Influence of Mg and In on defect formation in GaN; bulk and MOCVD grown samples
Transmission electron microscopy studies were applied to study GaN crystals doped with Mg. Both: bulk GaN:Mg crystals grown by a high pressure and high temperature process and those grown by metal-organic chemical-vapor deposition (MOCVD) have been studied. Structural dependence on growth polarity was observed in the bulk crystals. Spontaneous ordering (formation of polytypoids) was observed for growth in the N to Ga polar direction (N polarity). On the opposite site of the crystal (growth in the Ga to N polar direction) Mg-rich pyramidal defects with base on the basal planes and with walls inclined about 45O to these planes, empty inside (pinholes) were observed. A high concentration of these pyramidal defects was also observed in the MOCVD grown crystals. For samples grown with Mg delta doping planar defects were also observed especially at the early stages of growth followed by formation of pyramidal defects. TEM and x-ray studies of InxGa{sub 1{minus}x}N crystals for the range of 28-45% nominal In concentration shows formation of two sub-layers: strained and relaxed, with a much lower In concentration in the strained layer. Layers with the highest In concentration were fully relaxed.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director, Office of Science. Office of Basic Energy Studies. Division of Materials Sciences; National Science Foundation (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 771943
- Report Number(s):
- LBNL-46983; R&D Project: 513340; TRN: AH200108%%86
- Resource Relation:
- Conference: 11th International Semiconducting and Insulating Materials Conference (SIMC-XI 2000), Canberra (AU), 07/03/2000--07/07/2000; Other Information: PBD: 22 Nov 2000
- Country of Publication:
- United States
- Language:
- English
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