Stress Induced Microstructure Evolution of AlN: Er Film at Different Annealing Temperature

The microstructure evolution of AlN: Er during thermal treatment was mainly characterized by weak beam diffraction-contrast imaging and high resolution phase-contrast imaging of the transmission electron microscopy (TEM), which was also supported by X-ray diffraction (XRD) and Raman spectroscopy. Three regions could be observed in the TEM for the implanted samples. The region I is about 30 nm in depth below the surface, the region II is about 50 nm in depth under the region I and is the worst damaged area, and the region III is the area below the reigion II. At relatively low annealing temperature, such as 1025 degrees C, the region I disappears. However, this area can be observed again after annealing at 1200 degrees C. Based on the results of XRD, Raman and TEM, the interesting experiment phenomenon are explained on the view of damage recovery and stress releasing. There is a large stress in the region II due to the large radius difference between Er ions and Ga ions. In the annealing process at 1025 degrees C, the region I is affected by the stress from region II, the lattice distortion in region I is produced. Therefore, the region I is observed as region II under TEM observation. In the annealing process at 1200 degrees C, the stress in the region I is released from the surface, the lattice distortion is removed and the region I is observed again under TEM