Profilometry microscopy

Scanning probe microscopy is a forefront technology that is well established for research in surface physics. STM and SFM are now emerging ftom university laboratories and gaining acceptance in several industrial markets. For topographic analysis and profilometry, the resolution and three-dimensional nature of the data is... 

F. J. Giessibl, High speed force sensors for force microscopy and profilometry utilizing a quartz tuning fork, Appl. Phys. Lett. 73(26), 3956 (1998). 

Resistance R of the patterned test area is measured by a 4-point probe and total sample height, hf, is determined by direct measurement, for example by profilometry or microscopy. 

Post-CMP topography is commonly evaluated by profilometry and atomic force microscopy (AFM). Both techniques are suitable for dishing measurements with the latter having superior resolution. Additionally, when equipped with an electrical measurement system, AFM is capable of detecting excessive nitride erosion with nanometer resolution (Fig. 12.15) [30]. Except for process control, the detailed dishing and erosion AFM data can be successfully implemented for calibration of CMP simulation tools. 

The ablation depths are measured by profilometry (optical interferometer, mechanical stylus [59], atomic force microscopy [60]) and starts sharply at the threshold fluence. Similar conclusions can be drawn from reflectivity [61] or acoustic measurements [62]. The problem with these measurements is that either single- or multi-pulse experiments are used to determine the ablation depths and threshold which might give different results. 

R. Sanctuary R. Bactavatchalou, U. Muller, W. Possart, P. Alnot, J. Kruger (2003). Acoustic profilometry within polymers as performed by Brillouin microscopy. /. Physics D Appl. Phys., 36, 2738-2742. 

Measurements of topography from optical microscopy, scanning electron microscopy (SEM), scanning tunnelling microscopy (STM), atomic force microscopy (AFM), Laser profilometry, Kelvin- and electrochemical probes. 

T. Cunningham, F.M. Serry, L.M. Ge, D. Gotthard, D.J. Dawson, Atomic force profilometry and long scan atomic force microscopy new techniques for characterization of surfaces, Sutf. Eng. 16 (4) (2000) 295-298. 

Figure 7.37. Spreading of ethylene glycol on three coated paper grades (art, silk and matt) with the same surface chemical composition. Each curve represents three different measurements at three different positions on the papers, and is perfectly reproducible. The rms roughness values of the samples depends on the scale length and the waveband analysed, but for all scales measured by atomic force microscopy and white-light profilometry increase in the order art < silk < matt (see also Figures 7.44 and 7.45 below)...

In order to understand the behavior of surfaces after surface modification, it is essential to examine their surface composition and structure in detail. A large number of techniques are available, and it is often desirable to combine several of these methods. The techniques used to monitor surface properties include scanning electron microscopy (SEM), optical profilometry, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), infrared (IR) spectroscopy, imaging ellipsometry, and water contact angle measurements. 

The thickness of the deposited layers was measured by SEM microscopy and profilometry [39]. For both methods silicon platelets were used as substrates. For SEM microscopy, the coated Si platelets were broken and such a cross-section can be obtained. Fig. 14A shows the SEM cross-section of a broken Si sample coated with carbon for 30 min. The silicon substrate is represented by the bright white part on the left of the image, while the gray shadow part represents photo-deposited carbon layer. The dependence of the carbon layer thickness on deposition time measured by SEM and by profilometry is presented in Fig. 14B. Data of both methods show a nearly linear increase of the thickness with the deposition time. 

D profiles do not, however, adequately describe 3-D properties, particularly in the ease of anisotropic surfaces. The next step in the application of the wavelength-depen-dent roughness concept will therefore be an extension to 3-D evaluation, as discussed in Section 3.5. Another frequent limitation in applications is related to the limits of lateral and/or vertical resolution and to instrumental artefacts. In comparison to the laser profilometry technique, interference microscopy, AFM and stereo-SEM are able to resolve finer structures and surface features, although — in the case of AFM — problems in ease of contacting envelope may be critical for strongly corrugated surfaces. A comparative study of different teehniques will be published separately. 

For measuring the topology of the fracture surface (i.e. roughness), direct contact profilometry, laser profilometry, or the atomic force microscopy are available (6). With the help of a coordinate system, contour maps of the fracture surface can be drawn based on roughness data or through-focus procedures for the light microscope. 

A first difficulty results from the fact that the impedance data reflect the overall state of the tested surface integrating the contributions of non-rubbed and rubbed surfaces. Such data must thus be de-convoluted in order to obtain the specific impedances of these two types of surface states. A first approach to this problem might be to use models similar to those describing the impedance of a sample undergoing a localized corrosion (Oltra Keddam, 1990). In that specific case, the overall impedance can be considered as the result of two impedances in parallel, namely the impedance of the non-rubbed surface and the one of the rubbed surface. A strict interpretation requires further an evaluation of the areas of these surfaces, e.g. by using profilometry and surface observations by light optical or scanning electron microscopy. 

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