Lithography and Etching-Free Microfabrication of Silicon Carbide on Insulator Using Direct UV Laser Ablation

Nguyen, T.K., Phan, H.P., Dowling, K.M., Yalamarthy, A.S., Dinh, T., Balakrishnan, V., Liu, T.Y., Chapin, C.A., Truong, Q.D., Dau, V.T., Goodson, K.E., Senesky, D.G., Dao, D.V., Nguyen, N.T., 2020, "Lithography and Etching-Free Microfabrication of Silicon Carbide on Insulator Using Direct UV Laser Ablation," Advanced Engineering Materials, Vol. 22, 1901173.

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Silicon carbide (SiC)-based microsystems are promising alternatives for silicon-based counterparts in a wide range of applications aiming at conditions of high temperature, high corrosion, and extreme vibration/shock. However, its high resistance to chemical substances makes the fabrication of SiC particularly challenging and less cost-effective. To date, most SiC micromachining processes require time-consuming and high-cost SiC dry-etching steps followed by metal wet etching, which slows down the prototyping and characterization process of SiC devices. This work presents a lithography and etching-free microfabrication for 3C-SiC on insulator-based microelectromechanical systems (MEMS) devices. In particular, a direct laser ablation technique to replace the conventional lithography and etching processes to form functional SiC devices from 3C-SiC-on-glass wafers is used. Utilizing a single line-cutting mode, both metal contact shapes and SiC microstructures can be patterned simultaneously with a remarkably fast speed of over 20 cm s(-1). As a proof of concept, several SiC microdevices, including temperature sensors, strain sensors, and microheaters, are demonstrated, showing the potential of the proposed technique for rapid and reliable prototyping of SiC-based MEMS.

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