Characteristics of GaAs complementary heterojunction FETs and C-HFET-based amplifiers exposed to high proton fluences

Test results with GaAs CHFETs and CHFET-based monolithic preamplifiers irradiated with up to 5 × 1014p/cm2 are reported. The DC and noise characteristics of all transistors were measured before and after irradiation. Additionally, measurements on the DC and AC characteristics of monolithic preamplifiers in CHFET-technology were performed. the irradiation with 5 × 1014p/cm2 all devices are fully functional and show normal behaviour. For a pixel detector with a capacitance of 150 fF connected to an amplifier with an input transistor of 25 μm gate width operating with a drain current density of 0.25 mA/mm, the extrapolated ENC increases from 100 to 120 electrons for a peaking time of 25 ns. In this region of operation, the gate current is still in the order of nA. asurements of the FETs were performed in the low-power consumption region with drain current densities less than 2 mA/mm.