Although conventional homoepitaxy forms high-quality epitaxial layers1,2,3,4,5, the limited set of material systems for commercially available wafers restricts the range of materials that can be grown homoepitaxially. At the same time, conventional heteroepitaxy of lattice-mismatched systems produces dislocations above a critical strain energy to release the accumulated strain energy as the film thickness increases. The formation of dislocations, which severely degrade electronic/photonic device performances6,7,8, is fundamentally unavoidable in highly lattice-mismatched epitaxy9,10,11. Here, we introduce a unique mechanism of relaxing misfit strain in heteroepitaxial films that can enable effective lattice engineering. We have observed that heteroepitaxy on graphene-coated substrates allows for spontaneous relaxation of misfit strain owing to the slippery graphene surface while achieving single-crystalline films by reading the atomic potential from the substrate. This spontaneous relaxation technique could transform the monolithic integration of largely lattice-mismatched systems by covering a wide range of the misfit spectrum to enhance and broaden the functionality of semiconductor devices for advanced electronics and photonics.
Subscribe to Journal
Get full journal access for 1 year
only $15.58 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data that support the findings of this study are available from the corresponding author upon reasonable request.
Chen, C. Q. et al. GaN homoepitaxy on freestanding (1100) oriented GaN substrates. Appl. Phys. Lett. 81, 3194–3196 (2002).
Kwon, O. et al. Monolithic integration of AlGaInP laser diodes on SiGe/Si substrates by molecular beam epitaxy. J. Appl. Phys. 100, 13103 (2006).
Matsunami, H. & Kimoto, T. Step-controlled epitaxial growth of SiC: high quality homoepitaxy. Mater. Sci. Eng. R. Rep. 20, 125–166 (1997).
Vaisman, M. et al. Effects of growth temperature and device structure on GaP solar cells grown by molecular beam epitaxy. Appl. Phys. Lett. 106, 063903 (2015).
Voigtländer, B., Weber, T., Šmilauer, P. & Wolf, D. E. Transition from island growth to step-flow growth for Si/Si (100) epitaxy. Phys. Rev. Lett. 78, 2164–2167 (1997).
Luan, H.-C. et al. High-quality Ge epilayers on Si with low threading-dislocation densities. Appl. Phys. Lett. 75, 2909–2911 (1999).
Currie, M. T., Samavedam, S. B., Langdo, T. A., Leitz, C. W. & Fitzgerald, E. A. Controlling threading dislocation densities in Ge on Si using graded SiGe layers and chemical-mechanical polishing. Appl. Phys. Lett. 72, 1718–1720 (1998).
Andre, C. L. et al. Impact of dislocation densities on n+∕ p and p+∕ n junction GaAs diodes and solar cells on SiGe virtual substrates. J. Appl. Phys. 98, 14502 (2005).
Lee, M. L., Antoniadis, D. A. & Fitzgerald, E. A. Challenges in epitaxial growth of SiGe buffers on Si (111), (110), and (112). Thin Solid Films 508, 136–139 (2006).
Chen, R. et al. Nanolasers grown on silicon. Nat. Photonics 5, 170–175 (2011).
Ebert, C. B., Eyres, L. A., Fejer, M. M. & Harris, J. S. Jr MBE growth of antiphase GaAs films using GaAs/Ge/GaAs heteroepitaxy. J. Cryst. Growth 201-202, 187–193 (1999).
Lee, M. L., Fitzgerald, E. A., Bulsara, M. T., Currie, M. T. & Lochtefeld, A. Strained Si, SiGe, and Ge channels for high-mobility metal-oxide-semiconductor field-effect transistors. J. Appl. Phys. 97, 1 (2005).
Bean, J. C., Sheng, T. T., Feldman, L. C., Fiory, A. T. & Lynch, R. T. Pseudomorphic growth of GexSi1−x on silicon by molecular beam epitaxy. Appl. Phys. Lett. 44, 102–104 (1984).
Fitzgerald, E. A. et al. Totally relaxed GexSi1−x layers with low threading dislocation densities grown on Si substrates. Appl. Phys. Lett. 59, 811–813 (1991).
Song, T. L., Chua, S. J., Fitzgerald, E. A., Chen, P. & Tripathy, S. Strain relaxation in graded InGaN/GaN epilayers grown on sapphire. Appl. Phys. Lett. 83, 1545–1547 (2003).
Massies, J. & Grandjean, N. Oscillation of the lattice relaxation in layer-by-layer epitaxial growth of highly strained materials. Phys. Rev. Lett. 71, 1411–1414 (1993).
