Blind tip reconstruction(BTR) method is one of the favorable methods to estimate the atomic force microscopy(AFM) probe shape. The exact shape of the characterizer is not required for BTR, while the geometry of the sa...Blind tip reconstruction(BTR) method is one of the favorable methods to estimate the atomic force microscopy(AFM) probe shape. The exact shape of the characterizer is not required for BTR, while the geometry of the sample may affect the reconstruction significantly. A cone-shaped array sample was chosen as a characterizer to be evaluated. The target AFM probe to be reconstructed was a diamond triangular pyramid probe with two feature angles, namely front angle(FA) and back angle(BA). Four conical structures with different semi-angles were dilated by the pyramid probe. Simulation of scanning process demonstrates that it is easy to judge from the images of the isolated rotary structure, cone-shaped, the suitability of the sample to be a tip characterizer for a pyramid probe. The cone-shaped array sample was repeatedly scanned 50 times by the diamond probe using an AFM. The series of scanning images shrank gradually and more information of the probe was exhibited in the images, indicating that the characterizer has been more suitable for BTR. The feature angle FA of the characterizer increasingly reduces during the scanning process. A self-adaptive grinding between the probe and the characterizer contributes to BTR of the diamond pyramid probe.展开更多
An improved arc discharge method is developed to fabricate carbon nanotube probe of atomic force microscopy （AFM） here. First, silicon probe and carbon nanotube are manipulated under an optical microscope by two hig...An improved arc discharge method is developed to fabricate carbon nanotube probe of atomic force microscopy （AFM） here. First, silicon probe and carbon nanotube are manipulated under an optical microscope by two high precision microtranslators. When silicon probe and carbon nanotube are very close, several tens voltage is applied between them. And carbon nanotube is divided and attached to the end of silicon probe, which mainly due to the arc welding function. Comparing with the arc discharge method before, the new method here needs no coat silicon probe with metal film in advance, which can greatly reduce the fabrication＇s difficulty. The fabricated carbon nanotube probe shows good property of higher aspect ratio and can more accurately reflect the true topography of silicon grating than silicon probe. Under the same image drive force, carbon nanotube probe had less indentation depth on soft triblock copolymer sample than silicon probe. This showed that carbon nanotube probe has lower spring constant and less damage to the scan sample than silicon probe.展开更多
In this paper, a two-dimensional nanometer scale tip-plate discharge model has been employed to study nanoscale electrical discharge in atmospheric conditions. The field strength dis- tributions in a nanometer scale t...In this paper, a two-dimensional nanometer scale tip-plate discharge model has been employed to study nanoscale electrical discharge in atmospheric conditions. The field strength dis- tributions in a nanometer scale tip-to-plate electrode arrangement were calculated using the finite element analysis （FEA） method, and the influences of applied voltage amplitude and frequency as well as gas gap distance on the variation of effective discharge range （EDR） on the plate were also investigated and discussed. The simulation results show that the probe with a wide tip will cause a larger effective discharge range on the plate; the field strength in the gap is notably higher than that induced by the sharp tip probe; the effective discharge range will increase linearly with the rise of excitation voltage, and decrease nonlinearly with the rise of gap length. In addition, probe dimension, especially the width/height ratio, affects the effective discharge range in different manners. With the width/height ratio rising from 1 ： 1 to 1 ： 10, the effective discharge range will maintain stable when the excitation voltage is around 50 V. This will increase when the excitation voltage gets higher and decrease as the excitation voltage gets lower. Fhrthermore, when the gap length is 5 nm and the excitation voltage is below 20 V, the diameter of EDR in our simulation is about 150 nm, which is consistent with the experiment results reported by other research groups. Our work provides a preliminary understanding of nanometer scale discharges and establishes a predictive structure-behavior relationship.展开更多
面向原子力显微镜(atomic force microscope,AFM)探针的应用需求,提出一种基于硅尖的垂直取向碳纳米管(carbon nanotubes,CNTs)制备方法。首先,通过优化掩膜设计和KOH湿法腐蚀工艺,制备了高度约为6μm的硅尖阵列;然后,采用图案化催化剂...面向原子力显微镜(atomic force microscope,AFM)探针的应用需求,提出一种基于硅尖的垂直取向碳纳米管(carbon nanotubes,CNTs)制备方法。首先,通过优化掩膜设计和KOH湿法腐蚀工艺,制备了高度约为6μm的硅尖阵列;然后,采用图案化催化剂定位投放技术,在硅尖顶端实现了铁蛋白分子的选择性附着;最后,通过热化学气相沉积(chemical vapor deposition,CVD)法,在优化的工艺参数下,成功在硅尖上生长出直径约16~20 nm、垂直取向的单根碳纳米管。扫描电子显微镜(scanning electron microscopy,SEM)和透射电子显微镜(transmission electron microscopy,TEM)表征结果显示,所制备的CNTs结构均匀且结晶度良好;拉曼光谱分析进一步证实其具有高度石墨化特性。研究结果可为高性能AFM探针的制备提供可行的技术方案,具有重要的应用价值。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51305298,No.51675379)Tianjin Research Program of Application Foundation and Advanced Technology(Grant No.13JCQNJC04700)
文摘Blind tip reconstruction(BTR) method is one of the favorable methods to estimate the atomic force microscopy(AFM) probe shape. The exact shape of the characterizer is not required for BTR, while the geometry of the sample may affect the reconstruction significantly. A cone-shaped array sample was chosen as a characterizer to be evaluated. The target AFM probe to be reconstructed was a diamond triangular pyramid probe with two feature angles, namely front angle(FA) and back angle(BA). Four conical structures with different semi-angles were dilated by the pyramid probe. Simulation of scanning process demonstrates that it is easy to judge from the images of the isolated rotary structure, cone-shaped, the suitability of the sample to be a tip characterizer for a pyramid probe. The cone-shaped array sample was repeatedly scanned 50 times by the diamond probe using an AFM. The series of scanning images shrank gradually and more information of the probe was exhibited in the images, indicating that the characterizer has been more suitable for BTR. The feature angle FA of the characterizer increasingly reduces during the scanning process. A self-adaptive grinding between the probe and the characterizer contributes to BTR of the diamond pyramid probe.
