Effect of AlN/GaN superlattice buffer on the strain state in GaN-on-Si(111) system

Ni, Yiqiang; He, Zhiyuan; Yang, Fan; Zhou, Davis B.; Yao, Yao; Zhou, Guocheng; Shen, Zhen; Zhong, Jiaming; Zhen, Yue; Wu, Zhisheng; Zhang, Baijun; Liu, Yang

doi:10.7567/jjap.54.015505

Cited by 34 publications

(19 citation statements)

References 30 publications

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“…The out-of-plane strain along the [11–20] direction is in a tensile state and changes to a compressive state once the number of SSPM-L AlN/GaN pairs reaches 120, as shown in Table 3 . These results are in good agreement with a report by Yiqiang et al that increasing the number of AlN/GaN pairs changes the strain state of the GaN surface from tensile to compressive 36 .…”

Section: Resultssupporting

confidence: 93%

Impact of sandwiched strain periodic multilayer AlN/GaN on strain and crystalline quality of a-plane GaN

Kamarundzaman

Shuhaimi

Azman

et al. 2021

Sci Rep

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We demonstrated high-quality single crystalline a-plane undoped-gallium nitride grown on a nonpatterned r-plane sapphire substrate via metal–organic chemical vapor deposition. The effect of four different numbers of sandwiched strain-periodic AlN/GaN multilayers on the strain state, crystal quality, optical and electrical properties was investigated. Field emission scanning electron microscopy and atomic force microscopy showed that the surface morphology was improved upon insertion of 120 pairs of AlN/GaN thin layers with a root-mean-square roughness of 2.15 nm. On-axis X-ray ω-scan rocking curves showed enhanced crystalline quality: the full width at half maximum decreased from 1224 to 756 arcsec along the [0001] direction and from 2628 to 1360 arcsec along the [1–100] direction for a-GaN grown with 120 pairs of AlN/GaN compared to a-GaN without AlN/GaN pairs. Reciprocal space mapping showed that a-plane GaN with a high number of AlN/GaN pairs exhibits near-relaxation strain states. Room-temperature photoluminescence spectra showed that the sample with the highest number of AlN/GaN pairs exhibited the lowest-intensity yellow and blue luminescence bands, indicating a reduction in defects and dislocations. The a-plane InGaN/GaN LEDs with 120 pairs of SSPM-L AlN/GaN exhibited a significant increase (~ 250%) in light output power compared to that of LEDs without SSPM-L AlN/GaN pairs.

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Section: Resultssupporting

confidence: 93%

Impact of sandwiched strain periodic multilayer AlN/GaN on strain and crystalline quality of a-plane GaN

Kamarundzaman

Shuhaimi

Azman

et al. 2021

Sci Rep

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“…The last type of strain engineered layer was a GaN/AlN superlattice, which has been recently employed for the growth of even thicker GaN layers on silicon . In experiment J a low temperature was adopted, while in exp.…”

Section: Resultsmentioning

confidence: 99%

Suppression of Iron Memory Effect in GaN Epitaxial Layers

Benkhelifa

Kirste

Manz

et al. 2017

Physica Status Solidi (b)

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AlGaN/GaN High Electron Mobility Transistors (HEMTs) require a semi‐insulating buffer to compensate a high background donor concentration and to prevent parasitic effects, such as parallel conduction. Iron and carbon are typical impurities used for such purpose, since they can behave as deep acceptors in GaN layers. The former (Fe) brings as drawback a well‐known memory effect which consists in the segregation of Fe atoms through the GaN layers, requiring thick undoped layers to keep the two‐dimensional electron gas (2DEG) away from such electron traps. The latter (C), although easier to incorporate in the GaN layers and free of any memory effect, could cause current collapse. In this study we investigate the effect of differently strained epitaxial layers on Fe‐segregation. HEMT structures were grown on sapphire substrates by MOCVD. By growing the Fe‐doped layers under unusual growth conditions (low temperature, or as AlGaN), or by adding an interlayer (AlN, 5× AlN/GaN, or C‐doped GaN) between the doped and undoped epitaxial layers, we have succeeded in limiting the Fe segregation within 200 nm of undoped GaN layer instead of the typically required 800 nm, as proven by SIMS. While the morphology and the crystal quality of the HEMT structures have been affected to a very low extent, the electrical characteristics have benefitted from such interlayers. Higher carrier mobility and lower sheet resistance distinguish such epitaxial structures. Further benefits are expected by the device performance such as reduced soft‐subthreshold behavior (soft‐breakdown) and dispersion effects.

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“…Therefore, many researchers have introduced various methods to reduce threading dislocation, stress mitigation, and remove cracks, such as epitaxial lateral overgrowth, nanoporous GaN layers, graded AlGaN interlayers, and Al(Ga)N/GaN superlattices [ 12 , 13 , 14 , 15 ]. Particularly, the AlN layer, which acts as a bottom buffer layer on the Si substrate, significantly affects crystalline quality and stress management of the GaN layer.…”

Section: Introductionmentioning

confidence: 99%

Improved Performance of GaN-Based Light-Emitting Diodes Grown on Si (111) Substrates with NH3 Growth Interruption

Kim

Lee

et al. 2021

Micromachines

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We demonstrate the highly efficient, GaN-based, multiple-quantum-well light-emitting diodes (LEDs) grown on Si (111) substrates embedded with the AlN buffer layer using NH3 growth interruption. Analysis of the materials by the X-ray diffraction omega scan and transmission electron microscopy revealed a remarkable improvement in the crystalline quality of the GaN layer with the AlN buffer layer using NH3 growth interruption. This improvement originated from the decreased dislocation densities and coalescence-related defects of the GaN layer that arose from the increased Al migration time. The photoluminescence peak positions and Raman spectra indicate that the internal tensile strain of the GaN layer is effectively relaxed without generating cracks. The LEDs embedded with an AlN buffer layer using NH3 growth interruption at 300 mA exhibited 40.9% higher light output power than that of the reference LED embedded with the AlN buffer layer without NH3 growth interruption. These high performances are attributed to an increased radiative recombination rate owing to the low defect density and strain relaxation in the GaN epilayer.

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Effect of AlN/GaN superlattice buffer on the strain state in GaN-on-Si(111) system

Cited by 34 publications

References 30 publications

Impact of sandwiched strain periodic multilayer AlN/GaN on strain and crystalline quality of a-plane GaN

Impact of sandwiched strain periodic multilayer AlN/GaN on strain and crystalline quality of a-plane GaN

Suppression of Iron Memory Effect in GaN Epitaxial Layers

Improved Performance of GaN-Based Light-Emitting Diodes Grown on Si (111) Substrates with NH3 Growth Interruption

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