Characterization of atomic layer deposition films by x-ray scattering and atomic force microscopy

Abstract

Atomic Layer Deposition (ALD) is a thin film deposition technique that has received a lot of attention in many fields of science and industry due to its sequential, self-limiting reactions. Although it is slow method, it allows uniform, high density films with conformal depositions on 3D high aspect ratio structures. ALD allows thickness control of the film down to sub nanometre range. For more understanding and future applications, certain properties like accurate thickness, density and roughness of film is needed to get characterized.

In this work ALD deposited aluminium oxide, titanium dioxide, aluminium nitride and a nanolaminate sample are characterized by X-ray Diffraction (XRD), X-ray Reflectivity (XRR) and Atomic Force Microscopy (AFM) methods.

The density, thickness and roughness of films are measured by XRR method. Grazing Incidence X-ray Diffraction (GIXRD) is used to examine the crystal nature of the deposited films. There were no peaks found for the amorphous films. The crystallite size and phases of crystalline films are determined by this method.

AFM technique was used to see the morphology of the films. AFM gives the roughness of the films as well which was giving quiet similar results to that of roughness values found by XRR. These results give a better understanding of ALD films deposited at different temperature conditions and with different thickness values.