當傳統矽基材料電晶體微縮達到物理極限，為因應未來5奈米以下通道電晶體，尋找替代材料來替代矽基電晶體變得極為重要。對於這樣的微縮電晶體，短通道效應將會嚴重影元件性能和操作。為了降低短通道的影響，在極小尺度下，二維材料比矽有更多優勢。自從石墨稀被成功分離製備後，為二維材料的研究注入許多動能，其中，過渡性金屬硫屬化合物因為獨特的光與電特性受到許多關注，當中以二硫化鉬(MoS2)因為應用範圍廣大和相對較高的電子等效質量，被認為具有很大潛能，能夠替代傳統半導體。
本研究受到清大材料所李奕賢教授實驗室幫助下，成功以使用化學氣相沉積方式製備的高品質和大面積單層二硫化鉬，製作出具高效能單層二硫化鉬電晶體。該電晶體為一平面背閘極結構，採用通道先製的方式製作，通道長寬為奈米等級。閘極氧化層為10奈米二氧化鉿，以原子層化學氣相沉積系統沉積。再者，使用電子束微影系統製作黏附層，以增強接觸電極金的附著力。其後轉移材料，使用電子束微影系統製作第二道光罩，以乾式蝕刻定義通道寬度和完成元件隔離。隨後第三道光罩定義通道長度，使用掀離製程完成接觸電極。接觸電極採用金因為其在環境有良好的穩定性。
本篇研究中,所有電性量測皆在大氣中進行。所製備出來的電晶體具有高輸出電流，最高可達到111(μA/μm)和高載子遷移率81(cm2/Vs)，與文獻中以剝離方式或是化學氣相沉積製備的單層二硫化鉬電晶體相比,皆是可以匹敵的。許多提升元件特性方法也在本文中討論，諸如熱退火製程，High k材料應用，另外，載子速度飽和現象，通道調變效應也有在本文中闡明。再者，藉由TLM圖案展示萃取接觸阻抗的方法，經由減去接觸阻抗的影響後，觀察到載子遷移率大幅上升，揭露元件的真實電性。本篇論文旨在製備與改善單層二硫化鉬電晶體特性，為未來相關實驗提供有效的分析工具及方法。

As conventional silicon based transistors approach its scaling limit, searching for the alternative channel material is urgently needed for future sub 5 nanometer gate length devices. For such ultimately scaled transistors, short channel effects become dominant and severely impede electronic device operation. In this regard, to suppress short channel effects, two dimensional (2D) material shows strong potential compared to silicon. Since graphene were prepared successfully in 2004, this breakthrough have inspired many researches on 2D materials. Among various 2D materials, transition metal dichalcogenides (TMDs) have attracted much attention due to its unique optical and electrical properties. Molybdenum disulfide (MoS2), a member of TMDs family, is versatile and have large effective mass, considered to be one of promising candidates for future electronic devices.
In this thesis, high-performance monolayer MoS2 nanosheet transistors have been successfully fabricated. The monolayer MoS2 is grown by chemical vapor deposition, transferred and provided by NTHU Prof. Yi-Hsien Lee’s group. The monolayer MoS2 transistors are in back-gate geometry following channel first fabrication. The devices channel lengths are ranging from 100 nm to 400nm, while channel widths vary from 50nm to 400nm. The gate dielectric is High k HfO2 with thickness 10nm approximately, deposited by atomic layer deposition at 250 degrees. Adhesion layer is defined by electron beam lithography to enhance the metal contact (Au) adhesion. Afterwards, two further electron beam lithography masks were performed for channel width and channel length formation. Channel width is accomplished by dry etching, achieving device formation. Channel length is completed by lift-off process after metal contact (Au) deposited by electron beam evaporation, realizing S/D region. Au is chosen for its stability in ambient.
In this thesis, all electrical measurements were carried out in ambient conditions. The fabricated transistor perform high ON current of 111 μA/μm and intrinsic field effect mobility of 81cm2/Vs without noticeable short channel effect. Without contact optimization, our device are comparable or superior compared with other MoS2 transistors in literature, indicating the high quality of monolayer MoS2 and validity of the fabrication process. Considerable strategies for improving device performance, such as annealing, high k boosting are discussed. In addition, velocity saturation and transistor scaling behavior are also observed and discussed in this work. Moreover, the extraction of contact resistance by TLM pattern are also demonstrated. After subtracting the effect from contact resistance, significant enhancement on mobility are confirmed, uncovering the real device performance.
