IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Thin Films Wednesday Sessions
       Session TF-WeM

Paper TF-WeM6
Low Temperature Synthesis of Fully Textured Highly Oriented AlN Films by RF and Pulsed DC Reactive Sputtering

Wednesday, October 31, 2001, 10:00 am, Room 123

Session: Fundamentals of Deposition
Presenter: G.F. Iriarte, Uppsala University, Sweden
Authors: G.F. Iriarte, Uppsala University, Sweden
F. Engelmark, Uppsala University, Sweden
I.V. Katardjiev, Uppsala University, Sweden
H.P. Loebl, Philips GmbH, Germany
Correspondent: Click to Email
Textured as well as epitaxial thin AlN films are of great interest for a wide range of electro-acoustic and optoelectronic applications. Reduction of the deposition temperature is of vital importance in a number of applications due to thermal budget limitations. In this work we study systematically the influence of the process parameters on the film properties and identify the mechanisms leading to improved film quality as well as reduced deposition temperature with both RF and pulsed DC sputtering in an Ar/N@sub 2@ atmosphere. It is demonstrated that fully textured (0002) films are grown under a wide range of conditions. At the same time the FWHM of the rocking curve of the (0002) XRD peak is found to vary systematically with process conditions - depostion rate, process pressure and gas composition, substrate temperature and bias. The best films show a FWHM of 1.2@super o@. By comparing RF and pulsed DC sputtering we have identified the major mechanisms leading to the synthesis of high quality films. Thus it has been found that by far the most important factor is the arrival energy of the sputtered Al atoms which is primarily controlled by the process pressure. We report for the first time that fully textured AlN films with a FWHM of under 2@super o@ can be grown at room temperature. Other important factors are the ion and electron bombardment of the films, substrate temperature as well as gas composition, although their influence is not as dramatic. Generally, the film quality increases with temperature. Bias and electron bombardment within a certain range also lead to better films. Low Ar/N@sub 2@ ratios also result in improved film quality although the mechanisms are not fully understood.