Abstract

Femtosecond lasers deliver a high peak concentration of optical power while maintaining low average power. With an accompanying optical setup, this power can be focused and used for high-precision fabrication of metallized polymers via ablation, creating conductive structures on a thin film. These lasers can also be harnessed in tandem with hydrofluoric acid and the two-photon absorption principle to selectively etch silicon carbide, a very durable and machining-resistant semiconductor with desirable properties. This thesis presents improvements made to the Laser-Assisted Chemical Etching (LACE) technique and the ablation system. ��, the two- photon absorption coefficient of silicon carbide, is measured and characterized for each wafer using an optical system. The LACE etch rate of silicon carbide is found to be on average a quarter of a micrometer per 120 seconds. A new destructive imaging technique for characterizing high- aspect-ratio through-wafer non-line-of-sight features in silicon carbide is discussed, with the result of an SEM image of a LACE feature that was impossible to achieve previously. The photolithography process necessary to make use of those through-wafer features is explored. A method of leveraging image processing to maintain the focus of the laser close to the machined sample is explained, resulting in the creation of terahertz metal- mesh filters with a near one-hundred-percent success rate. It is recommended that future work explore the use of an installed confocal microscopy as a method of surface-tracking and result characterization.

Degree

College and Department

Ira A. Fulton College of Engineering; Electrical and Computer Engineering

Rights

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