Tailoring the High-Q LC Filter Arrays for Readout of Kilo-Pixel TES Arrays in the SPICA-SAFARI Instrument

Following earlier presentations of arrays of high quality factor (Q > 10.000) superconducting resonators in the MHz regime, we report on improvement of the packing density of resonance frequencies to 160 in the 1–3 MHz band. Spread in the spacing of resonances is found to be limited to 1 kHz (1 - σ ) with the present fabrication procedure. The present packing density of frequencies and chip area approaches the requirements for the SAFARI instrument on the SPICA mission (in preparation). The a-Si:H dielectric layer in the planar S-I-S capacitors shows a presently unexplained apparent negative effective series resistance, depending on operating temperature and applied testing voltage.