Chapter 2 Device Applications of Strained-Layer Epitaxy

Abstract

Publisher Summary This chapter describes the device applications of strained-layer epitaxy. The most significant improvements in device performance are expected in all the applications where the strained layer is electrically and/or optically active. In these applications, the constraints on the epitaxial growth techniques and layer design are the most demanding, which are discussed in the chapter. The chapter discusses the improvements that can be achieved by using strained layers to modify heterojunction-band offsets. It discusses the molecular-beam epitaxy (MBE) growth, transistor design, and the performance of the AlGaAs/GaInAs strained-layer modulation-doped field effect transistor (MODFET), because this device structure most clearly demonstrates the advantages and potential for the use of strained layers in charge-confinement electronic semiconductor device structures. Other device structures such as heterojunction bipolar transistors (HBTs) and resonant tunneling device structures are also briefly discussed in the chapter. The improvements that can be achieved by using strained layers to modify the bandgap are discussed in detail in the chapter. Tthe chapter briefly discusses the application of strained-layer epitaxy for the development of optimized-lattice-constant epitaxy (OLE) for optimized substrate material and associated device structures.