Ellipsometric Microscope Research Articles

In-situ measurement of temporal changes in thickness of polymer adsorbed films from lubricant oil by vertical-objective-based ellipsometric microscopy

Understanding the formation mechanism and conformation of the adsorbed film formed by additives is critical to clarify the boundary lubrication characteristics. In this study, using the vertical-objective-based ellipsometric microscope (VEM), which can measure nm-gaps between solid surfaces, we proposed a new method for in-situ measuring the thickness of additive adsorbed film in the lubricant oil. In this method, the adsorbed film thickness was measured by measuring the gap between the solids, which was filled by the additive film. The formation process of polyalkylmethacrylate (PAMA) polymer additive adsorbed film was successfully observed. Moreover, we revealed that the PAMA adsorbed films adopted two different conformations depending on the molecular weight and concentration of the polymer: the flattened single-layer conformation and double-layer conformation.

Ellipsometric Microscope ―Design and Application of a Microscope for Oblique Observation of Samples―

Ellipsometric Microscope ―Design and Application of a Microscope for Oblique Observation of Samples―

Real-time Visualization of Lubricant Films on Head Slider Using an Ellipsometric Microscope

As the recording density increased in hard disk drives (HDDs), the head disk interface (HDI) spacing has been decreased to 2-3 nm during its operation. The head slider may pick up the lubricant at this contact or near-contact HDI. Therefore, a real-time visualization of lubricant thickness distribution on a slider surface is essential to study the physical mechanisms for reducing the head disk interface spacing. A vertical-objective-based ellipsometric microscope (VEM) was presented as the effective method for real-time visualization of nm- thick lubricant films on disks with high lateral resolution. However, extinction coefficient of head slider is low, which means the intensity of reflected light may be reduced. In this report, the feasibility of VEM used for head observation is discussed, and the images of polar perfluoropolyether (PFPE) lubricant Zdol4000 applied on head slider are obtained by the current setup. It indicates that this method can be used in real-time visualization of nm-thick lubricant films on head slider.

Visualization of nanometer head slider lubricant films based on ellipsometric microscope

Visualization of nanometer head slider lubricant films based on ellipsometric microscope

基于改进椭圆偏振显微镜的纳米润滑薄膜动态观测

基于改进椭圆偏振显微镜的纳米润滑薄膜动态观测

垂直観測型エリプソメトリー顕微鏡の摺動すきま形状計測への適用

Gap measurement is essential to clarification of lubrication phenomena at nano-meter gaps; however, there are no well-established methods. We present a new method for measuring the distribution of nano-meter sliding gaps. Vertical-objective-type ellipsometric microscope (VEM) was applied to sliding gap measurements. Feasibility of the method for the nano-meter gap measurement was demonstrated.

エリプソメトリー顕微鏡を用いた磁気ヘッド上の潤滑膜観測の高精度化

エリプソメトリー顕微鏡を用いた磁気ヘッド上の潤滑膜観測の高精度化

J1640203 エリプソメトリー顕微鏡を用いた薄膜の局所的膜厚の定量化([J164-02]マイクロ・ナノ理工学:nmからmmまでの表面制御とその応用(2))

J1640203 エリプソメトリー顕微鏡を用いた薄膜の局所的膜厚の定量化([J164-02]マイクロ・ナノ理工学:nmからmmまでの表面制御とその応用(2))

Nanoscale scanning near-field ellipsometric microscopy (SNEM) imaging of heterogeneous polymers

ABSTRACTIn this study a scanning near-field ellipsometric microscope (SNEM), a hybrid device of an atomic force microscope (AFM) and an ellipsometer, is used to obtain optical images of heterogeneous polymer thin films with a resolution below the diffraction limit of light. SNEM optical images of a microphase separated PS-b-P2VP block copolymer film collected with gold coated and bare silicon AFM probe tips were compared to obtain a deeper insight into the nature of the SNEM contrast mechanism. Furthermore, intensity vs. distance curves were recorded on a PS-b-PMMA block copolymer film simultaneously during the acquisition of force-displacement curves to study the far-field contribution of the optical signal to the optical image.

