Long-wavelength components by vapor phase epitaxy

With the advent of fiber optics and optical communications technologies, much attention has been paid to the emitter and detector components associated with these technologies(1). These semiconducting devices are small chips which have been fabricated from crystalline wafers upon which "epitaxial" layers have been deposited. (Epitaxy is the phenomenon whereby the deposited solid layer adopts the crystal structure of the substrate upon which it is deposited). The purpose of this article is to compare some of the epitaxial techniques used to "grow" or synthesize these layers and then to focus in on one of the primary techniques used to grow commercial devices: vapor phase epitaxy (VPE).