The document discusses different techniques for epitaxial deposition used in semiconductor thin film technology. Epitaxy involves the crystalline growth of a film on a crystalline substrate, where the film takes on the properties of the substrate. The key techniques described are liquid phase epitaxy, molecular beam epitaxy, metalorganic chemical vapor deposition, hydride vapor phase epitaxy, and sputtering. The techniques are compared in terms of their strengths, weaknesses, and applications for growing semiconductor films for electronic and optoelectronic devices.