ABSTRACT
Solid-state devices are manufactured on disks of semiconducting material called wafers. These devices are three-dimensional structures made up of stacked two-dimensional layers. Each layer is manufactured by one or two of the four basic unit operations: deposition, patterning, doping, and heat treatment; see Table 11.1 for examples of each operation. The purpose of deposition is to grow a thin layer of a specific material onto the wafer surface. Patterning is the process of selective removal of the top layer (or layers) of the wafer. In the doping processes the conductivity and resistivity of the wafer surface are altered by adding specific contaminants to the exposed areas of the wafer. Finally, heat treatment raises or lowers the wafer temperature to evaporate solvents or anneal the surface [1].
