1、1/51,第九章基于STM/AFM的纳米计量技术,2/51,9.1 计量的定义9.2 纳米计量的任务和标准9.3 双元扫描隧道显微镜DTU-STM9.4 双元STM-AFM9.5 双元AFM9.6 干涉计量型AFM,第九章 基于STM/AFM的纳米计量技术,3/51,计量，是实现单位统一和量值准确可靠的测量。它属于测量，源于测量，而又严于一般测量，是测量的一种特定形式。,什么是计量?,9.1 计量的定义,4/51,计 量 Detection测 量 Measurement测 试 Metrology检 测 Test,计 测 Metrology & Measurement,相关术语,5/51,什么是
2、标准1米?, 1872年，巴黎，标准米尺（参照地球 椭球子午线弧长）? 1960年，1米是氪-86原子的2P10 和5d5 能级之间跃迁辐射在真空中的波长的 1650763.73倍（参照光波长） 1983年，第17届国际计量会议，1米是 光在真空中 299792458分之一秒时间内 所传播的距离。,6/51,为什么要纳米计量?, 隧道电流或原子力的原理性误差 压电陶瓷扫描器的迟滞与非线性 不同STM或不同AFM仪器的不一致性 不同控制系统造成的误差 人为因素的影响 环境因素的影响等,7/51,硅原子的STM图像,哪一幅更真实?,8/51,压电陶瓷的非线性AFM图像扭曲,9/51,压电陶瓷的非线
3、性AFM图像畸变,？,？,哪一颗更真实?,10/51,国外著名AFM设备对同一光栅的扫描图像,Veeco,PNI,AMBIOS,SEM,11/51,12/51,STM/AFM图像的由来?,Image(x, y, z),13/51,Image(x,y,z) Image(Ux,Uy,z),理想化x = Ux X 扫描电压值y = Uy Y 扫描电压值z = 隧道电流(STM) 光电流(AFM),实际上x Ux X 扫描电压值y Uy Y 扫描电压值z = 隧道电流(STM) 光电流(AFM) ？,14/51,结论：常规的STM和AFM都是微纳观察/测量/测试/检测型而不是微纳米计量型,15/51,
4、9.2 纳米计量的任务和标准,16/51,长度计量的标准,标准米尺,激光波长,计量光栅,?,17/51,标准样品二维点阵Const=500nm,18/51,标准光栅Const=500nm, 每毫米2000线,19/51,German Metrology Institute,20/51,20/80,21/51,标准(高度)样品Height=3000 nm,22/51,National Institute of Standards & Technology （NIST，美国国家标准技术所）,http:/www.nist.gov/index.html,23/51,Reference scale,St
5、able,Well-defined,Universal,Nano/atomic Scale,24/51,纳米计量的标尺原子尺,25/51,Dual tunneling unit STM, DTUSTM,For high resolution length measurement, the wavelength of light is generally employed as the length standard in some systems such as laser interferometers. In the nano-technology field, however, the
6、need for a more precise length measuring scale is becoming apparent. The application of regular crystalline lattice of HOPG as a reference scale in scanning tunneling microscopy (STM) has been studied.,9.3 双元扫描隧道显微镜,26/51,如何实现纳米计量？游标卡尺的启示,27/51,原子尺纳米计量的基本原理,LNCont,被测方,参考方原子,28/51,A Setup of the DTU-
7、STM,29/51,STM images of HOPG and test sample are simul-taneously scanned by one single XY scanner. The length in test sample image could be measured by counting the number of HOPG lattices.,30/51,DTUSTM获得的原子图像及纳米计量结果,（a）Reference side,（b）Test side,31/51,?,?,各种形式的DTUSTM系统,32/51,各种形式的DTUSTM系统,L,STM im
8、age of referenceSample (periodic features),STM image of test sample,reference unit,test unit,XY scanner,test sample,reference sample,33/51,Dual imaging unit STMAFM,A DTU-STM is only capable of measuring electrically conductive samples. Before surface measurements of non-conductor samples, a thin fil
9、m of conductive material should be deposited onto the sample surface. This process is troublesome and undoubtedly changes the original structure of sample surface. For direct measurement of non-conductor samples, we have further developed a dual imaging unit STM-AFM for length measurement based on s
10、tandard reference scales.,9.4 双元STMAFM,34/51,双元STMAFM原理示意图,参考标样,被测样品,35/51,(a),(b),36/51,Dual imaging unit AFM,The system incorporates two AFM units and one single XY scanner. The reference unit and the test unit are horizontally set in parallel with each other. Their probes with Z piezos and tips a
11、re installed at the same height. Such a setup can significantly reduce Abbes errors, i.e., errors due to geometric asymmetry, even if the scanner is slightly twisting. Samples with periodic features such as an alumina film and a grating are used as reference scales, respectively, for nanometer and m
12、icron order measurement.,40/80,9.5 双元AFM,37/51,PZ1,reference sample,XY Scanner,PZ2,test sample,tip 1,tip 2,双元AFM原理示意图,38/51,(a),A,B,C,39/51,40/51,计量型AFM，指的是在常规AFM的基础上，引入微型光纤传导激光干涉三维测量系统，自动校准和绝对测量样品尺度的AFM系统。它的诞生，可使目前用于纳米技术研究的STM和AFM定量化，并将其所测量的纳米量值直接与米的定义相衔接。使人们更加准确地了解纳米范围内的各种物理现象，并对它们进行更精确的分析。,Metrol
13、ogical Atomic Force Microscope,9.6 干涉计量型AFM,41/51,计量型原子力显微镜原理图,Z向激光干涉仪,X向激光干涉仪,Y向激光干涉仪,XYZ压电陶瓷驱动器,测量工作台,被测物体,立方体平面反射镜,Y,X,Z,42/51,43/51,在校准之前，当x轴、y轴和z轴的测量范围分别为15m时，x轴、y和z轴的非线性误差分别为12nm、12nm和15nm；校准后， x轴、 y轴和z轴的非线性误差仅为1nm。如果校准更加完善，没有压电陶瓷扫描驱动系统所产生的随机误差的影响，校准效果会更理想。,平移误差的校准结果,44/51,Novel Metrological AFM (1),45/51,46/51,Novel Metrological AFM (2),47/51,计量型AFM的纳米测试计量结果之一,48/51,计量型AFM的纳米测试计量结果之二,49/51,计量型AFM的纳米测试计量结果之三,50/51,To be continued,51/51,准分子激光(ArF/KrF) Ar+离子激光 红宝石激光 氦氖激光 Nd：YAG 半导体激光(例1，如AFM) 半导体激光(例2，如光通讯) CO2激光,193/248 nm 514.5 nm 694.3 nm 632.8 nm 1.06 m 650 nm 1.55 m 10.6 m,部分激光波长 ,
