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Ultralow threading dislocation density in GaN epilayer on near-strain-free GaN compliant buffer layer and its applications in hetero-epitaxial LEDs.

Shih HY, Shiojiri M, Chen CH, Yu SF, Ko CT, Yang JR, Lin RM, Chen MJ - Sci Rep (2015)

Bottom Line: Here, we report InGaN/GaN LEDs with ultralow TD density and improved efficiency on a sapphire substrate, on which a near strain-free GaN compliant buffer layer was grown by remote plasma atomic layer deposition.This "compliant" buffer layer is capable of relaxing strain due to the absorption of misfit dislocations in a region within ~10 nm from the interface, leading to a high-quality overlying GaN epilayer with an unusual TD density as low as 2.2 × 10(5) cm(-2).In addition, this GaN compliant buffer layer exhibits excellent uniformity up to a 6" wafer, revealing a promising means to realize large-area GaN hetero-epitaxy for efficient LEDs and high-power transistors.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan.

ABSTRACT
High threading dislocation (TD) density in GaN-based devices is a long unresolved problem because of the large lattice mismatch between GaN and the substrate, which causes a major obstacle for the further improvement of next-generation high-efficiency solid-state lighting and high-power electronics. Here, we report InGaN/GaN LEDs with ultralow TD density and improved efficiency on a sapphire substrate, on which a near strain-free GaN compliant buffer layer was grown by remote plasma atomic layer deposition. This "compliant" buffer layer is capable of relaxing strain due to the absorption of misfit dislocations in a region within ~10 nm from the interface, leading to a high-quality overlying GaN epilayer with an unusual TD density as low as 2.2 × 10(5) cm(-2). In addition, this GaN compliant buffer layer exhibits excellent uniformity up to a 6" wafer, revealing a promising means to realize large-area GaN hetero-epitaxy for efficient LEDs and high-power transistors.

No MeSH data available.


Related in: MedlinePlus

XRD of the GaN epilayers.XRD rocking curves of (a) the symmetrical (002) and (b) symmetrical (102) reflections of the GaN epilayers grown on the ALD compliant BL and MOCVD NL.
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f5: XRD of the GaN epilayers.XRD rocking curves of (a) the symmetrical (002) and (b) symmetrical (102) reflections of the GaN epilayers grown on the ALD compliant BL and MOCVD NL.

Mentions: Figure 5 shows the (002) and (102) rocking curves of the GaN epilayers grown on ALD compliant BL and MOCVD NL, respectively. Both the (002) and (102) FWHM of the GaN on the ALD compliant BL (248.4 and 370.8 arcsec, respectively) are smaller than those of the GaN on the MOCVD NL (262.8 and 478.8 arcsec, respectively), which can be attributed to the decrease in TD density.


Ultralow threading dislocation density in GaN epilayer on near-strain-free GaN compliant buffer layer and its applications in hetero-epitaxial LEDs.

Shih HY, Shiojiri M, Chen CH, Yu SF, Ko CT, Yang JR, Lin RM, Chen MJ - Sci Rep (2015)

XRD of the GaN epilayers.XRD rocking curves of (a) the symmetrical (002) and (b) symmetrical (102) reflections of the GaN epilayers grown on the ALD compliant BL and MOCVD NL.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4556983&req=5

f5: XRD of the GaN epilayers.XRD rocking curves of (a) the symmetrical (002) and (b) symmetrical (102) reflections of the GaN epilayers grown on the ALD compliant BL and MOCVD NL.
Mentions: Figure 5 shows the (002) and (102) rocking curves of the GaN epilayers grown on ALD compliant BL and MOCVD NL, respectively. Both the (002) and (102) FWHM of the GaN on the ALD compliant BL (248.4 and 370.8 arcsec, respectively) are smaller than those of the GaN on the MOCVD NL (262.8 and 478.8 arcsec, respectively), which can be attributed to the decrease in TD density.

Bottom Line: Here, we report InGaN/GaN LEDs with ultralow TD density and improved efficiency on a sapphire substrate, on which a near strain-free GaN compliant buffer layer was grown by remote plasma atomic layer deposition.This "compliant" buffer layer is capable of relaxing strain due to the absorption of misfit dislocations in a region within ~10 nm from the interface, leading to a high-quality overlying GaN epilayer with an unusual TD density as low as 2.2 × 10(5) cm(-2).In addition, this GaN compliant buffer layer exhibits excellent uniformity up to a 6" wafer, revealing a promising means to realize large-area GaN hetero-epitaxy for efficient LEDs and high-power transistors.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan.

ABSTRACT
High threading dislocation (TD) density in GaN-based devices is a long unresolved problem because of the large lattice mismatch between GaN and the substrate, which causes a major obstacle for the further improvement of next-generation high-efficiency solid-state lighting and high-power electronics. Here, we report InGaN/GaN LEDs with ultralow TD density and improved efficiency on a sapphire substrate, on which a near strain-free GaN compliant buffer layer was grown by remote plasma atomic layer deposition. This "compliant" buffer layer is capable of relaxing strain due to the absorption of misfit dislocations in a region within ~10 nm from the interface, leading to a high-quality overlying GaN epilayer with an unusual TD density as low as 2.2 × 10(5) cm(-2). In addition, this GaN compliant buffer layer exhibits excellent uniformity up to a 6" wafer, revealing a promising means to realize large-area GaN hetero-epitaxy for efficient LEDs and high-power transistors.

No MeSH data available.


Related in: MedlinePlus