Optimizing the dielectric for superconducting THz detectors

On-chip superconducting electronics are revolutionizing the fabrication of astronomical radiation detectors and spectrometers both in the optical, near-infrared and far-infrared. It is also the key technology for transmon qubits, which are the most promising building blocks for Quantum computers. They all use the fact that, in theory, superconductors have extremely low loss at very low temperatures.

However, current devices are limited by the losses in the dielectric surrounding the waveguides, resulting in losses that are 10-100x larger than theoretically possible. We have identified that PECVD SiC is a very promising dielectric that can outperform the state-of-the-art. Further improvements should be possible by optimizing the deposition parameters, and thereby the composition of the dielectric. This may also help us in understanding the physical origin of the losses.

This project is a collaboration between Akira Endo (THz-group) and Sten Vollebregt (ECTM). Supervision will also be done by the PhD student Bruno Buijtendorp

Assignment

• Optimize SiC by changing CVD parameters
• Room temperature measurements using ellipsometry and wafer-bow (stress)
• Cryogenic measurements using lab-on-chip device

This project is a collaboration between the THz group and ECTM.

Contact

Last modified: 2024-02-27