Theoretical and experimental study on two-stage-imaging microscopy using ellipsometric contrast for real-time visualization of molecularly thin films

A two-stage-imaging ellipsometric-contrast microscope (TIEM) has been developed to measure the distribution of film thickness over a wide area of molecularly thin liquid films with a high lateral resolution, wide field of view, high thickness resolution, and high-speed. Moreover, this ellipsometric microscope enables us to achieve simultaneous measurements with other measurement apparatuses. We present the principle used to parallelize an object image to an imaging sensor and to reduce the incident angle entering the imaging sensor. In addition, we discuss the characteristic shape deformation of the object image due to oblique observation. The performance of the actual setup for TIEM was experimentally studied. A lateral resolution of about 1 μm was obtained by measuring the modulation transfer function of the TIEM. We also found that the shape deformation approximately agreed with that from theory. Furthermore, for molecularly thin films, we confirmed linearity between the film thickness and the light intensity measured with TIEM, which enables us to quantify the thickness of the films. TIEM can open up a new field of real-time imaging of thin films such as visualization of a liquid lubricant film under shear.

In Situ, Real Time Monitoring of Surface Transformation: Ellipsometric Microscopy Imaging of Electrografting at Microstructured Gold Surfaces

Surface chemical reactivity is imaged by combining electrochemical activation of a surface transformation process with spatiotemporal ellipsometric microscopy. An imaging ellipsometric microscope is built, allowing ellipsometric images of surfaces with a lateral resolution of ∼1 μm and a thickness sensitivity of ∼0.1 nm in air and 0.4 nm in a liquid. These performances are particularly adapted for using such optical setup as an in situ, real time chemical microscope to observe a chemical surface transformation. This microscope is tested for the monitoring of the electrochemically actuated diazonium grafting of a gold surface. Such reaction is a model system of organic material deposition on a gold surface induced by an electrochemical actuation. Using either plain or physically or chemically structured electrodes, it allows for the characterization of local phenomena associated with the electrografting process. This illustrates its potential to reveal the local (electro)chemical reactivity of surfaces.

Simultaneous Measurement of Film Deformation and Friction Force During Shearing of Molecularly Thin Lubricants

The shearing deformation of the lubricant film was measured by using two-stage imaging ellipsometric microscope (TIEM) combined with an optical-fiber-based friction force measurement method. The TIEM enables high-lateral-resolution and real-time measurements of the thickness distribution of the nanometer-thick lubricant films during shearing. By adding a relay lenses illumination system and a high-power LED light source to the TIEM, a thickness resolution of 0.14 nm was achieved. The results of an experiment using this apparatus demonstrated that the asynchronous component of the probe oscillation, which is induced by friction force between the probe and lubricant or disk and corresponds to acoustic emission avalanches in the head-disk interface of hard disk drives, can occur when the probe is in contact with the lubricant film. The time constant of replenishment of the sheared lubricant film was of the order of hundreds of microseconds, which is much shorter than the timescale of diffusion phenomena.

Ellipsomicroscopic studies of the anodic oxidation of p-type silicon in fluoride containing electrolytes during current oscillations

We report spatially resolved studies of the electrodissolution of p-type silicon in fluoride containing electrolytes in the oscillatory regime with an ellipsometric microscope. In contrast to recent findings with n-type silicon electrodes, it is demonstrated that all sustained oscillations proceed uniformly on the entire electrode. From the spatially averaged data, the oxide layer thickness oscillations could be (semi) quantitatively evaluated. Assuming a linear potential drop across the oxide, phase relations between current density, oxide layer thickness and electric field in the oxide are discussed. Again in contrast to n-type silicon, in the chosen electrolyte oscillations are only stable with a sufficiently large ohmic resistance in series to the electrode∣electrolyte interface. They emerge through a supercritical Hopf-bifurcation when increasing the external voltage at a high series resistance or increasing the series resistance at some intermediate value of the applied voltage. At larger ammonium fluoride concentrations, complex periodic, quasi periodic and deterministically chaotic oscillations were observed. Implications of the experimental findings for the mechanism of the base oscillator and the synchronization of the oscillations are inferred.

