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Direct Growth and Controlled Coalescence of Thick AlN Template on Micro-circle Patterned Si Substrate.

Tran BT, Hirayama H, Maeda N, Jo M, Toyoda S, Kamata N - Sci Rep (2015)

Bottom Line: High-density micro-circle patterned Si substrates were successfully fabricated for the direct overgrowth of thick AlN templates by using NH3 pulsed-flow multilayer AlN growth and epitaxial lateral overgrowth techniques.The experimental results show that an 8-μm-thick AlN template was grown at a very high growth rate on the substrates.The AlN template had full widths at half maximum of 0.23° and 0.37° for the (002) and (102) reflection planes in X-ray diffraction rocking curves.

View Article: PubMed Central - PubMed

Affiliation: Quantum Optodevice Laboratory, Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.

ABSTRACT
High-density micro-circle patterned Si substrates were successfully fabricated for the direct overgrowth of thick AlN templates by using NH3 pulsed-flow multilayer AlN growth and epitaxial lateral overgrowth techniques. The experimental results show that an 8-μm-thick AlN template was grown at a very high growth rate on the substrates. The AlN template had full widths at half maximum of 0.23° and 0.37° for the (002) and (102) reflection planes in X-ray diffraction rocking curves. Atomic force microscopy and transmission electron microscopy confirmed that the roughness of the surface was low (3.5 nm) and the dislocation density was very low (1.5 × 10(8) cm(-2) (screw), 3.7 × 10(8) (edge) cm(-2)).

No MeSH data available.


Related in: MedlinePlus

Cross-sectional SEM images show the excellent coalescence thickness of sample C compared with samples A, B, and D.
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f3: Cross-sectional SEM images show the excellent coalescence thickness of sample C compared with samples A, B, and D.

Mentions: Figure 3 shows cross-sectional SEM images of samples A–D. Samples A and B, which had a first AlN layer grown for 5 and 8 min, respectively, revealed that the both surfaces were either facetted and rough, or no coalescence thickness was achieved (Fig. 3(a,b)). For samples C and D, coalescence thickness was achieved and increased quickly for the two samples with smooth surfaces as confirmed by AFM measurements. However, the XRD results confirmed that the crystallinity of sample C was higher than that of sample D, which may be caused by the surface of sample D being worse than that of sample C. The surface roughness of samples C and D were 3.5 and 7.7 nm, respectively, as measured by AFM (images not shown), whereas samples A and B had surface roughnesses of 132 and 98 nm, respectively. In addition, there were no cracks on the surface of all samples were observed, even though they all were grown at very high temperatures, which usually causes cracking during cooling because of thermally induced tensile stress7.


Direct Growth and Controlled Coalescence of Thick AlN Template on Micro-circle Patterned Si Substrate.

Tran BT, Hirayama H, Maeda N, Jo M, Toyoda S, Kamata N - Sci Rep (2015)

Cross-sectional SEM images show the excellent coalescence thickness of sample C compared with samples A, B, and D.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4593966&req=5

f3: Cross-sectional SEM images show the excellent coalescence thickness of sample C compared with samples A, B, and D.
Mentions: Figure 3 shows cross-sectional SEM images of samples A–D. Samples A and B, which had a first AlN layer grown for 5 and 8 min, respectively, revealed that the both surfaces were either facetted and rough, or no coalescence thickness was achieved (Fig. 3(a,b)). For samples C and D, coalescence thickness was achieved and increased quickly for the two samples with smooth surfaces as confirmed by AFM measurements. However, the XRD results confirmed that the crystallinity of sample C was higher than that of sample D, which may be caused by the surface of sample D being worse than that of sample C. The surface roughness of samples C and D were 3.5 and 7.7 nm, respectively, as measured by AFM (images not shown), whereas samples A and B had surface roughnesses of 132 and 98 nm, respectively. In addition, there were no cracks on the surface of all samples were observed, even though they all were grown at very high temperatures, which usually causes cracking during cooling because of thermally induced tensile stress7.

Bottom Line: High-density micro-circle patterned Si substrates were successfully fabricated for the direct overgrowth of thick AlN templates by using NH3 pulsed-flow multilayer AlN growth and epitaxial lateral overgrowth techniques.The experimental results show that an 8-μm-thick AlN template was grown at a very high growth rate on the substrates.The AlN template had full widths at half maximum of 0.23° and 0.37° for the (002) and (102) reflection planes in X-ray diffraction rocking curves.

View Article: PubMed Central - PubMed

Affiliation: Quantum Optodevice Laboratory, Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.

ABSTRACT
High-density micro-circle patterned Si substrates were successfully fabricated for the direct overgrowth of thick AlN templates by using NH3 pulsed-flow multilayer AlN growth and epitaxial lateral overgrowth techniques. The experimental results show that an 8-μm-thick AlN template was grown at a very high growth rate on the substrates. The AlN template had full widths at half maximum of 0.23° and 0.37° for the (002) and (102) reflection planes in X-ray diffraction rocking curves. Atomic force microscopy and transmission electron microscopy confirmed that the roughness of the surface was low (3.5 nm) and the dislocation density was very low (1.5 × 10(8) cm(-2) (screw), 3.7 × 10(8) (edge) cm(-2)).

No MeSH data available.


Related in: MedlinePlus