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

Abstract A high-density N 2 plasma was generated after mode jump by a helical antenna surrounded by magnetic coils. In the wavelength region of 600–800 nm, the emission lines from the N 2 first positive system and that from N atoms (3p→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 before and after mode jump. N 1s peak intensities from the surface layer nitrided in the N 2 plasma after mode jump measured by X-ray photoelectron spectroscopy were 2–5 times larger than those nitrided before mode jump, which indicates the enhancement of the nitridation. From the spectroscopic ellipsometry, the thickness of nitrided layer was 3–11 nm.