High-performance millimetrewave GaAs Schottky-barrier flip-chip diode

The growth in knowledge attained in astronomy as a result of the study of millimeter and submillimeter radio signals has been made possible by the employment of the Schottky-barrier diode with its extreme sensitivity and its capability for low-noise operation. The standard structure of the Schottky-diode chip involves the use of a sharply pointed whisker. This contact whisker can cause operational difficulties. The considered investigation is concerned with the development of a new millimeterwave Schottky-diode structure which eliminates the whisker completely and allows direct bonding of the anode to the RF choke structure. It is shown that the technology for fabrication and mounting a flip-flop diode is practical. Even initial tests under far from ideal conditions yielded reasonable RF data.