In this chapter, silicon wafer thin film measurements are explained. In silicon MEMS, the silicon wafer provides both the substrate and the material for the active device layer. For each type of wafer, the main requirements are sufficient thickness uniformity of the substrate and of the possible device layer, as well as, a low defect density. In addition, the electrical resistivity of the wafer needs to be sufficiently close to the requirements. MEMS structures typically contain thin dielectric and conducting films. The characterization of these is often based on methods similar to those used on silicon wafers, particularly for measuring thickness, electrical resistivity, and surface quality and roughness, and these measurements are covered in this chapter. The shape of the silicon wafer can have a big impact on several fabrication processes and product yield. Ideally the wafer is a perfectly round and flat disk of uniform thickness with the edges rounded to the desired profile. In this chapter, important wafer characteristics and measurement techniques, and wafer shape parameters are also provided. Reader is directed to the many excellent reviews on measurements published elsewhere.
|Title of host publication||Handbook of Silicon Based MEMS Materials and Technologies|
|Number of pages||10|
|Publication status||Published - 1 Dec 2010|
|MoE publication type||A3 Part of a book or another research book|