Epitaxially Grown, Germanium, Junction Field-Effect Transistor for Cryogenic Detectors

An epitaxial grown Germanium - channel Junction Field Effect Transistor (Ge-JFET) is proposed to provide the most efficient, low noise cryogenically cooled detectors operating at 2 - 4¿K. Precisioned engineered lattice and doping epitaxial growth will eliminate material defects to allow the Germanium superior low temperature mobilities to be utilized in the most efficient cryogenic temperature transistors technology available (JFETs). The low resistance Al/Pd contacts on the engineered p-n-p structure will result in Ge-channel JFET detectors with very low noise at audio frequencies (lOHz), high input impedance and low power dissipation. TLC expect to demonstrate Ge-JFETs with less than l0nV of noise at lOOHz and 4¿K. This proposal summarizes how TLC will develop and demonstrate the material, fabrication and performance advantages of epitaxial grown Ge-JFETs for cryogenically cooled detector for