GaAs JFETS Intended for Deep Cryogenic VLWIR Readout Electronics

GaAs junction field-effect transistors (JFETs) are promising for deep cryogenic (<10K) readout electronics applications. This paper presents the structure and fabrication of GaAs JFETs and their performance at 4 K. It is shown that these JFETs operate normally at 4 K, with no anomalous behavior such as kinks or hysteresis. The noise voltage follows a 1/√f dependence and is approximately 1 μV/√Hz at 1 Hz for a ring JFET that is 1250 μm in circumference and 5 μm long. The gate leakage current reaches 1 pA at a gate voltage of -6 V