Gate tunneling current in In/sub 0.53/Ga/sub 0.47/As junction field-effect transistors

Data are presented which conclusively eliminate channel current impact ionization as the dominant source of gate leakage current in InGaAs JFETs based on both the temperature and channel current dependence. At the same time, strong evidence is presented which indicates that band-to-band tunneling at the gate-drain interface is the dominant source of gate leakage current. Based on these and previous results, it is concluded that InGaAs JFETs in linear preamplifiers such as optical receivers have an optimum channel doping of approximately 9*10/sup 16/ cm/sup -3/ at a bandwidth of 1 GHz. This value is obtained based on a tradeoff between gain, bandwidth, and noise.<>