Effect of defects on strain state in nonpolar a-plane GaN

Liu, Z.Y.; Xu, Shengrui; Zhang, J.C.; Xue, JunShuai; Xue, Xiaoxiao; Niu, Mu

doi:10.1016/j.jcrysgro.2012.01.001

Cited by 6 publications

(3 citation statements)

References 29 publications

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“…Some groups reported that the strain relaxation in non-polar a-GaN can be attributed to the formation of the BSFs. [21,22] So for samples E and F, with high density BSFs, the strain is greatly released.…”

Section: Resultsmentioning

confidence: 99%

Effects of V/III ratio on a -plane GaN epilayers with an InGaN interlayer

Wang¹,

Wang²,

Yang³

et al. 2014

Chinese Phys. B

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The effects of V/III growth flux ratio on a-plane GaN films grown on r-plane sapphire substrates with an InGaN interlayer are investigated. The surface morphology, crystalline quality, strain states, and density of basal stacking faults were found to depend heavily upon the V/III ratio. With decreasing V/III ratio, the surface morphology and crystal quality first improved and then deteriorated, and the density of the basal-plane stacking faults also first decreased and then increased. The optimal V/III ratio growth condition for the best surface morphology and crystalline quality and the smallest basalplane stacking fault density of a-GaN films are found. We also found that the formation of basal-plane stacking faults is an effective way to release strain.

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Section: Resultsmentioning

confidence: 99%

Effects of V/III ratio on a -plane GaN epilayers with an InGaN interlayer

Wang¹,

Wang²,

Yang³

et al. 2014

Chinese Phys. B

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“…52 In addition, large densities of dislocations and other defects are expected to occur and to favor the diffusion losses. 52,64,65 Third, if the sputtering deposition and the analysis of ion impingement are considered, tensile microstresses could be generated in the GaN films because of the inclusion of N as an interstitial (the energy of the reflected N is enough to produce this effect). Nevertheless, according to this argument, it is expected that the samples deposited at lower temperatures should also exhibit a pronounced tensile effect, but this was not observed in the present data.…”

Section: Discussionmentioning

confidence: 99%

Effects of substrate temperature, substrate orientation, and energetic atomic collisions on the structure of GaN films grown by reactive sputtering

Schiaber

Leite

Bortoleto

et al. 2013

Journal of Applied Physics

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Growth stresses and cracking in GaN films on (111) The combined effects of substrate temperature, substrate orientation, and energetic particle impingement on the structure of GaN films grown by reactive radio-frequency magnetron sputtering are investigated. Monte-Carlo based simulations are employed to analyze the energies of the species generated in the plasma and colliding with the growing surface. Polycrystalline films grown at temperatures ranging from 500 to 1000 C clearly showed a dependence of orientation texture and surface morphology on substrate orientation (c-and a-plane sapphire) in which the (0001) GaN planes were parallel to the substrate surface. A large increase in interplanar spacing associated with the increase in both a-and c-parameters of the hexagonal lattice and a redshift of the optical bandgap were observed at substrate temperatures higher than 600 C. The results showed that the tensile stresses produced during the film's growth in high-temperature deposition ranges were much larger than the expected compressive stresses caused by the difference in the thermal expansion coefficients of the film and substrate in the cool-down process after the film growth. The best films were deposited at 500 C, 30 W and 600 C, 45 W, which corresponds to conditions where the out diffusion from the film is low. Under these conditions the benefits of the temperature increase because of the decrease in defect density are greater than the problems caused by the strongly strained lattice that occurr at higher temperatures. The results are useful to the analysis of the growth conditions of GaN films by reactive sputtering. V C 2013 AIP Publishing LLC.

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“…On the other hand, non-polar (like mor a-plane) [11][12][13][14][15][16] or semi-polar [17][18][19][20][21] heteroepitaxial III-nitride systems have been used for optoelectronic devices in order to avoid the occurrence of a piezoelectric field at the heterointerface. During non-polar or semi-polar heteroepitaxial growth, however, the occurrence of stacking faults (SFs) and their transmission to the epitaxial layers have led to other problems.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of a-type screw dislocations inm-GaN film by means of X-ray diffractometry

Hiraiwa

Liu

Shibata

et al. 2015

Jpn. J. Appl. Phys.

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Dislocations in an epitaxial GaN film with a surface (m-GaN) were investigated by means of X-ray diffractometry. It was clarified that a-type screw dislocations existed in the sample by evaluating diffraction contrast on X-ray topographs (XRTs). In addition, local lattice inclinations of the plane toward the [0001] direction were observed with spatial intervals similar to the separation distances of those a-type screw dislocations slipping on the (0001) basal plane and also on other cross-slip planes in the sample.

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Effect of defects on strain state in nonpolar a-plane GaN

Cited by 6 publications

References 29 publications

Effects of V/III ratio on a -plane GaN epilayers with an InGaN interlayer

Effects of V/III ratio on a -plane GaN epilayers with an InGaN interlayer

Effects of substrate temperature, substrate orientation, and energetic atomic collisions on the structure of GaN films grown by reactive sputtering

Evaluation of a-type screw dislocations inm-GaN film by means of X-ray diffractometry

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