双探针原子力显微镜视觉对准系统
|
摘要
传统的原子力显微镜(AFM)受针尖形状和放置方式的影响很难测量线条的宽度和两个侧壁的形状,故本文提出采用双探针对顶测量方案来消除AFM针尖形状对测量结果的影响。介绍了一种基于机器视觉的双探针原子力显微镜对准系统,该系统将两个探针接触到一起,实现了双探针在三维方向上的对准。系统采用具有亚微米级分辨率的镜头,配合高分辨率的CCD来获得探针的清晰图像,用于在水平和垂直两个方向实时监控双探针的运动情况。采用基于石英音叉式的自传感自调节的原子力探针,无需外加光学探测系统,缩小了系统体积,避免了杂散光对视觉对准系统的干扰。最后对针尖进行了亚像素边缘提取,精确地获取了探针之间的相对位置,实现了亚微米级的双探针对准(1μm以内)。该结论由探针之间距离与幅度/相位曲线得到了验证。
When a traditional Atomic Force Microscope(AFM)is used to measure the critical dimension(CD)of a line,the line width and the shape of two side-walls are difficult to be measured due to the probe shape and positioning.Therefore,this paper proposes a AFM with dual probes to eliminate the effect of probe shapes on measuring results.A alignment system based on machine vision for the AFM with dual probes was introduced,the system contacted the two probes each other to implement the alignment of the two probes in 3Ddirections.A lens with sub-micron resolution was used in the system to match a high resolution CCD to obtain the clear images and to acquire the movement states of two probes in both horizontal and vertical directions.Furthermore,the novel self-sensing and self-actuating probe based on a quartz tuning fork combined was used for dynamic mode AFM to simplify the system,by which it not needed the external optical detection system,and its dimension was shortened and the affect come from stray light was eliminated.Finally,by extracting sub pixel edge of the tips,the related position between two probes was obtained accurately and the alignment of two probes in sub micron(within 1μm)was implemented.The results were verified by the distance between two probes and amplitude/phase curves.
When a traditional Atomic Force Microscope(AFM)is used to measure the critical dimension(CD)of a line,the line width and the shape of two side-walls are difficult to be measured due to the probe shape and positioning.Therefore,this paper proposes a AFM with dual probes to eliminate the effect of probe shapes on measuring results.A alignment system based on machine vision for the AFM with dual probes was introduced,the system contacted the two probes each other to implement the alignment of the two probes in 3Ddirections.A lens with sub-micron resolution was used in the system to match a high resolution CCD to obtain the clear images and to acquire the movement states of two probes in both horizontal and vertical directions.Furthermore,the novel self-sensing and self-actuating probe based on a quartz tuning fork combined was used for dynamic mode AFM to simplify the system,by which it not needed the external optical detection system,and its dimension was shortened and the affect come from stray light was eliminated.Finally,by extracting sub pixel edge of the tips,the related position between two probes was obtained accurately and the alignment of two probes in sub micron(within 1μm)was implemented.The results were verified by the distance between two probes and amplitude/phase curves.
引文
[1]陈代谢,殷博华,林云生,等.大范围高速原子力显微镜的前馈反馈混合控制方法[J].光学精密工程,2011,19(4):836-843.CHEN D X,YIN B H,LIN Y S,et al..Feedforward and feed-back controller for large-range and high-speed AFM[J].Opt.Precision Eng.,2011,19(4):836-843.(in Chinese)
[2]高思田,叶孝佑,邵宏伟,等.用于纳米级三维表面形貌及微小尺寸测量的原子力显微镜[J].制造技术与机床,2004,8:34-39.GAO S T,YE X Y,SH H W,et al..Atomic force microscope for nanometer 3Dsurface shape and micro size measuring[J].Manufacturing Technology&Machine Tool,2004,8:34-39.(in Chinese)
[3]FRANZ J,GIESSIBL.Advances in atomic force microscopy[J].Reviews of Modern Physics,2003,7(75):949-978.
[4]ADAM W,MAYER J R R.A robust method for probe tip radius correction in coordinate metrology[J].Measurement Science and Technology,2012,23.
[5]SANTIAGO D S.Characterization of deepnanoscale surface trenches with AFM using thin carbon nanotube probes in amplitude-modulation and frequency-forcemodulation modes[J].Measurement Science and Technology,2008,19(1):015503-1-10.
[6]NDUBUISI G O,THEODORE V V,JOSEPH F,et al..Line edge roughness metrology using atomic force microscopes[J].Measurement Science and Technology,2005,16:2147-2154.
[7]MANCEVSKI V,MCCLURE P F.Development of a dual-probe CaliperTM CD-AFM for near model independent nanometrology[C].Proc.SPIE,2003,4689,:83-91.
