Vengerovsky Niv, Masters Student

Under the supervision of Prof. Yosi Shacham 

Title: Femtosecond Laser Processing of Ceria-based Micro Actuators

Abstract: This work aims to develop a new process step, much improved than current lithography-based processes, of piezo material based micro-electro-mechanical systems (MEMS) sensors and actuators.

Electroactive actuators based on piezoelectric ceramics became one of the leading MEMS actuator technologies. In the following work precise patterning of electro-active ceramic Ce_0.95Gd_0.05O_1.975 (CGO5) 1.7 µm-thick films by femtosecond laser was demonstrated. Laser patterning was used to fabricate double-clamped beam actuators made of CGO5 sandwiched between two metal contacts

CGO electrostrictive ceramics is lead-free and non-toxic, compatible with Si-microfabrication and exhibits large electrostrictive effect at low frequencies

These qualities make CGO to be a promising electroactive material for MEMS applications. Conventional lithography of metal/CGO/metal on glass or polymers involves also many steps and may cause metal shorts and process compatibility issues affecting the overall yield and reliability

To prevent a short-circuiting between top and bottom contacts due to metal ablation, a margin between the top contact edges and the CGO layer edges was defined prior to laser cutting The resulting devices showed high electrical and mechanical stability, therefore demonstrating feasibility of the fabrication process for such structures

The processes presented in this work provide a technological framework for CGO integration as a promising material in electro-active ceramic-based MEMS-devices

This work was published in Microelectronic Engineering on Sep 2019

Mishuk, E., Shklovsky, J., Berg, Y., Vengerovsky, N., Paul, T., Kotler, Z., ... & Lubomirsky, (2019).

Femtosecond laser processing of ceria-based micro actuators. Microelectronic Engineering, 217, 2019, 111126.‏ https://doi.org/10.1016/j.mee.2019.111126.