High-speed graphene transistors with a self-aligned nanowire gate.
High-speed graphene transistors with a self-aligned nanowire gate.
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石墨烯作为一种潜在的新型电子材料引起了人们的极大兴趣。石墨烯具有最高的载流子迁移率超过200,000 cm2/V·S，因此在超高速射频(RF)电子设备中具有特殊的应用价值。然而，传统的介质集成和器件制造工艺不能很容易地应用于高速石墨烯晶体管的制造，因为它们往往会在碳单层中引入显著的缺陷，并严重降低器件的性能。在这里，我们报告了一种新的方法来制造具有自对准纳米线栅极的高速石墨烯晶体管，以实现前所未有的性能。石墨烯晶体管采用Co2Si/Al_2O_3核/壳纳米线作为栅极，源极和漏极通过自对准工艺定义，沟道长度由纳米线直径定义。纳米线栅极的物理组装保留了石墨烯中的高载流子迁移率，而自对准工艺确保了源极、漏极和栅电极的边缘自动而精确地定位，从而使这些电极之间没有重叠或显著的间隙，从而将访问电阻降至最低。因此，它实现了以前不可能实现的晶体管性能。已制备出沟道长度为140 nm的石墨烯晶体管，其导通电流(3.32 mAμm−1)和跨导(1.27msμm−1)是迄今报道的最高值。值得注意的是，片上微波测量表明，自对准器件在100-300 GHz范围内表现出创纪录的本征截止频率(FT)，而在几千兆赫范围内的非本征FT在很大程度上受到寄生衬垫电容的限制。据报道，石墨烯晶体管的本征截止频率与栅长相似的最好的高电子迁移率晶体管的固有截止频率相当。因此，它标志着石墨烯射频设备的一个重要里程碑，可以为高速电子领域带来令人兴奋的机会。
Graphene has attracted considerable interest as a potential new electronic material. With the highest carrier mobility exceeding 200,000 cm2/V·s, graphene is of particular interest for ultra-high speed radio frequency (RF) electronics. However, the conventional dielectric integration and device fabrication processes cannot be readily applied to fabricate high speed graphene transistors because they can often introduce significant defects into the monolayer of carbon lattices and severely degrade the device performance. Here we report a new approach to fabricate high-speed graphene transistors with a self-aligned nanowire gate to enable unprecedented performance. The graphene transistors are fabricated using a Co2Si/Al2O3 core/shell nanowire as the gate, with the source and drain electrodes defined through a self-alignment process and the channel length defined by the nanowire diameter. The physical assembly of nanowire gate preserves the high carrier mobility in graphene, and the self-aligned process ensures that the edges of the source, drain, and gate electrodes are automatically and precisely positioned so that no overlapping or significant gaps exist between these electrodes and thus minimizes access resistance. It therefore enables transistor performance not previously possible. Graphene transistors with channel length down to 140 nm have been fabricated with the highest scaled on-current (3.32 mA μm−1) and transconductance (1.27 mS μm−1) reported to date. Significantly, on-chip microwave measurements demonstrate that the self-aligned devices exhibit a record high intrinsic cutoff frequency (fT) in the range of 100–300 GHz, with the extrinsic fT in the range of a few gigahertz largely limited by parasitic pad capacitance. The reported intrinsic cutoff frequency of the graphene transistors is comparable to that of the very best high electron mobility transistors with similar gate lengths. It therefore marks an important milestone in graphene RF devices and can enable exciting opportunities in high-speed electronics.
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影响因子：
4
作者：
Murali, Raghunath;Yang, Yinxiao;Meindl, James D.
通讯作者：
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影响因子：
56.9
作者：
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影响因子：
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作者：
Moon, J. S.;Curtis, D.;Gaskill, D. K.
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4
作者：
Lee, Bongki;Park, Seong-Yong;Kim, Jiyoung
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影响因子：
29.4
作者：
Liao, Lei;Bai, Jingwei;Lin, Yung-Chen;Qu, Yongquan;Huang, Yu;Duan, Xiangfeng
通讯作者：
Duan, Xiangfeng