浙江大学研究生课程—纳米技术与系统 第十章 扫描探针显微镜技术 浙江大学 2017-03-27 章海军

第十章 扫描探针显微镜技术 10.1 从STM/AFM到扫描探针显微镜 10.2 SPM家族 10.3 摩擦力显微镜(FFM) 第十章 扫描探针显微镜技术 10.1 从STM/AFM到扫描探针显微镜 10.2 SPM家族 10.3 摩擦力显微镜(FFM) 10.4 静电力显微镜(EFM) 10.5 磁力显微镜(MFM) 10.6 扫描离子电导显微镜(SICM) 10.7 扫描近场光学显微镜(SNOM) 10.8 光子扫描隧道显微镜(PSTM) 10.9 SPM总结

10.1 从STM/AFM到SPM家族 AFM 0. 1 nm 原子力显微镜 电子显微镜 扫描隧道显微镜 SPM 扫描探针显微镜 SEM 1932年 鲁斯卡&克诺尔 1982年 宾尼&罗雷尔 1986年 宾尼&夸特 AFM 0. 1 nm 原子力显微镜 电子显微镜 扫描隧道显微镜 SPM 扫描探针显微镜 SEM TEM STM 0.01 nm CNT AFM CNT STM

STM基础：量子力学—隧道效应

STM原理

原子力显微镜 Atomic force microscopy 1986, Binnig, Quate, Gerber 1989, The first commercially available AFM 1993, 第一台ZD原子力显微镜 7

AFM的光束偏转法 Beam deflection method

Basic setup of AFM

10.2 扫描探针显微镜家族 The family of scanning probe microscope, SPM 相互 作用 相互作用 Interaction 样品 Sample 隧道电流、原子力、摩擦力、静电力、磁力、热、光子流、离子流（离子电导）、电容等。 相互 作用

SPM Family Tree AFM CSPM SNOM STM Standard modes Optional modes EFM CSTM SThM LFM STM STS FFM MFM AFM EFM Standard modes Optional modes SNOM CSPM SICM CAFM PSTM SPM Family Tree

10.3 摩擦力显微镜(FFM) Principle of Friction Force Microscope

FFM的二维PSD光电检测电路系统

FFM的应用实例 AFM图像 FFM图像

AFM图像 FFM图像

FFM的功效及应用图解 AFM图像

FFM的功效及应用图解 FFM图像

阴影区代表摩擦特性不同

10.4 静电力显微镜(EFM)

2. The tip of Electrostatic Force Microscope  Typical tip radius better than 7 nm；  Electrical con- ductive coating  High mechanical Q-factor for high sensitivity. 静电微探针

An overall metallic coating (Pt-Ir5) on both sides of the cantilever increasing the electrical con-ductivity of the tip. The Pt-Ir5 coating is an approxi-mately 25 nm thick double layer of chromium and platinum- iridium5. The tip side coating enhances the conductivity of the tip and allows electrical contacts. Cantilever length: 225 m Tip radius: 7 nm～ Force Constant: 2.8N/m Resonance freq: 75 kHz Price in USD: $50/tip

AFM 图像 EFM图像

静电力显微镜(EFM)实例 Electrostatic Force Microscopy (EFM) uses a combination of TappingMode™, LiftMode™ and a conductive tip to gather information about the electric field above a sample. Each line of the sample is first scanned in TappingMode operation to obtain the sample topography. The topographic information is stored and retraced with a user- selectable height offset in LiftMode, during which the electrical data is collected. Typical lift heights in EFM range from 20-80 nm.

10.5 磁力显微镜(MFM) 磁性微探针。探测记录样品表面的磁分布。如磁盘、磁带。

F' = F'surface+F'magnetic F' = F'surface+F'magnetic The AFM operated in the non-contact mode with a magnetic cantilever detects a force gradient (F') containing information from both the surface structure and surface magnetization. F' = F'surface+F'magnetic Signals from surface topography dominate at close distances to the surface while, at greater distances from the surface (typically beyond 100 nm), the magnetic signal dominates. Consequently, depending on the distance between the surface and the tip, normal MFM images may contain a combination of topography and magnetic signals. Though it is useful to topographically locate where the magnetic domains are, sometimes it is more advantageous to completely separate the two signals from each other. F' = F'surface+F'magnetic

Magnetic force microscopy  Local magnetic properties  AFM + tip covered by a layer of ferromagnetic material with specific magnetization

Tip preparation of MFM（a） 材 料：单晶硅 形 状：圆锥形 针尖高度：7 m 针尖曲率：10 nm 圆 锥 角：10

Tip preparation of MFM（b） A typical example is shown in the picture. A carbon contamination needle is grown on top of the pyramidal tip of a commercial Si3N4 AFM cantilever. The needle is covered afterwards from one side with a thermally evaporated 15 nm thick Co80Ni20 film to make it sensitive for MFM mea- surement. Orientation of the needle is chosen to be approximately 10º with respect to the can- tilever plane.

MFM的应用实例

磁力显微镜(MFM)实例 Magnetic Force Microscopy (MFM) uses a combination of TappingMode™, LiftMode™ and a properly prepared tip to gather information about the magnetic field above a sample. Each line of the sample is first scanned in TappingMode operation to obtain the sample topography. The topographic information is stored and retraced with a user selectable height offset in LiftMode, during which the magnetic data are collected. Typical lift heights in MFM range from 20- 100 nm.

