Chapter 13 - Glancing Angle Deposition

Abstract

This chapter focuses on experimental aspects of the Glancing angle deposition (GLAD) technique – its methods and possibilities. It introduces the basic theory, and describes the canonical microstructures and apparatus required to produce GLAD films, describes advanced GLAD techniques, covering procedures, which occur before, during, and after a GLAD process. The chapter also discusses the properties of GLAD films at several length scales: single column properties, the properties of an ensemble of columns, and the ‘bulk’ properties of a GLAD film and reviews applications and devices made with GLAD films. GLAD is a highly flexible nanofabrication technique combining oblique angle deposition and precise manipulation of substrate position during deposition. By depositing at oblique angles, columnar structures arise owing to a combination of ballistic shadowing and limited surface diffusion. The resulting columns are tilted toward the incident flux direction, and can be sculpted into various morphologies: slanted and vertical posts, helices, chevrons, square spirals, and combinations thereof. GLAD can partially decouple the different length scales involved in thin film production, yielding novel materials with interesting properties. GLAD is compatible with a large number of materials, further increasing the combinatorial power of the GLAD technique. Advanced GLAD techniques may offer additional control or modification of the canonical GLAD structures. Such techniques include forced nucleation through seeding and advanced substrate motion control to combat film broadening. While GLAD has been used for many applications, the dominant use to date is in optics.