Improved Vertical p-Type Radio Frequency Metal-Base Transistors

This letter reports radio frequency (RF) transistors using a high-resistivity p-type float zone silicon wafer. A high-density uniform organic semiconducting single layer is deposited using thermal evaporation technique, and RF transistors with a base layer of about 60 nm are fabricated. We report on a transistor exhibiting a cutoff frequency (f_T) of 630 kHz. In addition to the cutoff frequency, other important figures of merit for the RF transistor are also presented, including the common-emitter current gain and on/off ratio.