MBE-growth, characterization and properties of InN and InGaN

Abstract

Recent developments on RF‐MBE growth of InN and InGaN and their structural and property characterizations are reviewed. For successful growth of high quality InN, (1) nitridation of the sapphire substrates, (2) two‐step growth, (3) precise control of V/III ratio and (4) selection of optimum growth temperature are found to be essential. Characterization using XRD, TEM, EXAFS and Raman scattering have clearly demonstrated that InN films have ideal hexagonal wurtzite structure. It is also found that the film has N‐polarity. Studies on optimum growth condition dependence on substrate polarity using C and Si face SiC substrates and Ga and N face free‐standing GaN substrates are also demonstrated. The result explains why high‐quality InN grown by RF‐MBE has N‐polarity. PL and CL studies on these well‐characterized high‐quality InN have shown luminescence peaks at approximately 0.75 eV at 77K. These values, however, change slightly depending on measurement temperatures and probably on the residual carrier concentrations. InGaN with full compositional range are also successfully grown on sapphire substrates and band gap energies of these alloys are also studied using PL and CL. Based on these results, true band gap energies of InN are discussed. This paper also includes latest study on single crystalline InN growth on Si (111) substrates. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Growth of high‐quality hexagonal InN on 3C‐SiC (001) by molecular beam epitaxy

“…This crystal orientation reflects anisotropy between [110] and [1-10] of 3C-SiC because the crystal structure of 3C-SiC is zincblende and the 3C-SiC substrates we used are composed of single domain [2]. Sapphire substrates are widely used for the growth of InN, and nitridation prior to growth is essential to obtaining InN which has 6-fold symmetry [3]. On the contrary, nitridation is not needed for the h-InN growth on 3C-SiC substrates.…”

Hydrogen in InN: A ubiquitous phenomenon in molecular beam epitaxy grown material

“…The films with ͑0001͒ orientations were grown on sapphire substrate at three growth laboratories: using GaN buffer layers ͑Cor-nell University͒, 11 GaN templates ͑National Sun Yat-Sen University͒, 12 or low-temperature ͑LT͒ InN buffer layers ͑Ritsumeikan University͒. 13 Details on the samples are given in Table I.…”

Universality of electron accumulation at wurtzite c- and a-plane and zinc-blende InN surfaces

“…9 Details of the various growth methods are reported elsewhere. [9][10][11][12] The x-ray photoemission spectroscopy ͑XPS͒ measurements were performed at room temperature using a Scienta ESCA300 spectrometer at the National Centre for Electron Spectroscopy and Surface Analysis, Daresbury Laboratory, UK. Details of the spectrometer are reported elsewhere.…”