Stylus profilometry

Teague E C, Scire F E, Backer S M and Jensen S W 1982 Three-dimensional stylus profilometry Wear 82 1... 

Profilometry of softer materials, such as polymers, is also possible with SFM, and with STM if the sample is conducting. Low forces on the SFM tip allow imaging of materials whose surfaces are degraded by traditional stylus profilometry. However, when the surface is soft enough that it deforms under pressure from the SFM tip, resolution will be degraded and topography may not be representative of the true... 

Stylus profilometry is a very simple and powerful tool in CMP. Profilometry can be used to determine the surface planarity change before and after CMP. Basically, in this technique, a stylus scans across a pattern feature in contact with a wafer, while the Z motion (height) of the stylus is monitored. This Z motion signal reflects the surface topography scanned. 

AFM can be run in three different modes contact, noncontact, and tapping mode. When AFM is in the contact mode (similar to stylus profilometry), the most common problem encountered is that under ambient conditions, sample surfaces are covered by a layer of adsorbed gases consisting primarily of water vapor and nitrogen. In addition, a dielectric film can trap electrostatic charge, which can contribute to additional attractive forces between probe and sample. These problems may cause friction in probing, which will destroy the sample or distort the resulting data. 

Stylus profilometry represents by far the most heavily used of all the methods used to derive sputter rates, irrespective of the application field in SIMS. This is primarily due to its simplicity, cost effectiveness, and the speed in which accurate and precise data can be attained. 

As the name suggests, this method records the crater depth by scanning a stylus over the surface of the substrate analyzed, i.e. in much the same way that contact mode AFM is carried out (AFM is covered in Appendix A. 11.4). Stylus profilometry is applied in contact mode after the removal of the sample from the SIMS instrument. Although stylus profilometry only provides a line scan, it is capable of a depth resolution precision approaching 1 nm. An example of a typical stylus profilometry scan output is portrayed along with a top-down image of the three craters measured in Figure 5.24. Note Only one crater would typically be measured at a time. 

Figure 5.24 To the left is shown a Scanning Electron Microcopy (SEM) image of multiple SIMS craters. To the right is shown the stylus profilometry scan output (line scan). The region containing the three craters the stylus is scanned over is illustrated by the dashed line within the SEM image.

Although this method is not commonly used outside of the research environment, it does provide absolute overall sputter yield information (overall, because this includes the effects of ion implantation if apparent), a fact realized as the mass removed is measured. In addition, this can be useful in cases where neither stylus profilometry nor optical profilometry is applicable. Disadvantages associated with this method lie in the fact that this does not reveal the condition of the initial surface nor the crater base formed, both of which are important if high-depth resolution is required. Extreme care must be employed when carrying out such measurements. 

In all tests a load of 75 N was applied to the pin giving a contact pressure of 1 MPa. Stylus profilometry was used to assess the depth of the wear scar produced at four places on each track and the results averaged to determine the wear. Friction coefficients were determined by dividing the measured frictional force by the applied normal load. 

SHG Sample Preparation. The polymer samples were dissolved in spectrophotonic grade chloroform (Mallinckrodt) to produce solutions with 10% polymer by weight. Solutions were filtered (5 pm) and then spun cast onto indium tin oxide (ITO) glass substrates. Film thicknesses varied finm 2 to 6 pm ( 0.5) thick, as measured by diamond stylus profilometry. Films were carefully dried to remove any excess solvent. 

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