基金This project is supported by National Natural Science Foundation of China (No.50205006).
文摘An improved arc discharge method is developed to fabricate carbon nanotube probe of atomic force microscopy （AFM） here. First, silicon probe and carbon nanotube are manipulated under an optical microscope by two high precision microtranslators. When silicon probe and carbon nanotube are very close, several tens voltage is applied between them. And carbon nanotube is divided and attached to the end of silicon probe, which mainly due to the arc welding function. Comparing with the arc discharge method before, the new method here needs no coat silicon probe with metal film in advance, which can greatly reduce the fabrication＇s difficulty. The fabricated carbon nanotube probe shows good property of higher aspect ratio and can more accurately reflect the true topography of silicon grating than silicon probe. Under the same image drive force, carbon nanotube probe had less indentation depth on soft triblock copolymer sample than silicon probe. This showed that carbon nanotube probe has lower spring constant and less damage to the scan sample than silicon probe.
基金supported in part by External Cooperation Program of Chinese Academy of Sciences(No.GJHZ1218)National Natural Science Foundation of China(No.61004133)SSSTC JRP awards 2011(IZLCZ2 138953)
文摘In this paper, a two-dimensional nanometer scale tip-plate discharge model has been employed to study nanoscale electrical discharge in atmospheric conditions. The field strength dis- tributions in a nanometer scale tip-to-plate electrode arrangement were calculated using the finite element analysis （FEA） method, and the influences of applied voltage amplitude and frequency as well as gas gap distance on the variation of effective discharge range （EDR） on the plate were also investigated and discussed. The simulation results show that the probe with a wide tip will cause a larger effective discharge range on the plate; the field strength in the gap is notably higher than that induced by the sharp tip probe; the effective discharge range will increase linearly with the rise of excitation voltage, and decrease nonlinearly with the rise of gap length. In addition, probe dimension, especially the width/height ratio, affects the effective discharge range in different manners. With the width/height ratio rising from 1 ： 1 to 1 ： 10, the effective discharge range will maintain stable when the excitation voltage is around 50 V. This will increase when the excitation voltage gets higher and decrease as the excitation voltage gets lower. Fhrthermore, when the gap length is 5 nm and the excitation voltage is below 20 V, the diameter of EDR in our simulation is about 150 nm, which is consistent with the experiment results reported by other research groups. Our work provides a preliminary understanding of nanometer scale discharges and establishes a predictive structure-behavior relationship.
文摘面向原子力显微镜(atomic force microscope,AFM)探针的应用需求,提出一种基于硅尖的垂直取向碳纳米管(carbon nanotubes,CNTs)制备方法。首先,通过优化掩膜设计和KOH湿法腐蚀工艺,制备了高度约为6μm的硅尖阵列;然后,采用图案化催化剂定位投放技术,在硅尖顶端实现了铁蛋白分子的选择性附着;最后,通过热化学气相沉积(chemical vapor deposition,CVD)法,在优化的工艺参数下,成功在硅尖上生长出直径约16~20 nm、垂直取向的单根碳纳米管。扫描电子显微镜(scanning electron microscopy,SEM)和透射电子显微镜(transmission electron microscopy,TEM)表征结果显示,所制备的CNTs结构均匀且结晶度良好;拉曼光谱分析进一步证实其具有高度石墨化特性。研究结果可为高性能AFM探针的制备提供可行的技术方案,具有重要的应用价值。
