Limits...
Microstructure of non-polar GaN on LiGaO2 grown by plasma-assisted MBE.

Shih CH, Huang TH, Schuber R, Chen YL, Chang L, Lo I, Chou MM, Schaadt DM - Nanoscale Res Lett (2011)

Bottom Line: The already reported epi-taxial relationship and for M -plane GaN is confirmed.For the M -plane sample, the density of threading dislocations is around 1 × 1011 cm-2 and the stacking fault density amounts to approximately 2 × 105 cm-1.In the A-plane sample, a threading dislocation density in the same order was found, while the stacking fault density is much lower than in the M -plane sample.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Applied Physics/DFG-Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany. ralf.schuber@kit.edu.

ABSTRACT
We have investigated the structure of non-polar GaN, both on the M - and A-plane, grown on LiGaO2 by plasma-assisted molecular beam epitaxy. The epitaxial relationship and the microstructure of the GaN films are investigated by transmission electron microscopy (TEM). The already reported epi-taxial relationship and for M -plane GaN is confirmed. The main defects are threading dislocations and stacking faults in both samples. For the M -plane sample, the density of threading dislocations is around 1 × 1011 cm-2 and the stacking fault density amounts to approximately 2 × 105 cm-1. In the A-plane sample, a threading dislocation density in the same order was found, while the stacking fault density is much lower than in the M -plane sample.

No MeSH data available.


Related in: MedlinePlus

Inplane TEM sample of the M -plane GaN sample. The inset shows the GaN diffraction pattern.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211842&req=5

Figure 3: Inplane TEM sample of the M -plane GaN sample. The inset shows the GaN diffraction pattern.

Mentions: The plan view TEM sample of the M -plane GaN film allows for an estimate of the density of threading dislocations and stacking faults. A centered dark field image of one region of the plan view sample is seen in Figure 3. The numerous small dots represent threading dislocations, while stacking faults are found running perpendicular to the [0001] direction as indicated, i.e., they lie in the C -plane. The elongated spots in the diffraction pattern inset in Figure 3 point toward the presence of twisted mosaic blocks in the film. The twist angle can be as high as 5°. In this sample, the threading dislocation density was found to be on the order of 1 × 1011 cm-2 and the stacking fault density around 2 × 105 cm-1. The dislocation density is higher in this sample than values reported in the literature ~ 109 cm-2 [4] for M -plane GaN, e.g. grown on LiAlO2 by MOVPE. However, growth parameters had not been fully optimized on LGO and the film thickness here is twice as thin as in [4]. The thickness of the film is believed to have some impact on the threading dislocation density as is mentioned in [5] where the values for M -plane GaN grown on LiAlO2 are given as 109 cm-2 near the substrate and 108 cm-2 near the surface. The stacking fault density in our sample is roughly on the same order as reported elsewhere; however, values as low as 104 cm-1 [4] have been reported.


Microstructure of non-polar GaN on LiGaO2 grown by plasma-assisted MBE.

Shih CH, Huang TH, Schuber R, Chen YL, Chang L, Lo I, Chou MM, Schaadt DM - Nanoscale Res Lett (2011)

Inplane TEM sample of the M -plane GaN sample. The inset shows the GaN diffraction pattern.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211842&req=5

Figure 3: Inplane TEM sample of the M -plane GaN sample. The inset shows the GaN diffraction pattern.
Mentions: The plan view TEM sample of the M -plane GaN film allows for an estimate of the density of threading dislocations and stacking faults. A centered dark field image of one region of the plan view sample is seen in Figure 3. The numerous small dots represent threading dislocations, while stacking faults are found running perpendicular to the [0001] direction as indicated, i.e., they lie in the C -plane. The elongated spots in the diffraction pattern inset in Figure 3 point toward the presence of twisted mosaic blocks in the film. The twist angle can be as high as 5°. In this sample, the threading dislocation density was found to be on the order of 1 × 1011 cm-2 and the stacking fault density around 2 × 105 cm-1. The dislocation density is higher in this sample than values reported in the literature ~ 109 cm-2 [4] for M -plane GaN, e.g. grown on LiAlO2 by MOVPE. However, growth parameters had not been fully optimized on LGO and the film thickness here is twice as thin as in [4]. The thickness of the film is believed to have some impact on the threading dislocation density as is mentioned in [5] where the values for M -plane GaN grown on LiAlO2 are given as 109 cm-2 near the substrate and 108 cm-2 near the surface. The stacking fault density in our sample is roughly on the same order as reported elsewhere; however, values as low as 104 cm-1 [4] have been reported.

Bottom Line: The already reported epi-taxial relationship and for M -plane GaN is confirmed.For the M -plane sample, the density of threading dislocations is around 1 × 1011 cm-2 and the stacking fault density amounts to approximately 2 × 105 cm-1.In the A-plane sample, a threading dislocation density in the same order was found, while the stacking fault density is much lower than in the M -plane sample.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Applied Physics/DFG-Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany. ralf.schuber@kit.edu.

ABSTRACT
We have investigated the structure of non-polar GaN, both on the M - and A-plane, grown on LiGaO2 by plasma-assisted molecular beam epitaxy. The epitaxial relationship and the microstructure of the GaN films are investigated by transmission electron microscopy (TEM). The already reported epi-taxial relationship and for M -plane GaN is confirmed. The main defects are threading dislocations and stacking faults in both samples. For the M -plane sample, the density of threading dislocations is around 1 × 1011 cm-2 and the stacking fault density amounts to approximately 2 × 105 cm-1. In the A-plane sample, a threading dislocation density in the same order was found, while the stacking fault density is much lower than in the M -plane sample.

No MeSH data available.


Related in: MedlinePlus