This work provide a practical route to improve the performance of monolayer MoS2 transistor and useful electrical characterization method.

[1] P. K. Bondyopadhyay, "Moore's law governs the silicon revolution," Proc. IEEE, vol. 86, no. 1, pp. 78-81, 1998.
[2] W. Jing and M. Lundstrom, "Does source-to-drain tunneling limit the ultimate scaling of MOSFETs?," in Digest. International Electron Devices Meeting, 2002, pp. 707-710.
[3] J. P. Colinge, Multiple-gate SOI MOSFETs. 2007, pp. 2071-2076.
[4] K. S. Novoselov et al., "Electric Field Effect in Atomically Thin Carbon Films," Science, 10.1126/science.1102896 vol. 306, no. 5696, p. 666, 2004.
[5] S. Z. Butler et al., "Progress, Challenges, and Opportunities in Two-Dimensional Materials Beyond Graphene," ACS Nano, vol. 7, no. 4, pp. 2898-2926, 2013/04/23 2013.
[6] P. Yadav, P. K. Srivastava, and S. Ghosh, "High field effect mobility of 10,000 cm2/V-s and 5,000 cm2/V-s in undoped and doped monolayer graphene-based transistors," in 2014 IEEE 2nd International Conference on Emerging Electronics (ICEE), 2014, pp. 1-3.
[7] R. R. Nair et al., "Fine Structure Constant Defines Visual Transparency of Graphene," Science, 10.1126/science.1156965 vol. 320, no. 5881, p. 1308, 2008.
[8] S. Ghosh et al., "Extremely high thermal conductivity of graphene: Prospects for thermal management applications in nanoelectronic circuits," Appl. Phys. Lett., vol. 92, no. 15, p. 151911, 2008/04/14 2008.
[9] F. Schwierz, "Graphene transistors," Nature Nanotechnology, Review Article vol. 5, p. 487, 05/30/online 2010.
[10] K. Shavanova et al., "Application of 2D Non-Graphene Materials and 2D Oxide Nanostructures for Biosensing Technology," Sensors, vol. 16, no. 2, 2016.
[11] K. F. Mak, C. Lee, J. Hone, J. Shan, and T. F. Heinz, "Atomically Thin MoS2: A New Direct-Gap Semiconductor," Phys. Rev. Lett., vol. 105, no. 13, p. 136805, 09/24/ 2010.
[12] K. S. Novoselov et al., "Two-dimensional atomic crystals," Proc. Natl. Acad. Sci. U.S.A., 10.1073/pnas.0502848102 vol. 102, no. 30, p. 10451, 2005.
[13] R. S. Sundaram et al., "Electroluminescence in Single Layer MoS2," Nano Lett., vol. 13, no. 4, pp. 1416-1421, 2013/04/10 2013.
[14] S. Bertolazzi, J. Brivio, and A. Kis, "Stretching and Breaking of Ultrathin MoS2," ACS Nano, vol. 5, no. 12, pp. 9703-9709, 2011/12/27 2011.
[15] B. Liu, J. Yang, C. Liu, T. Hu, Y. Han, and C. Gao, "The ground electronic state of TiS2: experimental and theoretical studies," physica status solidi c, vol. 8, no. 5, pp. 1683-1686, 2011/05/01 2011.
[16] A. Kuc, N. Zibouche, and T. Heine, "Influence of quantum confinement on the electronic structure of the transition metal sulfide TS2," Physical Review B, vol. 83, no. 24, p. 245213, 06/30/ 2011.
[17] K. K. Kam and B. A. Parkinson, "Detailed photocurrent spectroscopy of the semiconducting group VIB transition metal dichalcogenides," The Journal of Physical Chemistry, vol. 86, no. 4, pp. 463-467, 1982/02/01 1982.
[18] H. Qiu et al., "Hopping transport through defect-induced localized states in molybdenum disulphide," Nature Communications, Article vol. 4, p. 2642, 10/23/online 2013.
[19] B. Radisavljevic and A. Kis, "Mobility engineering and a metal–insulator transition in monolayer MoS2," Nature Materials, Article vol. 12, p. 815, 06/23/online 2013.
