High-k gate stacks on low bandgap tensile strained Ge and GeSn alloys for field-effect transistors

Thumbnail Image
Full text at PDC
Publication Date
Advisors (or tutors)
Journal Title
Journal ISSN
Volume Title
Amer Chemical Soc.
Google Scholar
Research Projects
Organizational Units
Journal Issue
We present the epitaxial growth of Ge and Ge_(0.94)Sn_(0.06) layers with 1.4% and 0.4% tensile strain, respectively, by reduced pressure chemical vapor deposition on relaxed GeSn buffers and the formation of high-k/metal gate stacks thereon. Annealing experiments reveal that process temperatures are limited to 350°C to avoid Sn diffusion. Particular emphasis is placed on the electrical characterization of various high-k dielectrics, as 5nm Al_(2)O_(3), 5nm HfO_(2) or 1nm Al_(2)O_(3)/4nm HfO_(2), on strained Ge and strained Ge_(0.94)Sn_(0.06). Experimental capacitance-voltage characteristics are presented and the effect of the small bandgap, like strong response of minority carriers at applied field, are discussed via simulations.
© 2014 American Chemical Society. Este artículo está firmado por 14 autores. Authors thank to Valery Afanasiev, Catholic University of Leuven, for useful suggestions and discussions regarding Dit extraction. One of the authors, M.A Pampillon, thanks for funding by the FPI program (BES-2011-043798 and EEBB-I-13-07086) of the Spanish “Ministerio de Economía y Competitividad”. This work was partially supported by the German Federal Ministry of Education and Research under the project “Ultralow Power”.
Unesco subjects
1) Pillarisetty, R. Academic and Industry Research Progress in Germanium Nanodevices, Nature, 2011, 479, 324–328. (2) Dobbie, A., Myronov, M., Morris, R. J. H., Hassan, A. H. A., Prest, M. J.,; Shah, V. a., Parker, E. H. C., Whall, T. E., Leadley, D. R., Ultra-High Hole Mobility Exceeding One Million in a Strained Germanium Quantum Well, Appl. Phys. Lett., 2012, 101, 172108. (3) Zhao, M., Liang, R., Wang, J., Xu, J., Improved Electrical Properties of Ge Metal-Oxide-Semiconductor Devices with HfO2 Gate Dielectrics Using an Ultrathin GeSnOx Film as the Surface Passivation Layer, Appl. Phys. Lett., 2013, 102, 142906. (4) Gupta, S., Chen, R., Harris, J. S., Saraswat, K. C., Atomic Layer Deposition of Al2O3 on Germanium-Tin (GeSn) and Impact of Wet Chemical Surface Pre-Treatment, Appl. Phys. Lett., 2013, 103, 241601. (5) Hudait, M. K., Zhu, Y., Energy Band Alignment of Atomic Layer Deposited HfO2 Oxide Film on Epitaxial (100)Ge, (110)Ge, and (111)Ge Layers, J. Appl. Phys., 2013, 113, 114303. (6) Gusev, E. P., Shang, H., Copel, M., Gribelyuk, M., D’Emic, C., Kozlowski, P., Zabel, T., Microstructure and Thermal Stability of HfO[sub 2] Gate Dielectric Deposited on Ge(100), Appl. Phys. Lett., 2004, 85, 2334. (7) Yang, Y., Guo, P., Han, G., Lu Low, K., Zhan, C., Yeo, Y.-C., Simulation of Tunneling Field-Effect Transistors with Extended Source Structures, J. Appl. Phys., 2012, 111, 114514. (8) Kao, K.-H., Verhulst, A. S., Van de Put, M., Vandenberghe, W. G., Soree, B., Magnus, W., De Meyer, K., Tensile Strained Ge Tunnel Field-Effect Transistors: K · P Material Modeling and Numerical Device Simulation, J. Appl. Phys., 2014, 115, 044505. (9) Sánchez-Pérez, J. R., Boztug, C., Chen, F., Sudradjat, F. F., Paskiewicz, D. M., Jacobson, R. B., Lagally, M. G., Paiella, R., Direct-Bandgap Light-Emitting Germanium in Tensilely Strained Nanomembranes, Proc. Natl. Acad. Sci. U. S. A., 2011, 108, 18893–18898. (10) Gupta, S., Chen, R., Huang, Y., Kim, Y., Sánchez, E., Harris, J. S., Saraswat, K. C., Highly Selective Dry Etching of Germanium over Germanium-Tin (Ge1-xSnx): A Novel Route for Ge1-xSnx Nanostructure Fabrication, Nano Lett., 2013, 13, 3783–3790. (11) Wirths, S., Tiedemann, A. T., Ikonic, Z., Harrison, P., Holländer, B., Stoica, T., Mussler, G., Myronov, M., Hartmann, J. M., Grützmacher, D., Buca, D., Mantl, S., Band Engineering and Growth of Tensile Strained Ge/(Si)GeSn Heterostructures for Tunnel Field Effect Transistors, Appl. Phys. Lett., 2013, 102, 192103. (12) Kotlyar, R., Avci, U. E., Cea, S., Ríos, R., Linton, T. D., Kuhn, K. J., Young, I. A., Bandgap