III-Nitride grating grown on freestanding HfO2 gratings
© Wang et al; licensee Springer. 2011
Received: 31 March 2011
Accepted: 18 August 2011
Published: 18 August 2011
We report here the epitaxial growth of III-nitride material on freestanding HfO2 gratings by molecular beam epitaxy. Freestanding HfO2 gratings are fabricated by combining film evaporation, electron beam lithography, and fast atom beam etching of an HfO2 film by a front-side silicon process. The 60-μm long HfO2 grating beam can sustain the stress change during the epitaxial growth of a III-nitride material. Grating structures locally change the growth condition and vary indium composition in the InGaN/GaN quantum wells and thus, the photoluminescence spectra of epitaxial III-nitride grating are tuned. Guided mode resonances are experimentally demonstrated in fabricated III-nitride gratings, opening the possibility to achieve the interaction between the excited light and the grating structure through guided mode resonance.
PACS: 78.55.Cr; 81.65.Cf; 81.15.Hi.
KeywordsInGaN/GaN QWs fast atom beam etching molecular beam epitaxy
Freestanding III-nitride structures can take advantage of the large refractive index contrast between III-nitride and air [1–7]. In such structure, the excited light has a potential to interact with freestanding structure through guided modes. Among the approaches towards creating suspended III-nitride structures, growth of III-nitride on freestanding structured template is an emerging technology. During growth process, nanoscale structures locally change the growth conditions and thus, the selective growth can be achieved to generate epitaxial III-nitride structures with smooth facets [8–11]. Meanwhile, freestanding III-nitride structures are formed by growth method and free of the etching damage. Moreover, the as-grown III-nitride structures can provide a natural optical cavity to support guided mode resonances, opening the possibility to achieve the interaction between the excited light and the epitaxial structures.
From the growth point of view, small material lattice mismatch between HfN and GaN crystals makes HfN film a superior buffer layer for the growth of GaN [12, 13]. During molecular beam epitaxy (MBE) growth, HfN surface can be formed by nitrifying HfO2 substrate. Hence, structured HfO2 film can be used as a template for growing III-nitride materials . On the other hand, HfO2 film is an excellent optical material with high laser damage threshold, thermal, and chemical stability [15–17]. Recently, we have fabricated freestanding HfO2 gratings and experimentally demonstrated their guided mode resonances . It is of great interest to implement the growth of III-nitride materials on freestanding HfO2 gratings.
Here, we demonstrate the freestanding III-nitride gratings grown on suspended HfO2 gratings. The epitaxial growth of InGaN/GaN quantum wells (QWs) are performed on freestanding HfO2 gratings by MBE technique. The optical performances of the resultant epitaxial structures are characterized in photoluminescence (PL) and reflectance measurements.
Experimental results and discussion
The epitaxial growth of III-nitride material is performed on the suspended HfO2 grating. The 60-μm long freestanding HfO2 grating beam can sustain the stress change during MBE growth. The PL spectra and reflectance of epitaxial III-nitride gratings are experimentally characterized. Epitaxial III-nitride grating can function as an optical cavity to support resonance mode, which is demonstrated and compared to the resonances of original HfO2 grating. These results indicate that resonant III-nitride gratings are promising for the development of resonant optical devices and the realization of the resonant emission. This work also opens the possibility for fabricating novel III-nitride optic devices by a combination of freestanding HfO2 nanostructures with epitaxial growth of III-nitride materials.
This work was partially supported by the JSPS Research Project (19106007 and P09070) and the NJUPT Research Project (NY211001).