[8]TERUNOBU A,NICOLAAS F,DE ROOIJ,et al..Implementation and characterization of a quartz tuning fork based probe consisted of discrete resonators for dynamic mode atomic force microscopy[J].Review of Scientific Instruments,2010,81,063706.
[9]AKIYAMA T,STAUFER U,DE ROOIJ N F,et al..Symmetrically arranged quartz tuning fork with soft cantilever for intermittent contact mode atomic force microscopy[J].Review of Scientific Instruments,2003,74(1):112-117.
[10]丁兴号,邓善熙,杨永跃,等.基于空间矩和Zernike矩的亚像素边缘检测[J].应用科学学报,2004,22(2):191-194.DING X H,DENG SH X,YANG Y Y,et al..Subpixel edge detection based on spatial moment and zernike moment[J].Journal of Applied Sciences,2004,22(2):191-194.(in Chinese)
[11]李金泉,王建伟,陈善本,等.一种改进的Zernike正交矩亚像素边缘检测算法[J].光学技术,2003,29(4):500-503.LI J Q,WANG J W,CHEN SH B,et al..Improved algorithm of subpixel edge detection using Zernike orthogonal moments[J].Optical Technique,2003,29(4):500-503.(in Chinese)
[12]ANCZYKOWSKI B,GOTSMANN B,FUCHS H,et al..How to measure energy dissipation in dynamic mode atomic force microscopy[J].Applied Surface Science,1999,140(3-4):376-382.
[13]WANG L L,LU M ZH,GUO T,et al..Simulation and signal analysis of Akiyama probe applied to atomic force microscope[C].Proc.SPIE8916,Sixth International Symposium on Precision Mechanical Measurements,2013.
[2]高思田,叶孝佑,邵宏伟,等.用于纳米级三维表面形貌及微小尺寸测量的原子力显微镜[J].制造技术与机床,2004,8:34-39.GAO S T,YE X Y,SH H W,et al..Atomic force microscope for nanometer 3Dsurface shape and micro size measuring[J].Manufacturing Technology&Machine Tool,2004,8:34-39.(in Chinese)
[3]FRANZ J,GIESSIBL.Advances in atomic force microscopy[J].Reviews of Modern Physics,2003,7(75):949-978.
[4]ADAM W,MAYER J R R.A robust method for probe tip radius correction in coordinate metrology[J].Measurement Science and Technology,2012,23.
[5]SANTIAGO D S.Characterization of deepnanoscale surface trenches with AFM using thin carbon nanotube probes in amplitude-modulation and frequency-forcemodulation modes[J].Measurement Science and Technology,2008,19(1):015503-1-10.
[6]NDUBUISI G O,THEODORE V V,JOSEPH F,et al..Line edge roughness metrology using atomic force microscopes[J].Measurement Science and Technology,2005,16:2147-2154.
[7]MANCEVSKI V,MCCLURE P F.Development of a dual-probe CaliperTM CD-AFM for near model independent nanometrology[C].Proc.SPIE,2003,4689,:83-91.
[8]TERUNOBU A,NICOLAAS F,DE ROOIJ,et al..Implementation and characterization of a quartz tuning fork based probe consisted of discrete resonators for dynamic mode atomic force microscopy[J].Review of Scientific Instruments,2010,81,063706.
[9]AKIYAMA T,STAUFER U,DE ROOIJ N F,et al..Symmetrically arranged quartz tuning fork with soft cantilever for intermittent contact mode atomic force microscopy[J].Review of Scientific Instruments,2003,74(1):112-117.
[10]丁兴号,邓善熙,杨永跃,等.基于空间矩和Zernike矩的亚像素边缘检测[J].应用科学学报,2004,22(2):191-194.DING X H,DENG SH X,YANG Y Y,et al..Subpixel edge detection based on spatial moment and zernike moment[J].Journal of Applied Sciences,2004,22(2):191-194.(in Chinese)
[11]李金泉,王建伟,陈善本,等.一种改进的Zernike正交矩亚像素边缘检测算法[J].光学技术,2003,29(4):500-503.LI J Q,WANG J W,CHEN SH B,et al..Improved algorithm of subpixel edge detection using Zernike orthogonal moments[J].Optical Technique,2003,29(4):500-503.(in Chinese)
[12]ANCZYKOWSKI B,GOTSMANN B,FUCHS H,et al..How to measure energy dissipation in dynamic mode atomic force microscopy[J].Applied Surface Science,1999,140(3-4):376-382.
[13]WANG L L,LU M ZH,GUO T,et al..Simulation and signal analysis of Akiyama probe applied to atomic force microscope[C].Proc.SPIE8916,Sixth International Symposium on Precision Mechanical Measurements,2013.