Silicon epitaxy is a process in which an additional monocrystalline silicon layer is deposited on to the polished crystal surface of a silicon wafer. This process makes it possible to select the material properties independently of the polished substrate, and consequently to create wafers that have different properties in the substrate and the epitaxial layer. In many cases this is necessary for the semiconductor component’s function.
Siltronic offers silicon epitaxial wafers with diameters up to 300 mm. While 300 mm EPI wafers are primarily used in highly integrated semiconductor elements (ICs), smaller diameters are also used for power applications. In order to satisfy the various requirements, substrates and epitaxial layers are designed according to customer specifications. Siltronic also develops GaN epitaxy wafers in diameters 150 mm and 200 mm on own substrates with optimized wafer thicknesses and resistivities and GaN layer stacks optimized for Power as well as RF applications.