Chapter 4 Lateral Patterning of Quantum Well Heterostructures by Growth on Nonplanar Substrates

Abstract

Two- and three-dimensional patterning of semiconductor heterostructures via epitaxial growth on nonplanar NP substrates offers a number of unique features. All interfaces of the resulting patterned structure are formed in situ , thus having the potential of being free from interfacial defects or contamination, a problem often encountered in other fabrication techniques involving growth interruption. The chapter discusses the specific crystalline facets that evolve during growth and the different growth and dopant incorporation rates they exhibit provide the means for lateral patterning of the band gap, doping, and refractive index. Various types of extremely narrow lateral potential wells capable of confining both electrons and holes are formed, allowing the realization of structures showing multidimensional quantum confinement. Considerable insight has been gained into the NP growth characteristics of III–V heterostructures using molecular beam epitaxy (MBE) and organometallic chemical vapor deposition (OMCVD). The two techniques exhibit significantly different growth morphologies, which can generally be attributed to the difference in both ambience and surface chemistry. One of the remarkable features of NP growth is the ability to generate laterally confined quantum structures with defect-free interfaces. A complete understanding of growth on NP substrates will increase its usefulness as a unique technique for 3D patterning of semiconductor heterostructures.