In the topic "Material Technologies", we develop processes and technologies for the production of reusable silicon and germanium growth templates and for epitaxially grown silicon and germanium wafers or films. The detachment of the epitaxial layers is made possible by the electrochemical porosification of a mother substrate. In addition to the electrochemical etching parameters, the quality of the surface of the mother substrate plays a decisive role in the quality of the end product. Both purely chemical and chemical/mechanical processes can be used for preparation. After etching the multilayer porous layer into the substrate, a thermal reorganization takes place during which the surface of the porous layer closes and a mechanical predetermined breaking point is formed.
Equipment and processes for the production of such growth templates for silicon and germanium are part of our excellent R&D infrastructure at Fraunhofer ISE. Our R&D activities cover the entire process sequence: substrate selection, surface preparation, porosification, healing and reorganization of the porous layer, epitaxial growth, surface definition, detachment of the films as well as various processes for gluing or bonding the films to cost-effective substrates. All these processes are developed with a view to achieving high throughputs and low costs while maintaining high material quality. Our customers are system manufacturers as well as precursor suppliers and users.