Daruka, I. & Barabási, A.-L. Dislocation-free island formation in heteroepitaxial growth: a study at equilibrium. Phys. Rev. Lett. 79, 3708–3711 (1997).
Kim, Y. et al. Remote epitaxy through graphene enables two-dimensional material-based layer transfer. Nature 544, 340–343 (2017).
Kong, W. et al. Polarity governs atomic interaction through two-dimensional materials. Nat. Mater. 17, 999–1004 (2018).
Li, X. et al. Large-area two-dimensional layered hexagonal boron nitride grown on sapphire by metalorganic vapor phase epitaxy. Cryst. Growth Des. 16, 3409–3415 (2016).
Attolini, G. et al. Optical and structural characterization of LP MOVPE grown lattice matched InGaP/GaAs heterostructures. Mater. Sci. Eng. B 91-92, 123–127 (2002).
Kato, T., Matsumoto, T. & Ishida, T. Raman spectral behavior of In1-xGaxP (0 < x < 1). Jpn. J. Appl. Phys. 27, 983–986 (1988).
Lee, H. et al. Study of strain and disorder of InxGa1−xP/(GaAs, graded GaP)(0.25 ≤ x ≤ 0.8) using spectroscopic ellipsometry and Raman spectroscopy. J. Appl. Phys. 75, 5040–5051 (1994).
King-Ning, T., Mayer, J. W. & Feldman, L. C. Electronic Thin Film Science for Electrical Engineers and Materials Scientists (Macmillan, 1996).
Matthews, J. W. & Blakeslee, A. E. Defects in epitaxial multilayers: I. Misfit dislocations. J. Cryst. Growth 27, 118–125 (1974).
Freundlich, A., Bensaoula, A., Bensaoula, A. H. & Rossignol, V. Interface and relaxation properties of chemical beam epitaxy grown GaP/GaAs structures. J. Vac. Sci. Technol. B 11, 843–846 (1993).
Morales, F. M. et al. Microstructural improvements of InP on GaAs (001) grown by molecular beam epitaxy by in situ hydrogenation and postgrowth annealing. Appl. Phys. Lett. 94, 41919 (2009).
Bae, S.-H. et al. Unveiling the carrier transport mechanism in epitaxial graphene for forming wafer-scale, single-domain graphene. Proc. Natl Acad. Sci. USA 114, 4082–4086 (2017).
Shim, J. et al. Controlled crack propagation for atomic precision handling of wafer-scale two-dimensional materials. Science 362, 665–670 (2018).
Kim, J. et al. Layer-resolved graphene transfer via engineered strain layers. Science 342, 833–836 (2013).
Bae, S.-H. et al. Integration of bulk materials with two-dimensional materials for physical coupling and applications. Nat. Mater. 18, 550–560 (2019).
Kum, H. et al. Epitaxial growth and layer-transfer techniques for heterogeneous integration of materials for electronic and photonic devices. Nat. Electron. 2, 439–450 (2019).
Han, Y. et al. Sub-nanometre channels embedded in two-dimensional materials. Nat. Mater. 17, 129–133 (2018).
Hÿtch, M. J., Snoeck, E. & Kilaas, R. Quantitative measurement of displacement and strain fields from HREM micrographs. Ultramicroscopy 74, 131–146 (1998).
This work is supported by the Defense Advanced Research Projects Agency Young Faculty Award (award no. 029584-00001), the Department of Energy Solar Energy Technologies Office (award no. DE-EE0008558), the Air Force Research Laboratory (award no. FA9453-18-2-0017), ROHM Co., and LG electronics. Y.H. and D.M. were supported by the National Science Foundation Division of Material Research (award no. 1719875). We are grateful for general support from J.S. Lee (Head of the Materials and Devices Advanced Research Institute, LG Electronics).
The authors declare no competing interests.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Raman data, % relaxation data.
Lattice constant of InGaP on bare GaAs substrates along the x-axis and lattice constant of InGaP on graphene-coated GaAs substrates along the y-axis.
Energy barrier required for the interface sliding of epilayers on graphene/substrates and bare substrates, threshold energy for each situation and critical thickness of the heteroepitaxy film.
HRXRD azimuthal off-axis φ scan of the GaP epilayer.
About this article
Cite this article
Bae, S., Lu, K., Han, Y. et al. Graphene-assisted spontaneous relaxation towards dislocation-free heteroepitaxy. Nat. Nanotechnol. (2020). https://doi.org/10.1038/s41565-020-0633-5