高性能的電子元件需要擁有理想的通道材料和極低的接觸電阻（contact resistance）。儘管許多研究已成功將二維材料（如MoS2）用作電晶體的通道材料，但金屬與半導體界面之間的接觸電阻依然很高。傳統半導體也存在這些接觸電阻的問題，但通常可以通過選擇適當功函數(ϕm)的金屬並進行離子佈植（ion-implantation）來重摻雜，從而改善這些問題。然而，由於二維半導體結構較薄，摻雜可能會破壞其結構並改變其特性，因此無法通過這些方法來降低接觸電阻。
研究人員發現，半金屬材料的態密度幾乎為零，當與二維半導體接觸時，費米能階釘札問題不易發生。這種方法已成功應用於n型二維材料元件，通過相位控制形成半金屬作為汲極和源極。然而，關於p型二維材料FET的研究較為稀少，而且大多數製程方式僅適合少量實驗製作，並不適用於大規模生產。因此，p型二維材料元件仍需要更多研究與開發。為了解決二維材料元件中高接觸電阻的問題，本實驗加入了高壓退火製程以進一步改進。

In this study, a high-pressure annealing process was introduced to further reduce contact resistance in 2D material devices. This method improves contact quality, enhancing device performance and paving the way for broader applications of p-type 2D materials in electronic devices.

[1] C.A. Mack, Fifty years of Moore's law, IEEE Transactions on semiconductor manufacturing 24 (2011) 202-207.

[2] A. Chaudhry, M.J. Kumar, Controlling short-channel effects in deep-submicron SOI MOSFETs for improved reliability: a review, IEEE Transactions on Device and Materials Reliability 4 (2004) 99-109.

[3] Y. Liu, X. Duan, H.-J. Shin, S. Park, Y. Huang, X. Duan, Promises and prospects of two-dimensional transistors, Nature 591 (2021) 43-53.

[4] Y. Liu, X. Duan, Y. Huang, X. Duan, Two-dimensional transistors beyond graphene and TMDCs, Chemical Society Reviews 47 (2018) 6388-6409.

[5] M. Chhowalla, H.S. Shin, G. Eda, L.-J. Li, K.P. Loh, H. Zhang, The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets, Nature chemistry 5 (2013) 263-275.

[6] C. Zhang, S. Kc, Y. Nie, C. Liang, W.G. Vandenberghe, R.C. Longo, Y. Zheng, F. Kong, S. Hong, R.M. Wallace, Charge mediated reversible metal–insulator transition in monolayer MoTe2 and W x Mo1–x Te2 alloy, ACS nano 10 (2016) 7370-7375.

[7] R.T. Tung, Recent advances in Schottky barrier concepts, Materials Science and Engineering: R: Reports 35 (2001) 1-138.

[8] C. Kim, I. Moon, D. Lee, M.S. Choi, F. Ahmed, S. Nam, Y. Cho, H.-J. Shin, S. Park, W.J. Yoo, Fermi level pinning at electrical metal contacts of monolayer molybdenum dichalcogenides, ACS nano 11 (2017) 1588-1596.

[9] A. Allain, J. Kang, K. Banerjee, A. Kis, Electrical contacts to two-dimensional semiconductors, Nature materials 14 (2015) 1195-1205.

[10] P.-C. Shen, C. Su, Y. Lin, A.-S. Chou, C.-C. Cheng, J.-H. Park, M.-H. Chiu, A.-Y. Lu, H.-L. Tang, M.M. Tavakoli, Ultralow contact resistance between semimetal and monolayer semiconductors, Nature 593 (2021) 211-217.
[11] K.S. Novoselov, A.K. Geim, S.V. Morozov, D.-e. Jiang, Y. Zhang, S.V. Dubonos, I.V. Grigorieva, A.A. Firsov, Electric field effect in atomically thin carbon films, science 306 (2004) 666-669.

[12] C. Lee, Q. Li, W. Kalb, X.-Z. Liu, H. Berger, R.W. Carpick, J. Hone, Frictional characteristics of atomically thin sheets, science 328 (2010) 76-80.

[13] K.S. Novoselov, D. Jiang, F. Schedin, T. Booth, V. Khotkevich, S. Morozov, A.K. Geim, Two-dimensional atomic crystals, Proceedings of the National Academy of Sciences 102 (2005) 10451-10453.

[14] Y.-C. Lin, W. Zhang, J.-K. Huang, K.-K. Liu, Y.-H. Lee, C.-T. Liang, C.-W. Chu, L.-J. Li, Wafer-scale MoS 2 thin layers prepared by MoO 3 sulfurization, Nanoscale 4 (2012) 6637-6641.

[15] Cho, Suyeon, et al. "Phase patterning for ohmic homojunction contact in MoTe2." Science 349.6248 (2015): 625-628.

[16] Mattinen, Miika, et al. "Atomic layer deposition of crystalline molybdenum oxide thin films and phase control by post-deposition annealing." Materials today chemistry 9 (2018): 17-27.

[17]Sung, Ji Ho, et al. "Coplanar semiconductor–metal circuitry defined on few-layer MoTe2 via polymorphic heteroepitaxy." Nature nanotechnology 12.11 (2017): 1064-1070.

[18] 陳倫維。「應用高壓退火改善大面積二維材料MoTe2薄膜結晶性及電晶體電性」。碩士論文，國立成功大學奈米積體電路工程碩士博士學位學程，2022。＜https://hdl.handle.net/11296/526cqw＞。

[19]吳柏諭。「利用一次碲化形成半金屬歐姆接觸改善MoTe2電晶體特性」。碩士論文，國立成功大學微電子工程研究所，2023。＜https://hdl.handle.net/11296/7w8x5h＞。