Many quantum confined devices such as lasers and high electron mobility transistors make use of the narrow band gap and high electron mobility of InAs. The difficulty associated with the preparation of InAs has hindered the development of devices employing this material system. Few systematic studies have been conducted on InAs grown by metalorganic chemical vapour deposition (MOCVD). The majority of recent InAs research has been device orientated and only a few reports of Zn and Sn doped InAs have appeared in print. Basic material characterisation has consequently been neglected. It is the aim of this book to contribute towards a better understanding of the fundamental material characteristics and in particular to improve on the current understanding of the growth dynamics of InAs. For this purpose, InAs epitaxial layers are grown by the MOCVD technique. The emphasis is on gaining an understanding of the influence of various n- and p-type dopants on the electrical and structural properties of the material as well as on the surface morphology of the material.