[20] S. Thiele, W. Kinberger, R. Granzner, G. Fiori, and F. Schwierz, "The prospects of two-dimensional materials for ultimately scaled CMOS," in 2017 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon (EUROSOI-ULIS), 2017, pp. 113-116.
[21] B. Radisavljevic, A. Radenovic, J. Brivio, V. Giacometti, and A. Kis, "Single-layer MoS2 transistors," Nat. Nanotechnol., vol. 6, p. 147, 01/30/online 2011.
[22] Q. H. Wang, K. Kalantar-Zadeh, A. Kis, J. N. Coleman, and M. S. Strano, "Electronics and optoelectronics of two-dimensional transition metal dichalcogenides," Nature Nanotechnology, Review Article vol. 7, p. 699, 11/06/online 2012.
[23] A. Splendiani et al., "Emerging Photoluminescence in Monolayer MoS2," Nano Lett., vol. 10, no. 4, pp. 1271-1275, 2010/04/14 2010.
[24] L. Li et al., "Black phosphorus field-effect transistors," Nature Nanotechnology, Article vol. 9, p. 372, 03/02/online 2014.
[25] F. Bonaccorso, A. Lombardo, T. Hasan, Z. Sun, L. Colombo, and A. C. Ferrari, "Production and processing of graphene and 2d crystals," Mater. Today, vol. 15, no. 12, pp. 564-589, 2012/12/01/ 2012.
[26] K. S. Novoselov and A. H. C. Neto, "Two-dimensional crystals-based heterostructures: materials with tailored properties," Phys. Scr., vol. 2012, no. T146, p. 014006, 2012.
[27] J. Smith Ronan et al., "Large-Scale Exfoliation of Inorganic Layered Compounds in Aqueous Surfactant Solutions," Adv. Mater., vol. 23, no. 34, pp. 3944-3948, 2011/09/08 2011.
[28] G. Eda, H. Yamaguchi, D. Voiry, T. Fujita, M. Chen, and M. Chhowalla, "Photoluminescence from Chemically Exfoliated MoS2," Nano Lett., vol. 11, no. 12, pp. 5111-5116, 2011/12/14 2011.
[29] M. A. Bissett, S. D. Worrall, I. A. Kinloch, and R. A. W. Dryfe, "Comparison of Two-Dimensional Transition Metal Dichalcogenides for Electrochemical Supercapacitors," Electrochim. Acta, vol. 201, pp. 30-37, 2016/05/20/ 2016.
[30] X. Li et al., "Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils," Science, 10.1126/science.1171245 vol. 324, no. 5932, p. 1312, 2009.
[31] Y. Zhan, Z. Liu, S. Najmaei, M. Ajayan Pulickel, and J. Lou, "Large-Area Vapor-Phase Growth and Characterization of MoS2 Atomic Layers on a SiO2 Substrate," Small, vol. 8, no. 7, pp. 966-971, 2012/04/10 2012.
[32] Y. H. Lee et al., "Synthesis of large-area MoS2 atomic layers with chemical vapor deposition," Adv. Mater., vol. 24, no. 17, pp. 2320-5, May 2 2012.
[33] K.-K. Liu et al., "Growth of Large-Area and Highly Crystalline MoS2 Thin Layers on Insulating Substrates," Nano Lett., vol. 12, no. 3, pp. 1538-1544, 2012/03/14 2012.
[34] J. Jeon et al., "Layer-controlled CVD growth of large-area two-dimensional MoS2 films," Nanoscale, 10.1039/C4NR04532G vol. 7, no. 5, pp. 1688-1695, 2015.
[35] X. Ling et al., "Role of the Seeding Promoter in MoS2 Growth by Chemical Vapor Deposition," Nano Lett., vol. 14, no. 2, pp. 464-472, 2014/02/12 2014.
[36] H. Wang et al., "Large-scale 2D electronics based on single-layer MoS2 grown by chemical vapor deposition," in 2012 International Electron Devices Meeting, 2012, pp. 4.6.1-4.6.4.
[37] L. Yu et al., "Enhancement-mode single-layer CVD MoS2 FET technology for digital electronics," in 2015 IEEE International Electron Devices Meeting (IEDM), 2015, pp. 32.3.1-32.3.4.
