In my current experiment, I am utilizing an RF dual sputtering system to create thin films of GeSn. The system consists of a Ge target positioned on the left side and a Sn target on the right side. However, I am encountering an issue where a ring is forming around the cathode. To provide a comprehensive response, I will outline the experimental conditions in detail.
The specific conditions for the left side, where the Ge target is located, include an RF power of 60 watts. On the right side, where the Sn target is situated, the RF power is set at 20 watts. There are certain conditions that are common to both sides, which are as follows: the gas used is Ar, the gas pressure is 0.3 Torr, and the gas flow rate is 400 sccm. The distance between the target and the substrate is 60 mm, and the substrate rotation speed is 3 revolutions per minute (rpm).
Without the formation of the ring around the cathode, the Ge ratio in the thin film is observed to be high. However, when the ring appears, the Sn ratio exceeds 80%. I am seeking insights into the underlying cause of this cathode ring and any potential methods to prevent its formation.
- Badges
- Science topic