- Rosenberg A, Carter M, Casey J, Kim M, Holm R, Henry R, Eddy C, Shamamian V, Bussmann K, Shi S, Prather D: Guided resonances in asymmetrical GaN photonic crystal slabs observed in the visible spectrum. Opt Express 2005, 13: 6564–6571. 10.1364/OPEX.13.006564View Article
- Choi HW, Hui KN, Lai PT, Chen P, Zhang XH, Tripathy S, Teng JH, Chua SJ: Lasing in GaN microdisks pivoted on Si. Appl Phys Lett 2006, 89: 211101. 10.1063/1.2392673View Article
- Meier C, Hennessy K, Haberer ED, Sharma R, Choi YS, McGroddy K, Keller S, DenBaars SP, Nakamura S, Hu EL: Visible resonant modes in GaN-based photonic crystal membrane cavities. Appl Phys Lett 2006, 88: 031111. 10.1063/1.2166680View Article
- Rosenberg A, Bussmann K, Kim M, Carter MW, Mastro MA, Holm RT, Henry RL, Caldwell JD, Eddy CR Jr: Fabrication of GaN suspended photonic crystal slabs and resonant nanocavities on Si(111). J Vac Sci Technol B 2007, 25(3):721. 10.1116/1.2723750View Article
- Arita M, Ishida S, Kako S, Iwamoto S, Arakawa Y: AlN air-bridge photonic crystal nanocavities demonstrating high quality factor. Appl Phys Lett 2007, 91: 051106. 10.1063/1.2757596View Article
- Cimalla V, Pezoldt J, Ambacher O: Group III nitride and SiC based MEMS and NEMS: materials properties, technology and applications. J Phys D: Appl Phys 2007, 40: 6386. 10.1088/0022-3727/40/20/S19View Article
- Matsubara H, Yoshimoto S, Saito H, Yue JL, Tanaka Y, Noda S: GaN Photonic-crystal surface-emitting laser at blue-violet wavelengths. Science 2008, 319: 445–447. 10.1126/science.1150413View Article
- Kikuchi A, Kawai M, Tada M, Kishino K: InGaN/GaN multiple quantum disk nanocolumn light-emitting diodes grown on (111) Si substrate. Jpn J Appl Phys 2004, 43: L1524. 10.1143/JJAP.43.L1524View Article
- Kishino K, Sekiguchi H, Kikuchi A: Improved Ti-mask selective-area growth (SAG) by rf-plasma-assisted molecular beam epitaxy demonstrating extremely uniform GaN nanocolumn arrays. J Cryst Growth 2009, 311: 2063–2068. 10.1016/j.jcrysgro.2008.11.056View Article
- Wang YJ, Hu FR, Hane K: Patterned growth of InGaN/GaN quantum wells on freestanding GaN grating by molecular beam epitaxy. Nanoscale Res Lett 2011, 6: 117. 10.1186/1556-276X-6-117View Article
- Wang YJ, Hu FR, Hane K: Lateral epitaxial overgrowth of GaN on patterned GaN-on-silicon substrate by molecular beam epitaxy. Semicond Sci Technol 2011, 26: 045015. 10.1088/0268-1242/26/4/045015View Article
- Armitage R, Yang Q, Feick H, Gebauer J, Weber ER, Shinkai S, Sasaki K: Lattice-matched HfN buffer layers for epitaxy of GaN on Si. Appl Phys Lett 2002, 81: 1450–1452. 10.1063/1.1501447View Article
- Xu X, Armitage R, Shinkai S, Sasaki K, Kisielowski C, Weber ER: Epitaxial condition and polarity in GaN grown on a HfN-buffered Si(111) wafer. Appl Phys Lett 2005, 86: 182104. 10.1063/1.1923192View Article
- Sameshima H, Wakui M, Hu FR, Hane K: A freestanding GaN/HfO 2 membrane grown by molecular beam epitaxy for GaN-Si hybrid MEMS. IEEE J Sel Top Quantum Electron 2009, 15: 1332–1337.View Article
- Priambodo PS, Maldonado TA, Magnusson R: Fabrication and characterization of high-quality waveguide-mode resonant optical filters. Appl Phys Lett 2003, 83: 3248. 10.1063/1.1618930View Article
- Wang Y, Lin Z, Cheng X, Xiao H, Zhang F, Zou S: Study of HfO2 thin films prepared by electron beam evaporation. Apple Surf Sci 228: 93.
- Chaganti K, Salakhutdinov I, Avrutsky I, Auner G, Mansfield J: Sub-micron grating fabrication on hafnium oxide thin-film waveguides with focused ion-beam milling. Opt Express 2006, 14: 1505. 10.1364/OE.14.001505View Article
- Wang YJ, Wu T, Kanamori Y, Hane K: Freestanding HfO 2 grating fabricated by fast atom beam etching. Nanoscale Res Lett 2011, 6: 367. 10.1186/1556-276X-6-367View Article
- Kuykendall T, Ulrich P, Aloni S, Yang PD: Complete composition tunability of InGaN nanowires using a combinatorial approach. Nat Mater 2007, 6: 951–956. 10.1038/nmat2037View Article
- Houdré R, Stanley RP, Ilegems M: Vacuum-field Rabi splitting in the presence of inhomogeneous broadening: resolution of a homogeneous line width in an inhomogeneously broadened system. Phys Rev A 1996, 53: 2711–2715. 10.1103/PhysRevA.53.2711View Article
- Andreani LC, Panzarini G, Kavokin AV, Vladimirova MR: Effect of inhomogeneous broadening on optical properties of excitons in quantum wells. Phys Rev B 1998, 57: 4670. 10.1103/PhysRevB.57.4670View Article
- Christmann G, Butteé R, Carlin J-F, Mosca M, Grandjean N, Feltin E: Room temperature polariton luminescence from a GaN/AlGaN quantum well microcavity. Appl Phys Lett 2006, 89: 071107. 10.1063/1.2335404View Article
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