Electrical Contacts in SOI MEMS Using Aerosol Jet Printing

In this paper, an additive method to make electrical contacts in SOI MEMS devices with aerosol jet printing is introduced. Small grooves were etched to the frame of MEMS accelerometer in the same step with the active structure release. Aluminum ink was jetted to the trenches in wafer-level to bridge the device layer to the handle wafer with the minimum amount of material. After subsequent annealing, ohmic contacts between p-type device layer and p-type handle silicon were verified by I-V measurements. The via resistance less than 4 Ω per via is measured. The method demonstrated in this paper provides simple and low-cost approach for SOI handle contact where additional packaging of wafer process steps can be avoided.