图1 (a) 退火后TiC与SWCNT束接触处的HRTEM照片[2]; (b)退火前后SWCNT束的I-V特性曲线[2]

Fig. 1 (a) HRTEM image of the contact interface of TiC and SWCNT bundle after annealing[2]; (b) I-V curves of a SWCNT bridging two Ti pads (as illustrated in the inset) before and after annealing[2]

图2 覆盖于SWCNT上的Ti膜的XRD峰随退火温度的变化[4]

Fig. 2 Evolution of the XRD of a titanium film covering SWCNTs dispersed on a SiO2/Si substrate as a function of temperature[4]

图3 (a)Co电极CNTFET的Id-Vgs曲线(图中右侧曲线为Id-Vgs的对数关系曲线); (b)Ti电极CNTFET的Id-Vgs曲线(图中右侧为lgId-Vgs关系曲线)[3]

Fig. 3 Id-Vgs curves of the Co contacted CNTFET (a) and the Ti contacted CNTFET (b); The right curves in the figures are the logarithmic plot of Id-Vgs characteristics[3]

图4 三个样品CNT二端电阻随热处理温度的关系图[7]

Fig. 4 Contact resistance as a function of the rapid thermal annealing (RTA) tem-perature for three different nanotube–Ti–Au electrodes[7]

图5 电脉冲处理过程示意图[15]

Fig. 5 A schematic diagram of the apparatus for the local CNT/electrode contact treatment using an electrical pulse shot[15]

图6 金属性(a)和半导体性(b)SWCNT退火前(空白区)与退火后(阴影区)的二端电阻[15]

Fig. 6 Statistics of the changes in the 2-terminal resistance before (blank) and after (shadow) pulse annealing for the cases of an individual (a) metallic SWCNT and (b) semiconducting SWCNT[15]

图7 (a) CNT末端移向金电极表面过程示意图[16]; (b) 空心和实心点线分别为MWCNT与金电极刚接触上和加电压一段时间嵌入金电极表面后的I-V曲线[16]

Fig. 7 (a) Illustration of the procedure for connecting a carbon nanotube to a gold surface[16]; (b) Current-voltage curves for two different contact states: open circles are data obtained when the MWCNT tip is just in contact with the gold surface and filled circles are for when the tip is embedded in the gold surface[16]

图8 (a)电子束沉积处理过程示意图; (b)流经CNT的电流随电子束沉积时间变化的曲线图[26]

Fig. 8 (a) Schematic diagram of the process of electron beam deposition; (b) Current vs deposition time during soldering of the MWCNT using the electron beam[26]

图9 (a) 电子束沉积法处理后CNT与金电极接触处的SEM照片; (b) 电子束沉积法处理前(黑)和处理后(灰)CNT的I-V与G-V特性[27]

Fig. 9 (a) The SEM image of the contacts of CNT and gold pads after top metal deposition; (b) The I-V and G-V curves before (black) and after (gray) the electron beam deposition[27]

图10 (a)电子束辐照CNT与金电极接触处的示意图, 阴影区为电子束辐射区域[29]; (b) CNT二端电阻与电子束辐照剂量的关系图[29]

Fig. 10 (a) Schematic of exposing the CNT/Au contacts under electron beam. The shadows show the areas of electron beam irritation[29]; (b) Two-terminal resistance R2t as a function of electron exposure dose in SEM[29]

图11 CNT与硅悬臂梁表面的Pt金属在电子束辐照改善接触后的SEM照片[30]

Fig. 11 SEM image of the contact between CNT and metal Pt on Si cantilever surface after electron beam irradiation[30]

图12 超声纳米焊接工艺示意图[32]

Fig. 12 Schematic diagrams of the ultrasonic nanowelding process[32] (a) Before welding; (b) After welding

图13 (a) 金属性SWCNT的二端电阻值随超声焊接功率的变化关系; 插图为对43个样品焊接后得到的最低二端电阻值进行统计分析和分布拟合, 得出焊接后最低电阻主要集中在15 kΩ左右[32]; (b) 制作的CNTFET的输出特性曲线; 插图为其转移特性曲线[32]

Fig. 13 (a) Two-terminal (2t-) resistance as a function of the ultrasonic power for two metallic nanotube; Inset: the statistical analysis and distribution fit of the obtained lowest 2t-resistances for 43 samples after nanowelding, which indicates that the lowest resistance is about 15 kΩ[32]; (b) Output characteristic of the fabricated CNTFET. Inset: transfer characteristic curve[32]