Cryogenic microwave performance of silicon nitride and amorphous silicon deposited using low-temperature ICPCVD

TL;DR

This paper investigates the cryogenic microwave performance of silicon nitride and amorphous silicon deposited at low temperature using ICPCVD, focusing on dielectric properties relevant for superconducting detectors.

Contribution

It presents the first detailed study of cryogenic microwave properties of low-temperature ICPCVD-deposited Si3N4, SiNx, and amorphous silicon for superconducting detector applications.

Findings

Dielectric constant measurements at cryogenic temperatures.

Internal quality factors of the deposited dielectrics.

TLS properties relevant for superconducting resonators.

Abstract

Fabrication of dielectrics at low temperature is required for temperature-sensitive detectors. For superconducting detectors, such as transition edge sensors and kinetic inductance detectors, AlMn is widely studied due to its variable superconducting transition temperature at different baking temperatures. Experimentally only the highest baking temperature determines AlMn transition temperature, so we need to control the wafer temperature during the whole process. In general, the highest process temperature happens during dielectric fabrication. Here, we present the cryogenic microwave performance of Si$_{3}$N$_{4}$, SiN$_{x}$ and $\alpha$-Si using ICPCVD at low temperature of 75 $^{\circ}$C. The dielectric constant, internal quality factor and TLS properties are studied using Al parallel plate resonators.