Chaste J, Lechner L, Morfin P, Fève G, Kontos T, Berroir J-M, Glattli D C, Happy H, Hakonen P, Plaçais B
Laboratoire Pierre Aigrain, Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris, France.
Nano Lett. 2008 Feb;8(2):525-8. doi: 10.1021/nl0727361. Epub 2008 Jan 30.
We report on microwave operation of top-gated single carbon nanotube transistors. From transmission measurements in the 0.1-1.6 GHz range, we deduce device transconductance gm and gate-nanotube capacitance Cg of micro- and nanometric devices. A large and frequency-independent gm approximately 20 microS is observed on short devices, which meets the best dc results. The capacitance per unit gate length of 60 aF/microm is typical of top gates on a conventional oxide with epsilon approximately 10. This value is a factor of 3-5 below the nanotube quantum capacitance which, according to recent simulations, favors high transit frequencies fT=gm/2piCg. For our smallest devices, we find a large fT approximately 50 GHz with no evidence of saturation in length dependence.
我们报道了顶部栅极单碳纳米管晶体管的微波操作。通过在0.1 - 1.6 GHz范围内的传输测量,我们推导出了微米级和纳米级器件的跨导(g_m)和栅极 - 纳米管电容(C_g)。在短器件上观察到一个大的且与频率无关的(g_m),约为20微西门子,这与最佳的直流结果相符。每单位栅极长度60阿法/微米的电容是具有约10的介电常数的传统氧化物上顶部栅极的典型值。该值比纳米管量子电容低3 - 5倍,根据最近的模拟,这有利于实现高的渡越频率(f_T = g_m / 2\pi C_g)。对于我们最小的器件,我们发现了一个大的(f_T),约为50 GHz,且没有长度依赖性饱和的迹象。