Engineering of Group IV Materials for Complementary N and P Tunneling Field Effect Transistors, Appl. Phys. Lett., 2013, 102, 113106. (13) Zhu, Y., Maurya, D., Priya, S., Hudait, M. K., Tensile-Strained Nanoscale Ge/In 0.16 Ga 0.84 As Heterostructure for Tunnel Field-E Ff Ect Transistor, ACS Appl. Mater. Interfaces, 2014, 6, 4947–4953. (14) Lu Low, K., Yang, Y., Han, G., Fan, W., Yeo, Y., Electronic Band Structure and Effective Mass Parameters of Ge1−xSnx Alloys, J. Appl. Phys., 2012, 112, 103715. (15) Wirths, S., Ikonic, Z., Tiedemann, A. T., Holländer, B., Stoica, T., Mussler, G., Breuer, U., Hartmann, J. M., Benedetti, A., Chiussi, S., Grützmacher, D., Mantl, S., Buca, D., Tensely Strained GeSn Alloys as Optical Gain Media, Appl. Phys. Lett., 2013, 103, 192110. (16) Vincent, B., Gencarelli, F., Bender, H., Merckling, C., Douhard, B., Petersen, D. H., Hansen, O., Henrichsen, H. H., Meersschaut, J., Vandervorst, W., Heyns, M., Loo, R., Caymax, M., Undoped and in-Situ B Doped GeSn Epitaxial Growth on Ge by Atmospheric Pressure-Chemical Vapor Deposition, Appl. Phys. Lett., 2011, 99, 152103. (17) D’Costa, V. R., Fang, Y. Y., Tolle, J., Kouvetakis, J., Menéndez, J., Ternary GeSiSn Alloys: New Opportunities for Strain and Band Gap Engineering Using Group-IV Semiconductors, Thin Solid Films, 2010, 518, 2531–2537. (18) Wirths, S., Buca, D., Ikonic, Z., Harrison, P., Tiedemann, A. T., Holländer, B., Stoica, T., Mussler, G., Breuer, U., Hartmann, J. M., Grützmacher, D., Mantl, S., SiGeSn Growth Studies Using Reduced Pressure Chemical Vapor Deposition towards Optoelectronic Applications, Thin Solid Films, 2013, 557, 183–187. (19) Bahder, T., Eight-Band KIp Model of Strained Zinc-Blende Crystals, Phys. Rev. B, 1990, 41, 11992–12001. (20) Gupta, S., Vincent, B., Yang, B., Lin, D., Gencarelli, F., Lin, J.-Y. J., Chen, R., Richard, O., Bender, H., Magyari-Kope, B., Caymax, M., Dekoster, J., Nishi, Y., Saraswat, K. C., Towards High Mobility GeSn Channel nMOSFETs: Improved Surface Passivation Using Novel Ozone Oxidation Method, In 2012 International Electron Devices Meeting, IEEE, 2012, pp. 16.2.1–16.2.4. (21) Wirths, S., Buca, D., Mussler, G., Tiedemann, A. T., Hollander, B., Bernardy, P., Stoica, T., Grutzmacher, D., Mantl, S., Reduced Pressure CVD Growth of Ge and Ge1-xSnx Alloys, ECS J. Solid State Sci. Technol., 2013, 2, N99–N102. (22) Baert, B., Schmeits, M., Nguyen, N. D., Study of the Energy Distribution of the Interface Trap Density in a GeSn MOS Structure by Numerical Simulation of the Electrical Characteristics, Appl. Surf. Sci., 2014, 291, 25–30. (23) Engel-Herbert, R., Hwang, Y., Stemmer, S., Comparison of Methods to Quantify Interface Trap Densities at dielectric/III-V Semiconductor Interfaces, J. Appl. Phys., 2010, 108, 124101. (24) Brammertz, G., Martens, K., Sioncke, S., Delabie, A., Caymax, M., Meuris, M., Heyns, M., Characteristic Trapping Lifetime and Capacitance-Voltage Measurements of GaAs Metal-Oxide-Semiconductor Structures, Appl. Phys. Lett., 2007, 91, 133510. (25) Electronic archive- New Semiconductor Materials. Characteristics and Properties (26) Nicollian, E.; Brews, J., MOS/metal Oxide Semiconductor/physics and Technology, (Wiley-Interscience: New York), 1982. (27) Deen, D. A., Champlain, J. G., High Frequency Capacitance-Voltage Technique for the Extraction of Interface Trap Density of the Heterojunction Capacitor: Terman’s Method Revised, Appl. Phys. Lett., 2011, 99, 053501. (28) Martens, K., Chui, C. O., Brammertz, G., De Jaeger, B., Kuzum, D., Meuris, M., Heyns, M., Krishnamohan, T., Saraswat, K., Maes, H. E., Groeseneken, G., On the Correct Extraction of Interface Trap Density of MOS Devices With High-Mobility Semiconductor Substrates, IEEE Trans. Electron Devices, 2008, 55, 547–556. (29) Schroder, D. K., Semiconductor Material and Device Characterizaion (Third Edit.), John Wiley & Sons , Inc., Hoboken, New Jersey, 2006. (30) Nguyen, N. D., Schmeits, M., Numerical Simulation of Impedance and Admittance of OLEDs, Phys. Status Solidi, 2006, 203, 1901–1914.