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.