PT Journal
AU Hajenius, M
   Baselmans, JJA
   Gao, JR
   Klapwijk, TM
   de Korte, PAJ
   Voronov, B
   Gol'tsman, G
TI Low noise NbN superconducting hot electron bolometer mixers at 1.9 and 2.5 THz
SO Supercond. Sci. Technol.
JI Supercond. Sci. Technol.
PY 2004
BP S224-S228
VL 17
IS 5
DI 10.1088/0953-2048/17/5/026
DE NbN HEB mixers
AB NbN phonon-cooled hot electron bolometer mixers (HEBs) have been realized with negligible contact resistance between the bolometer itself and the contact structure. Using a combination of in situ cleaning of the NbN film and the use of an additional superconducting interlayer of a 10 nm NbTiN layer between the Au of the contact structure and the NbN film superior noise temperatures have been obtained as low as 950 K at 2.5 THz and 750 K at 1.9 THz. Here we address in detail the DC characterization of these devices, the interface transparencies between the bolometers and the contacts and the consequences of these factors on the mixer performance.
ER