Pulsed Laser Ablation Characteristics of Light-Absorbing Mask Layer Based on Coating Thicknesses under Laser Lift-Off Patterning Process

• Published in: Micromachines (Basel) Vol. 15; no. 6; p. 747
• Main Authors: Hyun, Daehee, Lee, Hee-Lak, Moon, Yoon-Jae, Hwang, Jun-Young, Moon, Seung-Jae
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.06.2024; MDPI
• Subjects: Ablation; Cameras; Coatings; Dielectric films; Electromagnetic absorption; Etching; Fluence; Integrated circuit fabrication; Laser ablation; laser direct patterning; Lasers; lift-off; Oxide coatings; Parameters; Patterning; Photolithography; Photovoltaic cells; Pulsed lasers; Ratios; Solar cells; Substrates; Thickness; Thin films; transparent oxide film; South Korea; United States > US; lift-off; laser ablation; laser direct patterning; transparent oxide film
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi15060747

Thin transparent oxide layers are typically patterned for use in electronic products including semiconductors, displays, and solar cells for applications such as transparent electrodes, insulating films, and encapsulation films. Conventional patterning methods have traditionally been used in photolithography and lift-off processes. Photolithography employs the wet development process, which has disadvantages such as potential undercut effects, swelling, chemical contamination, and high process costs. On the other hand, laser ablation, which has the advantages of high accuracy, high speed, a noncontact nature, and selective processing, can be used to pattern thin films. However, absorption in transparent oxide films is usually low. In this study, experiments were conducted to determine the ablation characteristics of mask layers. The factors affecting ablation, including beam radii, fluences, overlap ratios, and coating thicknesses, were examined; and the parameters characteristic of residue-free ablation, namely the ablation threshold, minimum fluence, and minimum ablation linewidth, were also examined. The experimental results revealed that the beam radius was an important parameter in determining the resolutions of transparent films and substrates.