We present a fabrication method for sub-micron lens-coupled lumped element kinetic inductance detectors (LEKIDs) for broadband sub-millimeter (sub-mm) and THz radiation detection. The LEKIDs are fabricated from very thin (12 nm) and narrow (200 nm) aluminum lines to match the impedance of the LEKID to the substrate impedance. The fabrication process is based on a combination of maskless laserwriter lithography and electron beam lithography, providing low (few microns) and high resolution (down to 200 nm) over large areas in a single process. Preliminary optical characterization shows that the fabricated LEKIDs are sensitive to 1.5 THz radiation.

This work was supported as part of a collaborative project, SPACEKIDS, funded via Grant No. 313320 provided by the European Commission under Theme SPA.2012.2.2-01 of Framework Programme 7. D. G. acknowledges RYC-2012-09864 and MAD2D-CM Program (S2013/MIT-3007) for the financial support. A. G., P. P, and J.M-P acknowledge the support from projects AYA2010-21697-C05-01, FIS2012-39262-C06-01, and ESP2013-47809-C3-1-R.

Peer reviewed