Lateral resolution in laser-patterned thermal processing of GaAs

• Published in: Applied surface science Vol. 125; no. 3; pp. 325 - 331
• Main Author: Sadra, K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.1998; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Impact phenomena (including electron spectra and sputtering); Laser-beam impact phenomena; Materials science; Physics; Surface cleaning, etching, patterning; Surface treatments; Thermal diffusion; Patterning; Gallium arsenides; Inorganic compounds; Laser radiation; Physical radiation effects; Theoretical study; Surface treatments
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/S0169-4332(97)00421-2

Time-dependent two-dimensional calculations are employed to estimate the limits placed, by thermal diffusion, on the lateral resolution of thermally-activated excimer-laser-induced patterned processing of GaAs. Sinusoidal and rectangular fluence profiles are used for holographic or projection exposure. Despite thermal diffusion, holographic exposure can result in feature sizes well into the nanostructure regime, except for low activation energy processes conducted at low peak temperatures. In projection patterning, pattern fidelity is severely affected by thermal diffusion. In this case, reasonably rectangular process profiles can only be obtained for feature sizes as large as several microns, unless hard process thresholds and/or stopping layers are involved.