Laser-induced interaction of ammonia with GaAs(100). I. Dissociation and nitridation

Abstract

UV laser irradiation of ammonia adsorbed on GaAs(100) leads to molecular desorption and dissociation. A nitride passivation layer can be formed on the GaAs surface at 100 K by simultaneous exposure to ammonia and uv photons in a UHV environment. The nitride layer consists of a mixture of Ga and As nitrides. While the dominating GaN surface species is thermally stable, AsN desorbs below 800 K. Surface NH2 is identified as an intermediate. The implication of this study for selective area passivation and GaN growth is discussed.

LPCVD of InN on GaAs(110) Using HN3 and TMIn: Comparison with Si(100) Results

“…After a deposition time of 1.5 h, Ga2p.312 XPS intensity decreased by -60% and the peak could be deconvoluted into two components at 1116.6 and 1117.1 eV due to Ga atoms in substrate and those bonded to N atoms, respectively. The 1117.1 eV peak is about 0.7 eV lower than the value of 1117.8 observed for GaN [13,14], likely because of the fact that the N atom is bonded to an In atom simultaneously. Similar changes were noted in the As2 3t2 XP spectrum.…”

“…This broad peak can be further deconvoluted into two components at 1323sand 1324. 6 Binding Energy (eV) Binding Energy (eV) Binding Energy (eV) Binding Energy (eV) The Ga2p-3/2, XPS peak became broader, shifted to 1116.9 and could be deconvoluted into two components at 1116.6 and 1117.1 eV due to substrate and nitride Ga atoms, respectively [13,14]. Meanwhile, the In3d.5/2, and NIS photoelectrons presented peaks at 4.44.6 and 39'.9 eV, respectively.…”

Nitridation of GaAs Surface by Low Energy Ion Implantation with In Situ Control of Chemical Composition

“…(DeLouise, 1992) and is less by 0.3 eV than the value given in Ref. (Zhu et al, 1992;Li et al, 2001). High total energy resolution of the beamline used and the endstation enabled revealing some asymmetry of N1s photoemission line related to additional contribution at higher binding energy where the line of GaAsN was expected.…”

Nitridation of GaAs (001)-2×4 Surface Studied by Auger-Electron Spectroscopy

“…In addition, the As-signal during nitridation also exhibits a shoulder at the low-KE side of the spectra, this shoulder becoming more pronounced with decrease in the nitridation temperature. On the basis of the previous XPS results the above shoulder has been attributed to the surface AsN species, and the disappearance of this peak at higher temperatures is caused by desorption of the AsN species from the surface [2,3]. The Noriginated spectra during nitridation also exhibit a shoulder at the low-energy side of the spectra separated by ~ 2.0 eV from the main N-KLL peak (Fig.…”

“…However, a deeper understanding of the mechanisms governing initial stages of nitridation and subsequent nitride growth is vital for improvement of device performance. The formation of Ga-N and As-N bonds on the GaAs (001) surface during nitridation has been verified by X-ray photoelectron spectroscopy (XPS) [2,3], the results showing chemical shifts of the core levels of Ga, As and N caused by the nitridation process, with the formation of a disordered Ga-As-N phase in the subsurface region of the substrate. However, all XPS experiments have been carried out after nitridation by either transferring the nitrided sample from the "nitridation" chamber to the "XPS" chamber or by switching between nitridation and measurement cycles in the same chamber.…”