Influence of the argon flow rate on the arsenic fraction of a-GaxAs1−x sputtered at high substrate temperature

The experimental study of the chemical composition of amorphous gallium arsenide (a-GaxAs1−x) versus argon flow rate, Q, by rf sputtering, shows that the As fraction of sputtered films is controlled by the argon flow rate. At the substrate temperature, Ts=500 °C, the films are stoichiometric when deposited under the argon flow rate between 8 and 22 sccm. These observations indicate that at low argon flow rate the As fraction of films is governed only by the preferential re-sputtering of As during the film growth. In addition, a correlation between the deposition rate R, and chemical composition x was deduced from these results.