Thermal dissipation and variability in electrical breakdown of carbon nanotube devices
Thermal dissipation and variability in electrical breakdown of carbon nanotube devices
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DOI：
10.1103/physrevb.82.205406
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发表时间：
2010-11-05
影响因子：
3.7
通讯作者：
Pop, Eric
中科院分区：
文献类型：
--
作者：
Liao, Albert;Alizadegan, Rouholla;Pop, Eric
我们研究了SiO2衬底上碳纳米管（CNT）器件的高场电击穿和热耗散。通过分子动力学模拟揭示了碳纳米管的热“足迹”与衬底的货车范德华相互作用所造成的。实验和建模发现，碳纳米管-基底热耦合与碳纳米管直径成正比，与SiO2表面粗糙度成正比（类似于d/Delta）。扩散失配建模和数据的比较揭示了对于最大直径（类似于3.2 nm）CNT，热耦合的上限类似于室温下每单位CNT长度0.4 W K-1 m（-1）（每单位面积130 MW K-1 m（-2）），并且类似于600 ℃下0.7 W K-1 m（-1）。我们还发现，半导体碳纳米管可以过早地打破，并显示更多的可变性，由于阈值电压的动态变化，其中金属碳纳米管是免疫的，这构成了一个根本的挑战，选择性电击穿在CNT电子。
We study high-field electrical breakdown and heat dissipation from carbon nanotube (CNT) devices on SiO2 substrates. The thermal "footprint" of a CNT caused by van der Waals interactions with the substrate is revealed through molecular dynamics simulations. Experiments and modeling find the CNT-substrate thermal coupling scales proportionally with CNT diameter and inversely with SiO2 surface roughness (similar to d/Delta). Comparison of diffuse mismatch modeling and data reveals the upper limit of thermal coupling similar to 0.4 W K-1 m(-1) per unit CNT length at room temperature, (130 MW K-1 m(-2) per unit area), and similar to 0.7 W K-1 m(-1) at 600 degrees C for the largest diameter (similar to 3.2 nm) CNTs. We also find semiconducting CNTs can break down prematurely and display more variability due to dynamic shifts in threshold voltage, which metallic CNTs are immune to; this poses a fundamental challenge for selective electrical breakdowns in CNT electronics.