10.6 扫描离子电导显微镜（SICM） I V 毛细管微探针 micropipette capillary metal electrode sample (cathode) bath electrolyte metal electrode (anode) microstructures 毛细管微探针 capillary

Scanning Ion-conductance Microscope P. K. Hansma, B. Drake, O.Marti 扫描离子电导显微镜 Scanning Ion-conductance Microscope P. K. Hansma, B. Drake, O.Marti Science, 1989, 243, 641-643

The SICM was originally designed to image the topography of non-conducting surfaces that are covered with electrolytes by using an electrolyte-filled micropipette probe tip. As the tip approaches towards the sample surface in a reservoir of electrolytes, the ion flow through the opening of the tip is blocked at short distances between the tip and the surface, thus decreasing the ion conductance. When the tip scans over the surface, ion conductance changes with the contour of the sample surface. SICM can resolve features as small as the inner diameter of the tip. One more promising application of SICM is to image the local ion currents coming through the surfaces of the biological samples.

毛细管 毛细管微探针制备 电热丝 玻璃罩 重块 开关

毛细管 毛细管微探针制备 电热丝 玻璃罩 重块 开关

毛细管 毛细管微探针制备 电热丝 玻璃罩 重块 开关 5-31

远场 (Far field)与近场 (Near field) 10.7 扫描近场光学显微镜(SNOM) 远场 (Far field)与近场 (Near field) Far field: d > λ/(2sinθ) > 200 nm Near field : optical resolution of d < 50 nm can be achieved.

The principle and setup of SNOM Light passes through a sub-wavelength diameter aperture and illuminates a sample that is placed within its near field, at a distance (e.g., <100 nm) much less than the wavelength of the light. The resolution achieved is far better than that which conventional optical microscopes can attain. In order to make an NSOM/SNOM experiment, a point light source must be brought near the surface that will be imaged (within nanometers). The point light source must then be scanned over the surface, without touching it, and the optical signal from the surface must be collected and detected.

Typical SNOM Setup 60/89

WITEC SNOM Setup http://www.witec.de/snom.html

The Instrument of SNOM

SNOM的 操作模式

Tip preparation of SNOM  Etching Method: After the fiber is bent, the tip is etched using the protection layer technique. Using hexadecane as the protection layer and pure 40% HF as the etchant, tip radii of under 50 nm can be achieved.  Melt-drawing (Pulling) method: Melt-drawing an optical fibre using a modified Sutter Instruments (Puller) .

SNOM Aperture Probes Fiber-Pulling Chemical Etching Evanescent Decay Aluminum Deposition 300 nm 300 nm

The properties of SNOM  Changes in the index of refraction  Changes in the reflectivity  Changes in the transparency  Changes in polarization  Stress at certain points of the sample that changes its optical properties  Magnetic properties, which can change the optical properties  Fluorescent molecules  Molecules excited through a Raman shift, SHG, or other effects  Changes in the material

SNOM的应用实例  纳米尺度的光学成像  纳米尺度的光学微加工与光刻  磁光畴与超高密度磁光存储  量子器件、纳米材料、微腔激光器的发光光谱测量  生物样品的原位与动态观察  超高密度的信息存储（100 Gb/inch2）  介观体系信息提取（10－9m、10－15s）等

AFM (Left) and SNOM (right) image of gold balls with a diameter of 30 nm.

SNOM (Left) and AFM (right) image of Polymer balls

AFM SNOM

SNOM of 2D Photonic Crystals 100 nm

10.8 光子扫描隧道显微镜(PSTM) The Photon Scanning Tunneling Microscope (PSTM) relies on the local detection of the optical near-field intensity of a sample by a sharpened optical fiber. The illumination of the sample is accomplished by an evanescent field generated by total internal reflection inside a glass prism to which the sample is optically coupled. Evanescent wave or Evanescent field

The Principle of PSTM 光纤探针 Fiber Probe 瞬衰场 Evanescent field 样品 Sample 激光 光纤探针 Fiber Probe 样品 Sample 全反射 瞬衰场 Evanescent field

PSTM

补充：扫描热显微镜(SHhM) In Scanning Thermal Microscopy (SThM) a heated tip is scanned across a sample. Changes in the tip’s resistivity reveal either thermal conductivity or thermal gradients on the sample. In Nanoscale Analysis (NA), a tip is heated in such a way that it induces a phase transition in the sample. That transition is monitored using the cantilever deflection and is material specific.

补充：扫描电容显微镜(SCM) SCM uses contact mode AFM and a conductive probe and applies to semiconductor samples with an AC bias (amplitude DV, ~90 kHz) with a DC offset. The capacitance of the metal-oxide-semiconductor (MOS) capacitor at tip-sample contact is a function of majority carrier concentration in the sample. SCM uses an ultra-high-frequency (1 GHz) detector to measure tip-sample capacitance variation, DC, at the bias frequency. Sensor Signal is DC/DV. In feedback mode, output signal is DV, adjusted to maintain a DC/DV Setpoint. SCM maps relative changes of majority carrier concentration in semiconductors.

10.9 SPM系统的性能总结

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Thank you ! 本周六(4月1日见)