Optical control of group-III and N flux intensities in plasma-assisted MBE with RF capacitively-coupled magnetron nitrogen activator

A new technique of in situ optical control of III/N flux ratio in plasma-assisted MBE of group-III nitrides (GaN, InN) have been proposed. It is based on the observation of group-III and nitrogen related lines in the optical emission spectra of plasma in the growth chamber of MBE set-up equipped with the rf capacitively-coupled magnetron N 2 -activator operated in a new extended mode. Structural and optical studies have confirmed the importance of precise keeping the III/N ratio in a slightly III-rich regime during the growth to be optimal. The best GaN films without any buffer layers, grown using such flux ratio control, demonstrate a FWHM of GaN (0002) peak of 609 and 54 arcsec in θ and θ - 2θ scans, respectively. Their PL spectra are dominated by the exciton lines BX A at 3.475 eV and FX A at 3.481 eV. In Raman scattering spectra best InN epi-layers grown on sapphire demonstrate a higher intensity of E 2 peak in comparison with the A 1 (LO) peak.