PT Journal
AU Finkel, M
   Thierschmann, H
   Galatro, L
   Katan, AJ
   Thoen, DJ
   de Visser, PJ
   Spirito, M
   Klapwijk, TM
TI Performance of THz components based on microstrip PECVD SiN[sub:x] technology
SO IEEE Trans. THz Sci. Technol.
JI IEEE Trans. THz Sci. Technol.
PY 2017
BP 765
EP 771
VL 7
IS 6
DI 10.1109/TTHZ.2017.2759507
DE transmission line measurements; power transmission lines; dielectrics; couplers; submillimeter wave circuits; coplanar waveguides; micromechanical devices
AB We present a performance analysis of passive THz components based on Microstrip transmission lines with a 2-μmthin plasma-enhanced chemical vapor deposition grown silicon nitride (PECVD SiNX) dielectric layer. A set of thru-reflect-line calibration structures is used for basic transmission line characterizations. We obtain losses of 9 dB/mm at 300 GHz. Branchline hybrid couplers are realized that exhibit 2.5-dB insertion loss, 1-dB amplitude imbalance, and -26-dB isolation, in agreement with simulations. We use the measured center frequency to determine the dielectric constant of the PECVD SiN x , which yields 5.9. We estimate the wafer-to-wafer variations to be of the order of 1%. Directional couplers are presented which exhibit -12-dB transmission to the coupled port and -26 dB to the isolated port. For transmission lines with 5-μm-thin silicon nitride (SiN x ), we observe losses below 4 dB/mm. The thin SiN x dielectric membrane makes the THz components compatible with scanning probe microscopy cantilevers allowing the application of this technology in on-chip circuits of a THz near-field microscope.
ER