- Nano Express
- Open Access
Structural properties of Al-rich AlInN grown on c-plane GaN substrate by metal-organic chemical vapor deposition
© Lin et al.; licensee Springer. 2014
- Received: 30 June 2014
- Accepted: 17 November 2014
- Published: 23 November 2014
The attractive prospect for AlInN/GaN-based devices for high electron mobility transistors with advanced structure relies on high-quality AlInN epilayer. In this work, we demonstrate the growth of high-quality Al-rich AlInN films deposited on c-plane GaN substrate by metal-organic chemical vapor deposition. X-ray diffraction, scanning electron microscopy, and scanning transmission electron microscopy show that the films lattice-matched with GaN can have a very smooth surface with good crystallinity and uniform distribution of Al and In in AlInN.
- Metal-organic chemical vapor deposition
AlInN is a newly developed III-nitride for many promising applications due to its band gap being able to be tuned in a wide range of 0.70 ~ 6.14 eV with high spontaneous polarization[1–3]. AlInN/GaN heterojunction has been suggested as a strong candidate for high-power and high-frequency applications owing to the nearly lattice match (In = 0.17) and stress-free heterostructure in which the piezoelectric polarization charge is eliminated to reduce surface-related current collapse[4–8]. The attractive prospect for AlInN/GaN-based devices for high electron mobility transistors with advanced structure relies on high-quality AlInN epilayer. However, many properties of ternary AlInN alloys have not been well understood because of lack of high-quality films. Growth of AlInN is complicated by thermal control, which usually results in growth with composition inhomogeneities and phase separation[9–11]. Especially, the thermal instability may lead to phase separations and other defects which form on the substrate and may evolve during the growth resulting in rough and poorly uniform surface. The lattice-matched of high-quality AlInN can potentially lead to a reduction in threading dislocation and cracking as well as the elimination of strain-driven piezoelectric polarization field.
Various growth techniques have been used for growth of AlInN films, such as metal-organic chemical vapor deposition (MOCVD), radio-frequency molecular beam epitaxy, pulse laser deposition, and magnetron sputtering on c-plane sapphire substrates[13–15]. In the past few years, most of AlInN/GaN studies are done on films grown on sapphire substrate which has strong effects on the film properties, and among them, lattice-matched Al1-xIn x N/GaN with 0.17 ~ x ~ 0.18 has received intensive attention[16–18]. The nearly lattice-matched AlInN layer grown on GaN/sapphire substrate usually contain some defects like hillocks, dislocations natively present in the GaN layer and the V-defects on GaN surface[19–21]. However, recent studied show that the growth of AlInN on GaN remains a challenge as many issues have to be addressed[22, 23]. Hereinafter, we show that a high-quality and smooth Al1-xIn x N film with x less than 0.17 can be epitaxially grown on GaN free-standing substrate with in-plane lattice match by employing MOCVD.
In this work, we used hydride vapor phase epitaxy (HVPE)-grown GaN wafers as substrates which had a 1.5-in. diameter and 300-μm thickness with a full width at half maximum (FWHM) of the (0002) X-ray rocking curve (XRC) 100 arcsec (dislocation density approximately 1 × 107 cm-2) and a root mean square (RMS) surface roughness of 1.23 nm. A 1.5-μm-thick homoepitaxial GaN film was firstly grown on GaN substrate at 970°C by MOCVD (Veeco Emcore D-180; Veeco Instruments Inc., Plainview, NY, USA) using TMGa and NH3 as the precursors for Ga and N to improve GaN crystallinity. After the growth of GaN layer, TMAl and NH3 were flowed into the chamber at 990°C for 1 min, followed by further growth of AlInN epilayer at temperature of 780 and 800°C. A TMAl/TMIn ratio of 1/10, a reactor pressure of 100 Torr, and a NH3 flow rate of 15,000 sccm were used for all AlInN growth.
The crystallinities of the samples were examined with high-resolution X-ray diffraction (XRD, Bruker D8; Bruker Corp., Billerica, MA, USA), and the surface morphologies were investigated by scanning electron microscopy (SEM, JEOL JSM-6500F; JEOL Ltd., Akishima, Tokyo, Japan) and atomic force microscopy (AFM, Veeco Innova). Structural characterization at atomic scale was performed in a JEOL JEM-ARM200F spherical aberration corrected scanning transmission electron microscope (STEM) in high-angle annular dark field (HAADF) imaging mode, operated at 200 kV. Cross-sectional transmission electron microscopy specimens were prepared in a focused ion beam system (FEI NOVA-200; FEI Company, Hillsboro, OR, USA) using a 30-kV Ga+ source.
The above results show that lattice-matched Al1-xIn x N films on GaN with x < 0.17 are of high crystallinity with quite smooth surface, which can be comparable with those of Al1-xIn x N films grown on free-standing GaN substrates with x close to 0.17.