[38] H. Fang, S. Chuang, T. C. Chang, K. Takei, T. Takahashi, and A. Javey, "High-Performance Single Layered WSe2 p-FETs with Chemically Doped Contacts," Nano Lett., vol. 12, no. 7, pp. 3788-3792, 2012/07/11 2012.
[39] O. Lopez-Sanchez, D. Lembke, M. Kayci, A. Radenovic, and A. Kis, "Ultrasensitive photodetectors based on monolayer MoS2," Nature Nanotechnology, vol. 8, p. 497, 06/09/online 2013.
[40] M. Bernardi, M. Palummo, and J. C. Grossman, "Extraordinary Sunlight Absorption and One Nanometer Thick Photovoltaics Using Two-Dimensional Monolayer Materials," Nano Lett., vol. 13, no. 8, pp. 3664-3670, 2013/08/14 2013.
[41] F. Withers et al., "Light-emitting diodes by band-structure engineering in van der Waals heterostructures," Nature Materials, vol. 14, p. 301, 02/02/online 2015.
[42] G.-H. Lee et al., "Flexible and Transparent MoS2 Field-Effect Transistors on Hexagonal Boron Nitride-Graphene Heterostructures," ACS Nano, vol. 7, no. 9, pp. 7931-7936, 2013/09/24 2013.
[43] S. Kim et al., "High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals," Nature Communications, Article vol. 3, p. 1011, 08/21/online 2012.
[44] D. Sarkar, W. Liu, X. Xie, A. C. Anselmo, S. Mitragotri, and K. Banerjee, "MoS2 Field-Effect Transistor for Next-Generation Label-Free Biosensors," ACS Nano, vol. 8, no. 4, pp. 3992-4003, 2014/04/22 2014.
[45] Q. He et al., "Fabrication of Flexible MoS2 Thin-Film Transistor Arrays for Practical Gas-Sensing Applications," Small, vol. 8, no. 19, pp. 2994-2999, 2012/10/08 2012.
[46] F. K. Perkins, A. L. Friedman, E. Cobas, P. M. Campbell, G. G. Jernigan, and B. T. Jonker, "Chemical Vapor Sensing with Monolayer MoS2," Nano Lett., vol. 13, no. 2, pp. 668-673, 2013/02/13 2013.
[47] E. Zhang et al., "Tunable Charge-Trap Memory Based on Few-Layer MoS2," ACS Nano, vol. 9, no. 1, pp. 612-619, 2015/01/27 2015.
[48] R. Chau et al., "A 50 nm depleted-substrate CMOS transistor (DST)," in International Electron Devices Meeting. Technical Digest (Cat. No.01CH37224), 2001, pp. 29.1.1-29.1.4.
[49] M. Luisier, M. Lundstrom, D. A. Antoniadis, and J. Bokor, "Ultimate device scaling: Intrinsic performance comparisons of carbon-based, InGaAs, and Si field-effect transistors for 5 nm gate length," in 2011 International Electron Devices Meeting, 2011, pp. 11.2.1-11.2.4.
[50] S. Das, H.-Y. Chen, A. V. Penumatcha, and J. Appenzeller, "High Performance Multilayer MoS2 Transistors with Scandium Contacts," Nano Lett., vol. 13, no. 1, pp. 100-105, 2013/01/09 2013.
[51] H. Liu and P. D. Ye, "MoS2 Dual-Gate MOSFET With Atomic-Layer-Deposited Al2O3 as Top-Gate Dielectric," IEEE Electron Device Letters, vol. 33, no. 4, pp. 546-548, 2012.
[52] M. Schmidt, M. C. Lemme, H. D. B. Gottlob, F. Driussi, L. Selmi, and H. Kurz, "Mobility extraction in SOI MOSFETs with sub 1nm body thickness," Solid·State Electron., vol. 53, no. 12, pp. 1246-1251, 2009/12/01/ 2009.
[53] W. Liu et al., "High-performance few-layer-MoS2 field-effect-transistor with record low contact-resistance," in 2013 IEEE International Electron Devices Meeting, 2013, pp. 19.4.1-19.4.4.
[54] H. Liu et al., "Switching Mechanism in Single-Layer Molybdenum Disulfide Transistors: An Insight into Current Flow across Schottky Barriers," ACS Nano, vol. 8, no. 1, pp. 1031-1038, 2014/01/28 2014.
