4 - Atomic layer deposition based nano-island growth

Abstract

Atomic layer deposition (ALD) is considered as a distinct type of chemical vapor deposition (CVD) where each precursor is injected into the chamber separately unlike other CVD processes. The ALD is based on a set of self-limiting surface reactions with the precursor unlike other CVD processes which are based on non-self-limiting gas phase reactions. As a result to the self-limiting deposition, ALD results in conformal coatings on flat and nanostructured substrates with high uniformity and high-precision of film thickness at the atomic scale. However, nano-island growth can be achieved in ALD under specific conditions. In this chapter, an overview and a brief background about the ALD research and process is presented in addition to the general growth mechanisms. After that, the deposition of ZnO and ZrO2 nano-islands using ALD is demonstrated. The electronic and structural properties of the islands are also studied. Finally, memory devices with nano-islands charge trapping layer are fabricated and characterized. The memory characteristics and charge emission mechanism are analyzed.