Photochemical etching of silicon by two photon absorption

✍ Scribed by Ouyang, H. ;Deng, Y. ;Knox, W. H. ;Fauchet, P. M.

• Book ID: 105364181
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 449 KB
• Volume: 204
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200674303

✦ Synopsis

Abstract

Photochemical etching of silicon assisted by two‐photon absorption (TPA) in the presence of hydrofluoric acid (HF) is demonstrated using a below‐bandgap femtosecond laser source. We investigate the morphology of the etched silicon as a function of the laser power, exposure time, as well as the substrate doping level. Self‐organized periodic silicon trenches with ∼150 nm spacing were observed at the etch front as the initial stage of the TPA photochemical etching process. Since the etching front can be precisely controlled by the focal point, this technique can be used for writing silicon microfluidic systems and for 3D micromachining. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)