[55] D. Liu, Y. Guo, L. Fang, and J. Robertson, "Sulfur vacancies in monolayer MoS2 and its electrical contacts," Appl. Phys. Lett., vol. 103, no. 18, p. 183113, 2013/10/28 2013.
[56] F. Schwierz, J. Pezoldt, and R. Granzner, "Two-dimensional materials and their prospects in transistor electronics," Nanoscale, 10.1039/C5NR01052G vol. 7, no. 18, pp. 8261-8283, 2015.
[57] S. Lee, A. Tang, S. Aloni, and H. S. Philip Wong, "Statistical Study on the Schottky Barrier Reduction of Tunneling Contacts to CVD Synthesized MoS2," Nano Lett., vol. 16, no. 1, pp. 276-281, 2016/01/13 2016.
[58] I. Ferain, C. A. Colinge, and J.-P. Colinge, "Multigate transistors as the future of classical metal–oxide–semiconductor field-effect transistors," Nature, vol. 479, p. 310, 11/16/online 2011.
[59] Y. Yoon, K. Ganapathi, and S. Salahuddin, "How Good Can Monolayer MoS2 Transistors Be?," Nano Lett., vol. 11, no. 9, pp. 3768-3773, 2011/09/14 2011.
[60] L. Xie et al., "Graphene-Contacted Ultrashort Channel Monolayer MoS2 Transistors," Adv. Mater., vol. 29, no. 37, p. 1702522, 2017/10/01 2017.
[61] D. J. Late, B. Liu, H. S. S. R. Matte, V. P. Dravid, and C. N. R. Rao, "Hysteresis in Single-Layer MoS2 Field Effect Transistors," ACS Nano, vol. 6, no. 6, pp. 5635-5641, 2012/06/26 2012.
[62] Y. Guo et al., "Charge trapping at the MoS2-SiO2 interface and its effects on the characteristics of MoS2 metal-oxide-semiconductor field effect transistors," Appl. Phys. Lett., vol. 106, no. 10, p. 103109, 2015/03/09 2015.
[63] J. Shu, G. Wu, Y. Guo, B. Liu, X. Wei, and Q. Chen, "The intrinsic origin of hysteresis in MoS2 field effect transistors," Nanoscale, 10.1039/C5NR07336G vol. 8, no. 5, pp. 3049-3056, 2016.
[64] D. Kufer and G. Konstantatos, "Highly Sensitive, Encapsulated MoS2 Photodetector with Gate Controllable Gain and Speed," Nano Lett., vol. 15, no. 11, pp. 7307-7313, 2015/11/11 2015.
[65] K. S. Kim et al., "Large-scale pattern growth of graphene films for stretchable transparent electrodes," Nature, vol. 457, p. 706, 01/14/online 2009.
[66] L. Gao, G.-X. Ni, Y. Liu, B. Liu, A. H. Castro Neto, and K. P. Loh, "Face-to-face transfer of wafer-scale graphene films," Nature, vol. 505, p. 190, 12/11/online 2013.
[67] X. Hong, A. Posadas, K. Zou, C. H. Ahn, and J. Zhu, "High-Mobility Few-Layer Graphene Field Effect Transistors Fabricated on Epitaxial Ferroelectric Gate Oxides," Phys. Rev. Lett., vol. 102, no. 13, p. 136808, 04/02/ 2009.
[68] L. Gao et al., "Repeated growth and bubbling transfer of graphene with millimetre-size single-crystal grains using platinum," Nature Communications, Article vol. 3, p. 699, 02/28/online 2012.
[69] Z. Liu, A. A. Bol, and W. Haensch, "Large-Scale Graphene Transistors with Enhanced Performance and Reliability Based on Interface Engineering by Phenylsilane Self-Assembled Monolayers," Nano Lett., vol. 11, no. 2, pp. 523-528, 2011/02/09 2011.
[70] H. Zhong, Z. Zhang, H. Xu, C. Qiu, and L.-M. Peng, "Comparison of mobility extraction methods based on field-effect measurements for graphene," AIP Advances, vol. 5, no. 5, p. 057136, 2015/05/01 2015.
[71] J.-P. Colinge, "Multiple-gate SOI MOSFETs," Solid·State Electron., vol. 48, no. 6, pp. 897-905, 2004/06/01/ 2004.
