Optical emission spectrometry of plasma in low-damage sub-100 nm tungsten gate reactive ion etching process for compound semiconductor transistors

Li, X. , Zhou, H., Wilkinson, C. D.W. and Thayne, I. G. (2006) Optical emission spectrometry of plasma in low-damage sub-100 nm tungsten gate reactive ion etching process for compound semiconductor transistors. Japanese Journal of Applied Physics, 45(Pt.1), pp. 8364-8369. (doi: 10.1143/JJAP.45.8364)

Abstract

In this study, we investigate in situ optical emission spectra from plasma in the reactive ion etching (RIE) of tungsten, a suitable candidate for gate metallization in compound-semiconductor-based high-mobility channel devices. This results in a detailed understanding of the effects of etching parameters vital to reducing etch induced damage and improving etching performance. A SF6 based chemistry was used with other functional gases, such as N2, O2, and CHF3. Van de Pauw (VdP) structures on GaAs based high electron mobility transistor (HEMT) layer structures were used for evaluating plasma-induced damage in the RIE process. The optimised process results in a maximum increase of 15% in the sheet resistance of the semiconductor material. Etched tungsten line widths down to 25 nm with well controlled profile were obtained by adjusting the etching conditions based on the understanding of the etching mechanism.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Zhou, Dr Haiping and Thayne, Prof Iain and Wilkinson, Professor Christopher and Li, Dr Xu
• Authors: Li, X., Zhou, H., Wilkinson, C. D.W., and Thayne, I. G.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Japanese Journal of Applied Physics
• Publisher: IOP Publishing
• ISSN: 0021-4922
• ISSN (Online): 1347-4065