Investigation of the metallization of Gunn diode and process

A practical heat sink fabrication process for low-cost, high-power and millimeter-wave devices was presented. The uniformly doping epitaxial structure(n n+) was grown by molecular beam epitaxy(MBE) on heavily-doped n++ InP substrate. Also a batch-fabrication technique for mesas with gold heat sink was proposed. A technology was developed to form ohmic contacts to indium phosphide Gunn diodes, and the metallization of cathode and anode was fabricated by Ge/Au/Ni/Au evaporation, and was annealed at different temperature. Results show that the best ohmic contact is formed at 450 ℃. The complete fabrication procedure is described to realize the Gunn devices for low-cost millimeter-wave applications. By the way, wet etching could get approximately vertical MESA structure by HCl-based solution.