Published 4 issues per year
ISSN Print: 2152-2057
ISSN Online: 2152-2073
Indexed in
COHERENT TO SEMI-COHERENT TRANSITION IN SEMICONDUCTOR HETEROEPITAXIAL SUPERLATTICES
ABSTRACT
The degradation in the performance of devices based on semiconductor epitaxial systems depends on the state of residual stress. In the case of growth of a homogeneous epitaxial film on a substrate, the build-up of coherency stresses drives the formation of interfacial misfit dislocations. In systems with a 'reasonably high' magnitude of misfit, this occurs beyond a critical thickness (hc) of the film; wherein the strain energy of the system is minimized by formation of misfit dislocations at the film-substrate interface. The current work pertains to the coherent to semi-coherent transition of epitaxial superlattices. Using AlN/Al03Ga07N superlattices on GaN substrate as a model system, finite element simulations are used to study the effect of the periodicity of the superlattice (hSL) and configurations of periodic layers on the critical thickness (hc). Due to the presence of multiple interfaces in a superlattice structure, the most favorable interface for the formation of interfacial misfit dislocation is also determined. Finite element simulations were carried out, taking into account the parameters such as number of periods (n), the total thickness of the overlayer (n.hSL), and the order of AlN & AlGaN layers over the GaN substrate. The salient observations are as follows: (i) the hc (n.hSL) of the superlattice is independent of the periodicity factor 'n' and configurations of periodic layers in a superlattice, (ii) Al03Ga07N layer has a buffer effect on the stress state of superlattice and critical thickness, and (iii) the interface between the substrate and first layer of a superlattice is the most probable position for the formation of misfit edge dislocation.
Figures
-
Barghout, K. and Chaudhuri, J., Calculation of Residual Thermal Stress in GaN Epitaxial Layers Grown on Technologically Important Substrates, Mater. Sci., vol. 39, no.18, pp. 5817-5823, 2004.
-
Chen, D., Ma, X.L., and Wang, Y.M., Thickness-Dependent Structural Transformation in the AlN Film, ActaMaterialia, vol. 53, no. 19, pp.5223-5227, 2005.
-
Fitzgerald, E.A., Ast, D.G., Kirchner, P.D., Pettit, G.D., and Woodall, J.M., Structure and Recombination in InGaAs/GaAs Heterostructures, J. Appl. Phys., vol. 63, no. 3, pp. 693-703, 1988.
-
Floro, J.A., Follstaedt, D.M., Provencio, P., Hearne, S.J., and Lee, S.R., Misfit Dislocation Formation in the AlGaNGaN Heterointerface, J. Appl. Phys., vol. 96, no. 12, pp. 7087-7094, 2004.
-
Freund, L.B. and Suresh, S., Thin Film Materials: Stress, Defect Formation and Surface Evolution, Cambridge, UK: Cambridge University Press, 2003.
-
He, C., Qin, Z., Xu, F., Zhang, L., Wang, J., Hou, M., Zhang, S., Wang, X., Ge, W., and Shen, B., Mechanism of Stress-Driven Composition Evolution During Hetero-Epitaxy in a Ternary AlGaN System, Sci. Rep, vol. 6, no. 1, pp. 25124,2016.
-
Herbeaux, C., Di Persio, J., and Lefebvre, A., Misfit Dislocations in In0.15Ga0.85As/GaAs Strained-Layer Superlattices, Appl. Phys. Lett, vol. 54, no. 11, pp. 1004-1006,1989.
-
Hull, R., Bean, J.C., Werder, D.J. and Leibenguth, R.E., In Situ Observations of Misfit Dislocation Propagation in GexSi1-x/Si(100) Heterostructures, Appl. Phys. Lett, vol. 52, no. 19, 1605-1607, 1988.
-
Jain, S.C., Willis, J.R., and Bullough, R., A Review of Theoretical and Experimental Work on the Structure of Ge x Si1-x Strained Layers and Superlattices, with Extensive Bibliography, Adv. Phys., vol. 39, no. 2, pp. 127-190, 1990.
-
Kasper, E. and Herzog, H.J., Elastic Strain and Misfit Dislocation Density in Si0.92Ge0.08 Films on Silicon Substrates, Thin Solid Films, vol. 44, no. 3, pp. 357-370, 1977.
