Cryogenic Mimim and Simis Microwave Detectors

Microwave detectors of the Metal-Insulator-Metal-Insulator-Metal (MIMIM) structure and the Superconductor-Insulator-Metal-Insulator-Superconductor (SIMIS) structure have been designed, fabricated and investigated. The difference of such samples was in external electrodes, MIMIM uses copper external electrodes, while SIMIS uses aluminum. Identical in dimensions MIMIM and SIMIS samples have been fabricated and experimentally studied in the temperature range of 0.1–2.7 K. Voltage and current response were measured at 300 GHz external irradiation using Backward Wave Oscillator (BWO). According to our estimates, the MIMIM current responsivity is 1.1·103 A/W in the case of a photon response and 4·104 A/W in the case of a bolometric response. The estimated noise equivalent power is in the range 2.5·10 18 W/ √ Hz to 1.2·10−19 W/√Hz.