Characterization of the surface layer of GaAs nitrided by high-density plasma

A high-density N-2 plasma was generated after mode jump by a helical antenn a surrounded by magnetic coils. In the wavelength region of 600-800 nm. the emission lints from the N-2 first positive system and that from N atoms (3 p --> 3s) were also observed, in addition to the emission lines from the N- 2 second positive and N-2(+) first negative systems in the ultraviolet and violet regions. At the mode jump, the emission peak intensity from N atoms especially increased. Nitridation of GaAs was performed in the N-2 plasma b efore and after mode jump. N 1s peak intensities from the surface layer nit rided in the N-2 plasma after mode jump measured by X-ray photoelectron spe ctroscopy were 2-5 times larger than those nitrided before mode jump. which indicates the enhancement of the nitridation. From the spectroscopic ellip sometry, the thickness of nitrided layer was 3-11nm. (C) 2001 Elsevier Scie nce B.V. All rights reserved.