Handbook of Silicon Based MEMS Materials and Technologies

Chapter Twenty Six. Atomic Layer Deposition in MEMS Technology

26.1. Atomic Layer Deposition: An Introduction

Atomic layer deposition (ALD) belongs to the general class of chemical vapor deposition (CVD) methods, and it can be defined as “a film deposition technique that is based on the sequential use of self-terminating gas–solid reactions” [1]. ALD is known for its ability to deposit conformal inorganic material layers on complex three-dimensional substrates and also for its subnanometer scale precision and reproducibility. The systematic use of the self-terminating reaction chemistry in the growth process leads to the unparalleled nanoscale control of ALD films, illustrated for example by the conformal ALD-Al²O³ layer grown inside a micromachined ...