Deep etching of epitaxial gallium nitride film by multiwavelength excitation process using F2 and KrF excimer lasers

• Published in: Applied physics. A, Materials science & processing Vol. 82; no. 3; pp. 479 - 483
• Main Authors: OBATA, K, SUGIOKA, K, MIDORIKAWA, K, INAMURA, T, TAKAI, H
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01-03-2006; Springer Nature B.V
• Subjects: Ablation; Aluminum oxide; Applied physics; Cross-disciplinary physics: materials science; rheology; Epitaxial growth; Etching; Exact sciences and technology; Excimer lasers; Excimers; Gallium nitrides; Incidence angle; Isotopes; Krypton fluoride lasers; Laser ablation; Lasers; Materials science; Physics; Surface cleaning, etching, patterning; Surface treatments; Thin films; Radiation effects; Scanning electron microscopy; Epitaxial layers; Semiconductor materials; Gallium nitrides; Etching rate; Incidence angle; Excited states; Laser beam etching; Depth
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-005-3409-8

The deep etching of GaN(0001) thin films epitaxially grown on Al2O3(0001) has been investigated by laser ablation using F2 and KrF excimer lasers. The simultaneous irradiation with F2 and KrF excimer lasers markedly improves etching quality compared with single-KrF excimer laser ablation and provides almost the same quality as that in the case of single-F2 laser ablation with a high etching rate. Additionally, the present method achieves the deep etching of a GaN film of more than 5 μm in depth with steep side walls at an angle of 87° by changing the laser incidence angle.