High N-content GaAs1-xNx films (0 ≤ x ≤ 0.055) grown GaAs (001) substrates by MOVPE were investigated using micro-Raman spectroscopy. The nitrogen local vibration mode (N-LVM) which was clearly observed at around 468 - 475 cm-1 is used as a tool to examine the N incorporation. No change in the local environment of N is observed for the high N-containing films with N contents up to x = 0.055. The use of 514.5 nm-line Ar+ laser as the light source gives a linear dependence of the N contents determined by Raman spectroscopy (xRaman) on the N contents determined by the high resolution X-ray diffraction (xXRD) for x XRD ≤ 0.055, providing a realizable calibration method to determine N content in the high N-content GaAs1-xNx films. On the other hand, the use of longer wavelength (632.8 nm-line He-Ne laser) gives a best coincidence for only the lower N contents (x < 0.02). Since, the use of longer wavelength requires the thicker film owing to a thicker optical penetration depth. Thus, in our case, a deviation from the linear behavior for higher N contents, xXRD ≥ 0.02, is not due to the N-related reasons, but this is the results of the additional Raman scattering intensity of GaAs-LO from the substrate.
|Number of pages||3|
|Journal||Physica Status Solidi (C) Current Topics in Solid State Physics|
|Publication status||Published - 2008 Dec 1|
|Event||34th International Symposium on Compound Semiconductors, ISCS-2007 - Kyoto, Japan|
Duration: 2007 Oct 15 → 2007 Oct 18
ASJC Scopus subject areas
- Condensed Matter Physics