National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China.
School of Physics, Southeast University, Nanjing, China.
Nature. 2023 Jan;613(7943):274-279. doi: 10.1038/s41586-022-05431-4. Epub 2023 Jan 11.
The development of next-generation electronics requires scaling of channel material thickness down to the two-dimensional limit while maintaining ultralow contact resistance. Transition-metal dichalcogenides can sustain transistor scaling to the end of roadmap, but despite a myriad of efforts, the device performance remains contact-limited. In particular, the contact resistance has not surpassed that of covalently bonded metal-semiconductor junctions owing to the intrinsic van der Waals gap, and the best contact technologies are facing stability issues. Here we push the electrical contact of monolayer molybdenum disulfide close to the quantum limit by hybridization of energy bands with semi-metallic antimony ([Formula: see text]) through strong van der Waals interactions. The contacts exhibit a low contact resistance of 42 ohm micrometres and excellent stability at 125 degrees Celsius. Owing to improved contacts, short-channel molybdenum disulfide transistors show current saturation under one-volt drain bias with an on-state current of 1.23 milliamperes per micrometre, an on/off ratio over 10 and an intrinsic delay of 74 femtoseconds. These performances outperformed equivalent silicon complementary metal-oxide-semiconductor technologies and satisfied the 2028 roadmap target. We further fabricate large-area device arrays and demonstrate low variability in contact resistance threshold voltage, subthreshold swing, on/off ratio, on-state current and transconductance. The excellent electrical performance, stability and variability make antimony ([Formula: see text]) a promising contact technology for transition-metal-dichalcogenide-based electronics beyond silicon.
下一代电子器件的发展需要将沟道材料的厚度缩减到二维极限，同时保持超低的接触电阻。过渡金属二卤化物可以将晶体管的缩放持续到路线图的终点，但尽管已经做了无数的努力，器件性能仍然受到接触的限制。特别是，由于固有的范德华间隙，接触电阻尚未超过共价键合的金属半导体结的接触电阻，而且最佳的接触技术正面临稳定性问题。在这里，我们通过强范德华相互作用，使单层二硫化钼的能带与半金属锑（[Formula: see text]）杂化，从而将其电接触推近量子极限。这些接触具有低至 42 欧姆·微米的接触电阻和在 125°C 下的优异稳定性。由于接触得到改善，短沟道二硫化钼晶体管在 1 伏漏极偏压下表现出电流饱和，导通状态电流为 1.23 毫安/微米，导通/关断比超过 10，固有延迟为 74 飞秒。这些性能优于等效的硅互补金属氧化物半导体技术，并满足了 2028 年路线图的目标。我们进一步制造了大面积器件阵列，并证明了接触电阻、阈值电压、亚阈值摆幅、导通/关断比、导通状态电流和跨导的低变化性。优异的电性能、稳定性和可变性使得锑（[Formula: see text]）成为超越硅的基于过渡金属二卤化物的电子器件的一种很有前途的接触技术。
