Real-Time Synchrotron X-ray Studies of Low- and High-temperature Nitridation of c-plane Sapphire
The plasma nitridation kinetics of c-plane sapphire at both low (200-300 {sup o}C) and high (750 {sup o}C) substrate temperatures was examined using grazing-incidence real-time x-ray diffraction, in situ x-ray reflection and in situ reflection high-energy electron diffraction (RHEED). These monitored the evolution of the nitride thickness, strain, and surface structure during nitridation. The evolution of the AlN(101{bar 0}) peak showed that the heteroepitaxial strain in the first layer of nitride is already significantly relaxed relative to the substrate. Subsequent layers grow with increasing relaxation. In both the high- and low-temperature nitridation cases, the results suggest that the early stage nitridation is governed by a complex nucleation and growth process. Nitridation at both temperatures apparently proceeds in a two-dimensional growth mode with the initial nucleating islands consisting of several monolayers which grow laterally. At low temperature the growth slows or even stops after impingement of the nucleating islands covering the surface, possibly due to low diffusivities through the existing layer. Initial formation and growth rates of nucleating islands at high temperatures are comparable to those at low temperatures, but subsequent growth into the substrate is significantly enhanced over the low temperature case, consistent with activation energies of 0.1-0.25 eV.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 930605
- Report Number(s):
- BNL-80911-2008-JA; TRN: US0901417
- Journal Information:
- Physical Review B: Condensed Matter and Materials Physics, Vol. 74; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
Similar Records
Aluminum Nitride Micro-Channels Grown via Metal Organic Vapor Phase Epitaxy for MEMs Applications
Effect of nitridation of the sapphire (0001) substrate on the GaN growth
Related Subjects
ACTIVATION ENERGY
ELECTRON DIFFRACTION
GRAZING INCIDENCE TOMOGRAPHY
IMPINGEMENT
KINETICS
NITRIDATION
NITRIDES
NUCLEATION
PLASMA
REFLECTION
RELAXATION
SAPPHIRE
STRAINS
SUBSTRATES
SYNCHROTRON RADIATION
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0400-1000 K
THICKNESS
X-RAY DIFFRACTION
national synchrotron light source