOSFET tetrode was fabricated in a ‘‘mix and match’’ technique. All the other levels were exposed with conventional 400 nm photolithography. As an x‐ray source the synchrotron radiation of the Berlin electron storage ring (BESSY) was used. The employed x‐ray mask is based on a stress compensated Si membrane, which consists of a simultaneously B‐ and Ge‐doped epitaxial layer.