Implications of Rough Dielectric Surfaces on Charging-Adjusted Actuation of RF-MEMS

Sambit Palit, Purdue University
Xin Xu, Purdue University
Arvind Raman, Purdue University
Muhammad Ashraful Alam, Purdue University

Abstract

Actuation voltage shifts due to dielectric charging is a leading reliability concern in Radio-Frequency Micro-Electro-Mechanical Systems (RF-MEMS) capacitive switches. The inability to correlate dielectric surface roughness to charge accumulation makes predictive design difficult. We apply a sophisticated dielectric charging model on representative surfaces based on Atomic Force Microscopy (AFM) data, and show that there are significant, but predictable actuation voltage shifts due to surface roughness. The results suggest that surface roughness should be considered for accurate lifetime predictions, and simple metal-insulator-metal (MIM) capacitors may serve as a useful test structure for this phenomenon.

Discipline(s)

Electro-Mechanical Systems | Electronic Devices and Semiconductor Manufacturing | Nanotechnology Fabrication