In this work, we successfully fabricated high-quality AlInN/GaN heterostructures by MOCVD. XRD, SEM, and STEM results reveal that the film is of good crystallinity and uniformity in composition, smooth surface flatness, and the abrupt heterointerface with lattice-matched AlInN epilayer on free-standing GaN substrate at atomic scale.
This work was supported by the Ministry of Science and Technology of Taiwan (NSC 101-2221-E-009-050-MY3), the Ministry of Economic Affairs of Taiwan (102-EC-17-A-05-S1-154), and National Chiao Tung University (103 W974).
- Lorenz K, Franco N, Alves E, Watson IM, Martin RW, O’Donnell KP: Anomalous ion channeling in AlInN/GaN bilayers: determination of the strain state. Phys Rev Lett 2006, 97: 085501.View ArticleGoogle Scholar
- Rinke P, Winkelnkemper M, Qteish A, Bimberg D, Neugebauer J, Scheffler M: Consistent set of band parameters for the group-III nitrides AlN, GaN, and InN. Phys Rev B 2008, 77: 075202.View ArticleGoogle Scholar
- Gonschorek M, Carlin JF, Feltin E, Py MA, Grandjean N, Darakchieva V, Monemar B, Lorenz M, Ramm G: Two-dimensional electron gas density in Al(1-x) In(x) N/AlN/GaN heterostructures (0.03 <= x <= 0.23). J Appl Phys 2008, 103: 093714. 10.1063/1.2917290View ArticleGoogle Scholar
- Khan MA, Bhattarai A, Kuznia JN, Olson DT: High-electron-mobility transistor based on a GaN-AlxGa1-xN heterojunction. Appl Phys Lett 1993, 63: 1214–1215. 10.1063/1.109775View ArticleGoogle Scholar
- Someya T, Werner R, Forchel A, Catalano M, Cingolani R, Arakawa Y: Room temperature lasing at blue wavelengths in gallium nitride microcavities. Science 1999, 285: 1905–1906. 10.1126/science.285.5435.1905View ArticleGoogle Scholar
- Mishra UK, Parikh P, Wu YF: AlGaN/GaN HEMTs - an overview of device operation and applications. Proc IEEE 2002, 90: 1022–1031. 10.1109/JPROC.2002.1021567View ArticleGoogle Scholar
- Trew RJ, Bilbro GL, Kuang W, Liu Y, Yin H: Microwave AlGaN/GaN HFETs. IEEE Microw Mag 2005, 6: 56–66.View ArticleGoogle Scholar
- Sakalauskas E, Behmenburg H, Hums C, Schley P, Rossbach G, Giesen C, Heuken M, Kalisch H, Jansen RH, Blasing J, Dadgar A, Krost A, Goldhahn R: Dielectric function and optical properties of Al-rich AlInN alloys pseudomorphically grown on GaN. J Phys D Appl Phys 2010, 43: 365102. 10.1088/0022-3727/43/36/365102View ArticleGoogle Scholar
- Hums C, Bläsing J, Dadgar A, Diez A, Hempel T, Christen J, Krost A, Lorenz K, Alves E: Metal-organic vapor phase epitaxy and properties of AlInN in the whole compositional range. Appl Phys Lett 2007, 90: 022105. 10.1063/1.2424649View ArticleGoogle Scholar
- Gadanecz A, Bläsing J, Dadgar A, Hums C, Krost A: Thermal stability of metal organic vapor phase epitaxy grown AlInN. Appl Phys Lett 2007, 90: 221906. 10.1063/1.2743744View ArticleGoogle Scholar
- Sadler TC, Kappers MJ, Oliver RA: The effects of varying metal precursor fluxes on the growth of InAlN by metal organic vapour phase epitaxy. J Cryst Growth 2011, 314: 13–20. 10.1016/j.jcrysgro.2010.10.108View ArticleGoogle Scholar
- Dadgar A, Schulze F, Bläsing J, Diez A, Krost A, Neuburger M, Kohn E, Daumiller I, Kunze M: High-sheet-charge-carrier-density AlInN/GaN field-effect transistors on Si(111). Appl Phys Lett 2004, 85: 5400–5402. 10.1063/1.1828580View ArticleGoogle Scholar
- Guo QX, Tanaka T, Nishio M, Ogawa H: Structural and optical properties of AlInN films grown on sapphire substrates. Jpn J Appl Phys 2008, 47: 612–615. 10.1143/JJAP.47.612View ArticleGoogle Scholar
- Kim-Chauveau H, de Mierry P, Chauveau JM, Duboz JY: The influence of various MOCVD parameters on the growth of Al1-xInxN ternary alloy on GaN templates. J Cryst Growth 2011, 316: 30–36. 10.1016/j.jcrysgro.2010.12.040View ArticleGoogle Scholar
