Silicon Nitride Stress Optimization for S-RUM Device Fabrication

Abstract

In this work, we optimized the stress in plasma-deposited SiNx films in order to fabricate tubes with lower diameter for the purpose of device, such as inductors, fabrication. We reached compressive stress as great as -1357 MPa, and tensile stress as great as 664 MPa. We also fabricated rolledup SiNx tubes, which reached inner diameter of 6 μm with membrane thickness around 35 nm. Inductors based on the optimized SiNx recipe have also been fabricated, with an inner diameter of ~90 μm. These results can be used to fabricate devices such as inductors. To better improve the result, changing the deposition temperature is also known to have an impact on the stress. The deposition pressure can also be increased further to see if that brings a change to the stress.