[72] S. Salahuddin and S. Datta, "Can the subthreshold swing in a classical FET be lowered below 60 mV/decade?," in 2008 IEEE International Electron Devices Meeting, 2008, pp. 1-4.
[73] S. D. Namgung, S. Yang, K. Park, A.-J. Cho, H. Kim, and J.-Y. Kwon, "Influence of post-annealing on the off current of MoS2 field-effect transistors," Nanoscale Res Lett, journal article vol. 10, no. 1, p. 62, February 11 2015.
[74] C. Lee, H. Yan, L. E. Brus, T. F. Heinz, J. Hone, and S. Ryu, "Anomalous Lattice Vibrations of Single- and Few-Layer MoS2," ACS Nano, vol. 4, no. 5, pp. 2695-2700, 2010/05/25 2010.
[75] H. Liu et al., "Phosphorene: An Unexplored 2D Semiconductor with a High Hole Mobility," ACS Nano, vol. 8, no. 4, pp. 4033-4041, 2014/04/22 2014.
[76] W. Wang, A. Klots, D. Prasai, Y. Yang, K. I. Bolotin, and J. Valentine, "Hot Electron-Based Near-Infrared Photodetection Using Bilayer MoS2," Nano Lett., vol. 15, no. 11, pp. 7440-7444, 2015/11/11 2015.
[77] M. M. Furchi, D. K. Polyushkin, A. Pospischil, and T. Mueller, "Mechanisms of Photoconductivity in Atomically Thin MoS2," Nano Lett., vol. 14, no. 11, pp. 6165-6170, 2014/11/12 2014.
[78] Y. Lee et al., "Trap-induced photoresponse of solution-synthesized MoS2," Nanoscale, 10.1039/C6NR00654J vol. 8, no. 17, pp. 9193-9200, 2016.
[79] Z. Yin et al., "Single-Layer MoS2 Phototransistors," ACS Nano, vol. 6, no. 1, pp. 74-80, 2012/01/24 2012.
[80] W. Choi et al., "High-Detectivity Multilayer MoS2 Phototransistors with Spectral Response from Ultraviolet to Infrared," Adv. Mater., vol. 24, no. 43, pp. 5832-5836, 2012/11/14 2012.
[81] S. Tongay et al., "Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons," Scientific Reports, Article vol. 3, p. 2657, 09/13/online 2013.
[82] J. Wu et al., "Layer Thinning and Etching of Mechanically Exfoliated MoS2 Nanosheets by Thermal Annealing in Air," Small, vol. 9, no. 19, pp. 3314-3319, 2013/10/11 2013.
[83] K. Kaasbjerg, K. S. Thygesen, and K. W. Jacobsen, "Phonon-limited mobility in n-type single-layer MoS2 from first principles," Physical Review B, vol. 85, no. 11, p. 115317, 03/23/ 2012.
[84] C. Jang, S. Adam, J. H. Chen, E. D. Williams, S. Das Sarma, and M. S. Fuhrer, "Tuning the Effective Fine Structure Constant in Graphene: Opposing Effects of Dielectric Screening on Short- and Long-Range Potential Scattering," Phys. Rev. Lett., vol. 101, no. 14, p. 146805, 10/03/ 2008.
[85] D. Jena and A. Konar, "Enhancement of Carrier Mobility in Semiconductor Nanostructures by Dielectric Engineering," Phys. Rev. Lett., vol. 98, no. 13, p. 136805, 03/30/ 2007.
[86] W. L. Scopel, R. H. Miwa, T. M. Schmidt, and P. Venezuela, "MoS2 on an amorphous HfO2 surface: An ab initio investigation," J. Appl. Phys., vol. 117, no. 19, p. 194303, 2015/05/21 2015.
[87] G. G. Shahidi, D. A. Antoniadis, and H. I. Smith, "Electron velocity overshoot at room and liquid nitrogen temperatures in silicon inversion layers," IEEE Electron Device Letters, vol. 9, no. 2, pp. 94-96, 1988.
[88] A. Allain, J. Kang, K. Banerjee, and A. Kis, "Electrical contacts to two-dimensional semiconductors," Nature Materials, Review Article vol. 14, p. 1195, 11/20/online 2015.
[89] H.-Y. Chang, W. Zhu, and D. Akinwande, "On the mobility and contact resistance evaluation for transistors based on MoS2 or two-dimensional semiconducting atomic crystals," Appl. Phys. Lett., vol. 104, no. 11, p. 113504, 2014/03/17 2014.
