TEM studies of laterally overgrown GaN layers grown on non-polarsubstrates
Transmission electron microscopy (TEM) was used to study pendeo-epitaxial GaN layers grown on polar and non-polar 4H SiC substrates. The structural quality of the overgrown layers was evaluated using a number of TEM methods. Growth of pendeo-epitaxial layers on polar substrates leads to better structural quality of the overgrown areas, however edge-on dislocations are found at the meeting fronts of two wings. Some misorientation between the 'seed' area and wing area was detected by Convergent Beam Electron Diffraction. Growth of pendeo-epitaxial layers on non-polar substrates is more difficult. Two wings on the opposite site of the seed area grow in two different polar directions with different growth rates. Most dislocations in a wing grown with Ga polarity are 10 times wider than wings grown with N-polarity making coalescence of these layers difficult. Most dislocations in a wing grown with Ga polarity bend in a direction parallel to the substrate, but some of them also propagate to the sample surface. Stacking faults formed on the c-plane and prismatic plane occasionally were found. Some misorientation between the wings and seed was detected using Large Angle Convergent Beam Diffraction.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE; AFOSR ISSA 06NE001
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 920343
- Report Number(s):
- LBNL-60794; R&D Project: M70022; BnR: 400403109; TRN: US200818%%1145
- Resource Relation:
- Conference: Photonic West SPIE-The International Society forOptical Engineering, San Jose, CA, 1/22-1-16/06
- Country of Publication:
- United States
- Language:
- English
Similar Records
Structural properties of laterally overgrown GaN
Transmission Electron Microscopy Study of Nonpolar a-Plane GaNGrown by Pendeo-Epitaxy on (112_0) 4H-SiC