TUNNETT Operation Mode in Silicon

Using DC and RF characterization techniques the transition from impact avalanche transit time (IMPATT) to tunnel injection transit time (TUNNETT) operation is investigated by varying the width of the generation zone in p-type lo-hi-lo (p LHL) structures. DC results show, that the doping height of the hi zone is a very crucial parameter, where tolerances become the narrower the smaller the generation zone width gets. The smallest widths realized amount to few ten nanometers. In this range still significant avalanche multiplication is present (M > 1000). S-parameter measurements, on the other hand, reveal a low impedance level which is more typical to in-phase injection TUNNEIT than to IMPATT operation. Preliminary RF results regarding output power and noise performance are 10 dBm (f = 78 GHz) and ¿84 dBc/Hz at 1 MHz offset frequency, respectively.