Cold-electron bolometer integrated with a unilateral finline

Paper in proceeding, 2010

The Cold-Electron Bolometer (CEB) is a very sensitive millimetre-wave detector which is easy to integrate with planar circuits. CEB detectors have other important features such as high saturation power and very fast response. We have designed, fabricated and tested CEB detectors integrated across the slot of a unilateral finline on silicon substrate. Bolometers were fabricated using e-beam directwrite trilayer technology. The CEB performance was tested in a He3 sorption cryostat HELIOX-AC-V at a bath temperature of 280 mK. To reduce the background power radiation overheating the optical window in the cryostat was equipped with two low-pass filters with cut-off frequency 33 cm-1 and 100 cm-1 and 2 neutral density filters with 10 db attenuation each. DC IV curves were measured in a current bias mode, optical response was measured by irradiating samples with a microwave signal from IMPATT diode at 110 GHz modulated at 127 Hz. These tests were conducted by coupling power directly into the finline chip. The signal response was measured using a lock-in amplifier. The bolometer dark electrical noise equivalent power is estimated to be about NEP=5·10-16 W/Hz1/2.