Development of Ellipsometric Microscope for High-Resolution Observation of Nanometer-Thick Lubricant Films

Real-time visualization of the nm-thick liquid lubricants is useful to clarify the lubrication phenomena using liquid thin films, for example, the lubrication for hard disk drives. In this paper, we present a method of measuing the film thickness using a vertical-objective-based ellipsometric microscope, which is a microscope based on ellipsometry that widely used for the investigation for thin films. In this method, the intensity signal can be directly converted to the thickness and the calibration can also be done by a phase shift method without any other devices. Sub-nm thickness and the sub-μm lateral resolutions were experimentally achieved for the visualization of the nm-thick lubricant films.

564 エリプソメトリー顕微鏡を用いたナノ厚さ潤滑膜の動的可視化(GS 機械材料・材料加工・潤滑)

564 エリプソメトリー顕微鏡を用いたナノ厚さ潤滑膜の動的可視化(GS 機械材料・材料加工・潤滑)

F-3 2段結像型エリプソメトリー顕微鏡による液体ナノ薄膜の動的可視化(マイクロナノ理工学)

F-3 2段結像型エリプソメトリー顕微鏡による液体ナノ薄膜の動的可視化(マイクロナノ理工学)

652 エリプソメトリー顕微鏡を用いたナノ厚さ潤滑膜の可視化(OS8-1,OS8 マイクロ・ナノ工学)

652 エリプソメトリー顕微鏡を用いたナノ厚さ潤滑膜の可視化(OS8-1,OS8 マイクロ・ナノ工学)

1410 高分解能エリプソメトリ顕微鏡によるナノ厚さ潤滑膜の動的観測(口頭講演,トピックスセッション:磁気ヘッド浮上すきま低減技術(2))

1410 高分解能エリプソメトリ顕微鏡によるナノ厚さ潤滑膜の動的観測(口頭講演,トピックスセッション:磁気ヘッド浮上すきま低減技術(2))

Measurement of thickness of molecularly thin lubricant film using ellipsometric microscopy

Controlling the kinetic behaviors of molecularly thin lubricant is a key technology for designing head-disk interfaces (HDIs) of hard disk drives (HDDs). Direct visualization of molecularly thin lubricant films is useful in investigating kinetic properties such as replenishment or retention of thin lubricant films. To meet this demand, we demonstrated that the ellipsometric microscope can provide real-time visualization with a sub-nm thickness resolution. In this paper, we present a method of measuring the thickness of the lubricant film. In this method, the phase difference between the lights reflected from the film-covered and uncovered regions of the disk is obtained from the polarizer angles; then the thickness is calculated from the phase difference. We verified the feasibility of the method theoretically and experimentally. Measurement error of less than 0.2 nm was experimentally achieved for molecularly thin lubricants. This method provides real-time and quantitative imaging of molecularly thin lubricants and can provide useful information for designing HDIs for high-density HDDs.

Direct Visualization of Molecularly Thin Lubricant Films on Magnetic Disks by Ellipsometric Microscopy With a White Light Source

We demonstrated the direct visualization of molecularly thin lubricant films on magnetic disks with a thickness resolution of 0.1 nm by using an ellipsometric microscope with a white light source. It was able to reduce the optical interference noise that arises in conventional laser-based ellipsometric microscopes and to provide a larger SNR by a factor of about 6 compared to a laser-based ellipsometric microscope. The wavelength width should be given first priority in designing a white-light-source ellipsometric microscope, and the width should be determined after considering the required coherence length and thickness resolution. Theoretical calculations indicate that a wavelength width of less than 10 nm can provide a thickness resolution of 0.1 nm. A white-light-source ellipsometric microscope can provide real-time visualization of a molecularly thin lubricant film with a thickness resolution of 0.1 nm, which is useful in investigating the kinetic behavior of molecularly thin lubricant films on magnetic disks.