Abstract
Thin films of GaN with the V/III≈10 ratio were grown by low-pressure metal organic vapour phase epitaxy (LP-MOVPE) using N2 and Dimethylhydrazine (DMHy) as a carrier gas and nitrogen precursor, respectively. For the growth temperatures in the range from 550 to 690 {ring operator}C the GaN layers exhibited good surface morphology. In the temperature range from approximately 550 to 610 {ring operator}C, the growth rate increases with increasing temperature, characteristic of the process limited by surface kinetics with the activation energy of approximately 36 kcal/mol. For the temperatures between 620 and 690 {ring operator}C, the growth rate was nearly independent of temperature, which is indicative of a mass transport limited growth. The activation energy was about 4.6 kcal/mol. Micro Raman spectroscopy revealed a significant relaxation of the selection rules for the scattering by the optical phonons in the films grown at lower temperatures. Variation of the intensity ratio for E2H and E1 phonon modes has been attributed to the changes in the structural quality of the films grown at different temperatures.
Original language | English (US) |
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Pages (from-to) | 476-482 |
Number of pages | 7 |
Journal | Superlattices and Microstructures |
Volume | 40 |
Issue number | 4-6 SPEC. ISS. |
DOIs | |
State | Published - Oct 2006 |
All Science Journal Classification (ASJC) codes
- General Materials Science
- Condensed Matter Physics
- Electrical and Electronic Engineering
Keywords
- DMHy
- GaN
- LP-MOVPE
- Micro-Raman spectroscopy