用于线宽测量的双探针原子力显微镜

Dual-probes Atomic Force Microscope for True Three-dimensional Line Width Measurement

双探针原子力显微镜可以有效地消除传统原子力显微镜的探针形状对线宽测量的影响,实现线宽的真三维测量。双探针原子力显微镜测量装置由测头系统、双探针扫描系统、视觉对准系统、位移测量系统构成。测头系统中采用了自感应式音叉探针简化结构。双探针测量方法共分为2步:第1步,通过2探针的接触对准确定测量坐标零点;第2步,2探针分别扫描待测线宽两侧壁,根据已确定的坐标零点拼合2次扫描所得的位移数据,从而计算可得线宽值。接触对准中,利用了图像边缘提取定位和针尖反馈扫描对准相结合的探针对准方法,提高了对针精度。

Dual-probe atomic force microscope( AFM) can effectively eliminate the influence of the probe size on measurement of the line width,and realize true three-dimensional measurement. Dual-probe AFM consists of probe system,scanning system,alignment system and displacement measurement system. In order to simplify the dual-probe AFM structure,self-sensing tuning fork probe is used. Measurement method has two steps: the first step is to align two probes and obtain the reference point; the second step is to scan two sides of measured line by two probes separately,and calculate the line width value according to the reference point. In the alignment of two probes,the alignment method is improved by using the edge alignment and the feedback scanning alignment.