-
Kasper, E., Herzog, H.J., Da Mbkes, H., and Abstreiter, G., Layered Structure and Epitaxy, Materials Research Society Symposium Proceedings, J.M. Gibson, G.C. Osbourn, and R.M. Tromp, Eds., Pittsburgh, PA: Materials Research Society, vol. 56, pp. 347-357, 1986.
-
Kim, I.W., Li, Quan., Marks, L.D., and Barnett, S.A., Critical Thickness for Transformation of Epitaxially Stabilized Cubic AlN in Superlattices, Appl. Phys. Lett., vol. 78, no. 7, pp. 892-894, 2001.
-
LeGoues, F.K., Meyerson, B.S., and Morar, J.F., Anomalous Strain Relaxation in SiGe Thin Films and Superlattices, Phys. Rev. Lett, vol. 66, no. 22, pp. 2903-2906, 1991.
-
Olsen, G.H. and Ettenberg, M., Calculated Stresses in Multilayered Heteroepitaxial Structures, J. Appl. Phys, vol. 48, no. 6, pp. 2543-2547, 1977.
-
People, R., Physics and Applications of GexSil-x/Si Strained-Layer Heterostructures, IEEE J. Quant. Electron, vol. 22, no. 9, pp. 1696-1710, 1986.
-
Sipatov, A.Yu., Misfit Dislocation Superlattices in IV-VI Multilayered Compounds as Zero Dimensional Quantum Boxes, Low Temp. Phys., vol. 25, no. 5, pp. 376-378, 1999.
-
Smith, A.M., Mohs, A.M., and Nie, S., Tuning the Optical and Electronic Properties of Colloidal Nanocrystals by Lattice Strain, Nat. Nanotechnol., vol. 4, no. 1, pp. 56-63, 2009.
-
Soderberg, H., Oden, M., Molina, J.M., and Hultman, L., Nanostructure Formation During Deposition of TiNSiN Nanomultilayer Films by Reactive Dual Magnetron Sputtering, J. Appl. Phys., vol. 97, no. 11, pp. 114327-114331, 2005.
-
Su, J., Armour, E.A., Krishnan, B., Lee, S.M., and Papasouliotis, G.D., Stress Engineering with AlN/GaN Superlattices for Epitaxial GaN on 200 mm Silicon Substrates using a Single Wafer Rotating Disk MOCVD Reactor, J. Mater. Res, vol. 30, pp. 2846-2858, 2015.
-
Subramaniam, A. and Kumar, A., Simulations of Dislocations and Coherent Nanostructures, in Computational Finite Element Methods in Nanotechnology, S.M. Musa, Ed., Boca Raton, FL: CRC Press, pp. 149-184, 2013.
-
Vdovin, V.I., Misfit Dislocations in Epitaxial Heterostructures: Mechanisms of Generation and Multiplication, Phys. Stat. Sol. (A), vol. 171, no. 1, pp. 239-250, 1999.
-
Vdovin, V.I., Mil'vidskii, M.G., Yugova, T.G., Lyutovich, K.L., and Saidov, S.M., Effect of Alloy Composition on Defect Formation in GexSil-x/Si Heterostructures Obtained by Molecular Beam Epitaxy, Cryst. Growth, vol. 141, nos. 1-2, pp. 109-118, 1994.
-
Vdovin, V.I., Mil'vidskii, M.G., and Yugova, T.G., Peculiarities of Defect Formation in SiGe/Si and SiGe/ Ge Heterostructures, Solid State Phenom., vol. 345, pp. 345-352, 1993.
-
Zhao, J., Guo, H., He, X., Zhang, Q., Gu, L., Li, X., Jin, K., Yang, T., Ge, C., Luo, Y., He, M., Long, Y., Wang, J., Qian, H., Wang, C., Lu, H., Yang, G., and Ibrahim, K., Manipulating the Structural and Electronic Properties of Epitaxial SrCoO2.5 Thin Films by Tuning the Epitaxial Strain, ACS Appl. Mater. Interfaces, vol. 10, p. 10211, 2018.
-
Zou, J., Cockayne, D.J.H., and Usher, B.F., Misfit Dislocations and Critical Thickness in InGaAs/GaAs Heterostructure Systems, J. Appl. Phys, vol. 73, no. 2, pp. 619-626, 1993.