[90] T.-Y. Kim et al., "Electrical Properties of Synthesized Large-Area MoS2 Field-Effect Transistors Fabricated with Inkjet-Printed Contacts," ACS Nano, vol. 10, no. 2, pp. 2819-2826, 2016/02/23 2016.
[91] K. L. Ganapathi, S. Bhattacharjee, S. Mohan, and N. Bhat, "High-Performance HfO2 Back Gated Multilayer MoS2 Transistors," IEEE Electron Device Letters, vol. 37, no. 6, pp. 797-800, 2016.
[92] G. J. Hu, C. Chi, and C. Yu-Tai, "Gate-voltage-dependent effective channel length and series resistance of LDD MOSFET's," IEEE Trans. Electron Devices, vol. 34, no. 12, pp. 2469-2475, 1987.
[93] J. Kang, W. Liu, and K. Banerjee, "High-performance MoS2 transistors with low-resistance molybdenum contacts," Appl. Phys. Lett., vol. 104, no. 9, p. 093106, 2014/03/03 2014.
[94] W. S. Leong, X. Luo, Y. Li, K. H. Khoo, S. Y. Quek, and J. T. L. Thong, "Low Resistance Metal Contacts to MoS2 Devices with Nickel-Etched-Graphene Electrodes," ACS Nano, vol. 9, no. 1, pp. 869-877, 2015/01/27 2015.
[95] S. Lee, Y. Song, H. Park, A. Zaslavsky, and D. C. Paine, "Channel scaling and field-effect mobility extraction in amorphous InZnO thin film transistors," Solid·State Electron., vol. 135, pp. 94-99, 2017/09/01/ 2017.
[96] H. Liu et al., "Statistical Study of Deep Submicron Dual-Gated Field-Effect Transistors on Monolayer Chemical Vapor Deposition Molybdenum Disulfide Films," Nano Lett., vol. 13, no. 6, pp. 2640-2646, 2013/06/12 2013.
[97] A. Nourbakhsh et al., "15-nm channel length MoS2 FETs with single- and double-gate structures," in 2015 Symposium on VLSI Technology (VLSI Technology), 2015, pp. T28-T29.
[98] A. Rai et al., "Air Stable Doping and Intrinsic Mobility Enhancement in Monolayer Molybdenum Disulfide by Amorphous Titanium Suboxide Encapsulation," Nano Lett., vol. 15, no. 7, pp. 4329-4336, 2015/07/08 2015.
[99] L. Yang et al., "Chloride Molecular Doping Technique on 2D Materials: WS2 and MoS2," Nano Lett., vol. 14, no. 11, pp. 6275-6280, 2014/11/12 2014.
[100] W. Park et al., "Contact resistance reduction using Fermi level de-pinning layer for MoS2 FETs," in 2014 IEEE International Electron Devices Meeting, 2014, pp. 5.1.1-5.1.4.
[101] J. Kang, W. Liu, D. Sarkar, D. Jena, and K. Banerjee, "Computational Study of Metal Contacts to Monolayer Transition-Metal Dichalcogenide Semiconductors," Physical Review X, vol. 4, no. 3, p. 031005, 07/14/ 2014.
[102] R. Kappera et al., "Phase-engineered low-resistance contacts for ultrathin MoS2 transistors," Nature Materials, Article vol. 13, p. 1128, 08/31/online 2014.
[103] W. Liu, D. Sarkar, J. Kang, W. Cao, and K. Banerjee, "Impact of Contact on the Operation and Performance of Back-Gated Monolayer MoS2 Field-Effect-Transistors," ACS Nano, vol. 9, no. 8, pp. 7904-7912, 2015/08/25 2015.
[104] J. Kwon et al., "Thickness-dependent Schottky barrier height of MoS2 field-effect transistors," Nanoscale, 10.1039/C7NR01501A vol. 9, no. 18, pp. 6151-6157, 2017.
[105] Y. Lingming et al., "High-performance MoS2 field-effect transistors enabled by chloride doping: Record low contact resistance (0.5 kΩ·µm) and record high drain current (460 µA/µm)," in 2014 Symposium on VLSI Technology (VLSI-Technology): Digest of Technical Papers, 2014, pp. 1-2.