TEM and XANES study of MOVPE grown InAIN layers with different indium content

Kret, S.; Wolska, A.; Klepka, Marcin T.; Letrouit, A; Ivaldi, F.; Szczepańska, Alicja; Carlin, J.‐F.; Kaufmann, Nils Asmus Kristian; Grandjean, N.

doi:10.1088/1742-6596/326/1/012013

Cited by 9 publications

(9 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Fig. 1 , the equilibrium solubility of the two binary compounds in InAlN is nearly 0, and the maximal metastable solubility is around 10% at the temperature most common for the epitaxial growth of InAlN (1000 K 28 29 ): it is a little less than 10% for Model A, and a little more than 10% for Model D2, actually. These results indicate that InAlN alloys are unstable over most of the composition range at normal growth temperatures without the mismatch strain.…”

Section: Resultsmentioning

confidence: 90%

“…Whether phase separation occurs or not for an experimental data is related to both of the fully relaxed curve and the fully strained one. Our result corresponds to Hums et al .’s 28 and Kret et al .’s 29 experimental data. In the experiments, InAlN/GaN (sub) samples with a growth temperature range of 760 °C–860 °C and an In content of 0.13 < x < 0.32 show no phase separation (the circles in Fig.…”

Section: Resultsmentioning

confidence: 99%

“… The data from refs 28 and 29 are plotted as circles for homogeneous and squares for phase separated InAlN, respectively. …”

Section: Figurementioning

confidence: 99%

See 2 more Smart Citations

The immiscibility of InAlN ternary alloy

Zhao

et al. 2016

Sci Rep

View full text Add to dashboard Cite

We have used two models based on the valence force field and the regular solution model to study the immiscibility of InAlN ternary alloy, and have got the spinodal and binodal curves of InAlN. Analyzing the spinodal decomposition curves, we obtain the appropriate concentration region for the epitaxial growth of the InN-AlN pseudobinary alloy. At a temperature most common for the epitaxial growth of InAlN (1000 K), the solubility of InN is about 10%. Then we introduce the mismatch strain item into the Gibbs free energy, and the effect of different substrates is taken into consideration. Considering Si, Al2O3, InN, GaN, AlN as a substrate respectively, it is found that all the five systems are stabilized with the upper critical solution temperature largely reduced. Finally, InN and GaN are potential substrates for In-rich InAlN, while AlN and GaN substrates are recommended in the Al-rich region. Si and Al2O3 may be ideal substrates for thin InAlN film.

show abstract

Section: Resultsmentioning

confidence: 90%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

The immiscibility of InAlN ternary alloy

Zhao

et al. 2016

Sci Rep

View full text Add to dashboard Cite

show abstract

“…24 Thus homogeneous layers with a given composition give birth to an upper layer with a higher or a lower indium composition. [25][26][27][28][29][30] Some authors have proposed a mechanism for this degradation occurring with increasing thickness. 29,30 It was suggested that threading dislocations due to the heteroepitaxial growth of the GaN template on sapphire were the only cause for the formation of V-defects.…”

Section: Latelymetalorganic Vapor Phase Epitaxy (Movpe) Is the Commomentioning

confidence: 99%

Intrinsic degradation mechanism of nearly lattice-matched InAlN layers grown on GaN substrates

Perillat-Merceroz

Cosendey

Carlin

et al. 2013

Journal of Applied Physics

View full text Add to dashboard Cite

Thanks toits high refractive index contrast, band gap and polarization mismatch compared to GaN, In 0.17 Al 0.83 N layers lattice-matched to GaN are an attractive solution for applications such as distributed Bragg reflectors, ultraviolet light-emitting diodes, orhigh electron mobility transistors. In order to study the structural degradation mechanism of InAlN layers with increasing thickness, we performed metalorganic vapor phase epitaxy of InAlN layers of thicknesses ranging from 2 to 500 nm, on free-standing (0001) GaN substrates with a low density of threading dislocations, for In compositions of 13.5% (layers under tensile strain), and 19.7%(layers under compressive strain). In both cases, a surface morphology with hillocks isinitially observed, followed by the appearance of V-defects. We propose that those hillocks arise due to kinetic roughening, and that V-defects subsequently appear beyonda critical hillock size. It is seen that the critical thickness for the appearance of V-defects increases together with the surface diffusion length either by increasing the temperature or the In flux because of asurfactant effect.In thick InAlN layers, a better (worse) In incorporation occurring on the concave (convex) shape surfaces of the V-defects is observed leading to a top phase-separated InAlN layer lying on the initial homogeneous InAlN layerafterV-defects coalescence.It is suggested that similar mechanisms could be responsible for the degradation of thick InGaN layers.

show abstract

“…This result indicates that the resistivity of the InAlN layer itself is locally much lower than other areas, indicating the existence of a nanometer scale material fluctuation. We consider that the most possible material fluctuation occurring in InAlN is that of the indium composition fluctuation, and this has been experimentally confirmed by several groups [15][16][17]. The indium-rich region results in a lower Schottky barrier height because of a higher electron affinity, and the 2DEG density is thus reduced due to lower spontaneous and piezoelectric polarization charges.…”

Section: Direct Observation Of Nanometer-scale Leakage Paths In Alganmentioning

confidence: 76%

Direct observation of nanometer-scale gate leakage paths in AlGaN/GaN and InAlN/AlN/GaN HEMT structures

Kotani

Yamada

Ishiguro

et al. 2016

Phys. Status Solidi A

View full text Add to dashboard Cite

This paper investigates the effects of MOVPE growth parameters on the gate leakage characteristics of InAlN HEMT structures and compares leakage current paths in AlGaN and InAlN HEMT structures on a nanometer scale. The gate leakage characteristics of AlGaN and InAlN HEMT were compared, and the large leakage current in InAlN HEMT was found to result from the high‐density 2DEG‐induced strong electric field accumulation in the barrier layer. Both the increasing growth rate and decreasing growth temperature in the InAIN layer of InAlN HEMT caused the deterioration of gate leakage characteristics and surface morphologies. Conductive AFM measurements were performed for AlGaN and InAlN HEMT structures, and a one‐to‐one clear correlation between surface pits and leakage paths was found for AlGaN HEMT. On the contrary, for the InAlN HEMT grown at a low temperature, high‐density localized leakage paths were observed. We believe the observed leakage paths originate from nanometer‐scale material fluctuations, which is most likely an indium composition fluctuation. Our results indicate that it is necessary to grow the InAlN barrier layer at 740 °C or higher and that the growth rate must be 1.25 nm min−1 or less to realize low‐gate leakage in InAlN HEMT. A further reduction of the gate leakage current requires the reduction of the dislocation density and use of gate insulators.

show abstract

TEM and XANES study of MOVPE grown InAIN layers with different indium content

Cited by 9 publications

References 3 publications

The immiscibility of InAlN ternary alloy

The immiscibility of InAlN ternary alloy

Intrinsic degradation mechanism of nearly lattice-matched InAlN layers grown on GaN substrates

Direct observation of nanometer-scale gate leakage paths in AlGaN/GaN and InAlN/AlN/GaN HEMT structures

Contact Info

Product

Resources

About