X-ray lithography for monolithic millimeter wave integrated circuits

X-ray lithography with its high lateral and topographic resolution may be advantageously applied to the fabrication of monolithic millimeter wave integrated circuits on high resistivity silicon. In order to verify this the effects of X-ray exposure on high resistivity silicon were investigated and the fabrication of coplanar Schottky diodes for 90 GHz receiver chips having 0.6 μm anode fingers is demonstrated. To make use of the topographic resolution capability experiments with X-ray resists more than 5 μm thick are reported.