Evanescent microwave microscope: a new nondestructive material evaluation tool with very high resolutions - Part 2

摘要

The next image (figure 11) shows the photo and EMP image of a pattern of Indium Tin Oxide (ITO). The conducting but transparent ITO layer is used in liquid crystal displays (LCD) to apply electric fields the liquid crystal to turn on different display characters. The layer of conducting ITO is difficult to see with the naked eye. In fact, the photograph of the pattern shown in figure 11, a is enhanced by stamping the ITO patterned glass onto a red die pad in order to bring out the features. The EMP easily detects the different conductivity strengths between the glass and the ITO. These images also open another area of application for the EMP, namely its use in detecting the thickness and conductivity uniformity of ITO and the other related transparent conductors. One of the objectives of this article is to determine the ability of the improved EMP to characterize semiconductors and superconductors. More specifically, the objective is to determine if the EMP has the potential to detect grain boundaries in these two types of material. Figure 12 shows a photograph and EMP image of polycrystalline silicon. The grain boundaries are quit large, and they are on the order of 10 μm to 100 μm. They were the initial images taken in order to attain how easy the EMP can detect these types of boundaries.