- Chen WC, Wu YH, Peng CY, Hsiao CN, Chang L: Effect of In/Al ratios on structural and optical properties of InAlN films grown on Si(100) by RF-MOMBE. Nanoscale Res Lett 2014, 9: 204. 10.1186/1556-276X-9-204View ArticleGoogle Scholar
- Butté R, Carlin JF, Feltin E, Gonschorek M, Nicolay S, Christmann G, Simeonov D, Castiglia A, Dorsaz J, Buehlmann HJ, Christopoulos S, Baldassarri Höger von Hög G, Grundy AJD, Mosca M, Pinquier C, Py MA, Demangeot F, Frandon J, Lagoudakis PG, Baumberg JJ, Grandjean N: Current status of AlInN layers lattice-matched to GaN for photonics and electronics. J Phys D Appl Phys 2007, 40: 6328–6344. 10.1088/0022-3727/40/20/S16View ArticleGoogle Scholar
- Mouti A, Rouviere JL, Cantoni M, Carlin JF, Feltin E, Grandjean N, Stadelmann P: Stress-modulated composition in the vicinity of dislocations in nearly lattice matched AlxIn1-x N/GaN heterostructures: a possible explanation of defect insensitivity. Phys Rev B 2011, 83: 195309.View ArticleGoogle Scholar
- Liu GY, Zhang J, Li XH, Huang GS, Paskova T, Evans KR, Zhao HP, Tansu N: Metalorganic vapor phase epitaxy and characterizations of nearly-lattice-matched AlInN alloys on GaN/sapphire templates and free-standing GaN substrates. J Cryst Growth 2012, 340: 66–73. 10.1016/j.jcrysgro.2011.12.037View ArticleGoogle Scholar
- Vennéguès P, Diaby BS, Kim-Chauveau H, Bodiou L, Schenk HPD, Frayssinet E, Martin RW, Watson IM: Nature and origin of V-defects present in metalorganic vapor phase epitaxy-grown (InxAl1-x) N layers as a function of InN content, layer thickness and growth parameters. J Cryst Growth 2012, 353: 108–114. 10.1016/j.jcrysgro.2012.05.004View ArticleGoogle Scholar
- Perillat-Merceroz G, Cosendey G, Carlin JF, Butté R, Grandjean N: Intrinsic degradation mechanism of nearly lattice-matched InAlN layers grown on GaN substrates. J Appl Phys 2013, 113: 063506. 10.1063/1.4790424View ArticleGoogle Scholar
- Potin V, Gil B, Charar S, Ruterana P, Nouet G: HREM study of basal stacking faults in GaN layers grown over sapphire substrate. Mat Sci Eng B Solid 2001, 82: 114–116. 10.1016/S0921-5107(00)00709-1View ArticleGoogle Scholar
- Schenk HPD, Nemoz M, Korytov M, Vennéguès P, Dräger AD, Hangleiter A: Indium incorporation dynamics into AIInN ternary alloys for laser structures lattice matched to GaN. Appl Phys Lett 2008, 93: 081116. 10.1063/1.2971027View ArticleGoogle Scholar
- Buβ ER, Rossow U, Bremers H, Hangleiter A: Lattice-matched AlInN in the initial stage of growth. Appl Phys Lett 2014, 104: 162104. 10.1063/1.4872226View ArticleGoogle Scholar
- Lin PY, Chen JY, Chen YC, Chang L: Effect of growth temperature on formation of amorphous nitride interlayer between AlN and Si(111). Jpn J Appl Phys 2013, 52: 08JB20. 10.7567/JJAP.52.08JB20View ArticleGoogle Scholar
- Darakchieva V, Beckers M, Xie MY, Hultman L, Monemar B, Carlin JF, Feltin E, Gonschorek M, Grandjean N: Effects of strain and composition on the lattice parameters and applicability of Vegard’s rule in Al-rich Al(1-x) In(x) N films grown on sapphire. J Appl Phys 2008, 103: 103513. 10.1063/1.2924426View ArticleGoogle Scholar
- Yakovlev EV, Lobanova AV, Talalaev RA, Watson IM, Lorenz K, Alves E: Mechanisms of AlInN growth by MOVPE: modeling and experimental study. Phys Status Solidi C 2008, 5: 1688–1690. 10.1002/pssc.200778588View ArticleGoogle Scholar
- Lorenz K, Franco N, Alves E, Pereira S, Watson IM, Martin RW, O’Donnell KP: Relaxation of compressively strained AlInN on GaN. J Cryst Growth 2008, 310: 4058–4064. 10.1016/j.jcrysgro.2008.07.006View ArticleGoogle Scholar
- Ichikawa J, Sakai Y, Chen ZT, Fujita K, Egawa T: Effect of growth temperature on structural quality of InAlN layer lattice matched to GaN grown by metal organic chemical vapor deposition. Jpn J Appl Phys 2012, 51: 01AF07. 10.7567/JJAP.51.01AF07View ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.