Direct Laser Writing for Micro-Nano Fabrication of Optical and Electronic Structures

Direct Laser Writing for Micro-Nano Fabrication of Optical and Electronic Structures
3:00pm
Room 4475 (Lifts 25-26), 4/F Academic Building, HKUST

Abstract

This thesis explores the pivotal role of micro-nano manufacturing techniques in modern optics and electronics, focusing on the challenges and opportunities they present. We introduces mask-free direct laser writing (DLW) as a novel approach for material patterning, aiming to address limitations of traditional methods and highlighting the advantages of DLW over mask-based techniques. The investigation encompasses the development of a precise material deposition and removal technique for optical and electronic structures fabrication. High-purity metallic deposits of platinum, gold, and silver with ohmic electrical transport were demonstrated. Two application demonstrations—void-free via metallization at aspect ratios up to 5:1 and flexible resistance temperature detectors operating under extreme curvature—validate the platform’s versatility. Complementary DLW-based removal techniques, including deactivation-activation etching of metals and mechanical detachment of atomically thin two-dimensional materials, are developed to enable subtractive patterning within the same optical setup. The deposition capability is further extended to fabricate functional diffractive optical elements, including multifocal Fresnel zone plates and diffraction gratings. Most significantly, simultaneous metal deposition and in-situ 2H-to-1T phase transition at the metal–TMD interface achieves robust ohmic contacts across multiple metal/TMD combinations, confirmed by linear I–V characteristics from 295 K down to 50 K. This work establishes DLW as an accessible and versatile route for two-dimensional material device prototyping and integration.

Speakers / Performers:
Mr. Zeying CHEN
Department of Physics, The Hong Kong University of Science and Technology
Language
English