Broad-Pulsed Ga Ion-Beam-Assisted Etching of Si with Cl 2

• Published in: Japanese Journal of Applied Physics 1993-12, Vol.32 (12S), p.6168
• Main Authors: Satoshi Haraichi, Satoshi Haraichi, Masanori Komuro, Masanori Komuro
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.32.6168

The characteristics of ion-beam-assisted etching (IBAE) of Si with Cl 2 have been investigated using a broad-pulsed Ga ion beam, with several parameters such as Cl 2 gas flux, ion beam dwell time, sample temperature, and beam diameter. A simple adsorption model where the density of the adsorbed Cl 2 molecules mainly rules the etching yield, can explain the trend of the process in a short dwell-time region of less than 1 ms, and etching parameters are determined. However in a longer dwell-time region of more than 10 ms, the experiment showed several times higher etching yield than the prediction using the simple model with a 2.2-µm-diam beam. The etching model with consideration of Cl 2 surface diffusion can explain this difference in etching yield and shows good agreement with the experiment throughout the entire region of dwell time. A diffusion coefficient of 8.0×10 -6 cm 2 /s at room temperature was obtained by fitting theoretical curves in the experiment.