1. Target installation :
The most important consideration in the target installation process is to ensure a good thermal connection between the target and the sputter gun cooling stave. The target will break when installation if the warpage degree of cooling stave is server or the backing plate warpage degree is severe .,which will greatly affect the thermal conductivity between the target and the backing plate, resulting in heat dissipation failure during the sputtering process, and will eventually cause the target to crack or peel off . To ensure adequate thermal conductivity, a layer of graphite paper can be placed between the cathode stave and the target. Considering the cleanliness of the using cooling water and there might be some dirt generated during the operation of the equipment ,and the dirt might be deposited in the cathode cooling water tank . Therefore, the cathode cooling water tank needs to be inspected and cleaned when installing the target to ensure the smooth circulation of the cooling water and the inlet and outlet will not be blocked . Some equipment has a design with small gap between cathodes and anodes ,so it is necessary to ensure that there is no touching between the cathode and the anode and there is no conductor when mounting the target, otherwise a short circuit will occur. Please try to install the target according to the relevant suggestions provided .
1.1 Installation metal targets materials :
When tightening the target fixture, please first tighten a shackle by hand, then turn another shackle on the diagonal line by hand, and repeat until all the shackles are installed. Use tools to tighten
1.2 Installation ceramic targets materials :
It is not advisable to intall the ceramic target too tightly ,after tightening the screw ,we suggest to return the screw to the half circle to avoid cracking of the target due to the volume expansion after the temperature rise during the sputtering process .
2. Short circuit and tightness check
After the target is installed, it is necessary to perform short-circuit inspection and sealing inspection on the entire cathode. It is recommended to judge whether there is a short circuit in the cathode by using a resistance meter to shake the watch. After determining that there is no short circuit in the cathode, a leak check can be performed to pass water to the cathode to determine whether there is water leakage.
3.Pre-sputtering of the target
Target pre-sputtering is recommended for sputtering with pure argon to clean the surface of the target. It is recommended to increase the sputtering power slowly when the target is pre-sputtered. The power increase rate of the ceramic target is recommended to be 1.5 W/cm2. The pre-sputtering speed of the metal target can be faster than the ceramic target, and a reasonable power increase rate is 1.5 Wh/cm2. It is necessary to check the arcing condition of the target while pre-sputtering, and the pre-sputtering time is generally about 10 minutes. If there is no arcing, continue to increase the sputtering power to the set power. According to experience, the maximum sputtering power that the metal target can withstand is 10 watts/cm 2 and the ceramic target is 3 – 4 watts/cm 2 (sputtering power (RF) ≤ 100 W). In the meantime, please refer to the user system operation manual for setting the vacuum chamber pressure (Pa) during sputtering. ( from your equipment supplier ) According to experience, it should be generally ensured that the water temperature of the cooling water outlet should be lower than 35 degrees Celsius, but the most important thing is to ensure that the cooling water circulation system can work effectively. The rapid circulation of cooling water removes heat, which ensures high power and it is an important guarantee for continuous sputtering. For metal targets, it is generally recommended that the cooling water flow rate be 20 LPM and the water pressure be about 5 GMP. For ceramic targets, it is generally recommended that the water flow rate be 30 LPM and the water pressure be about 9 GMP.
4. Target and environment maintenance
In order to avoid short circuit and arcing caused by the unclean cavity during the sputtering process, it is necessary to remove the sputtered material deposited in the middle and on both sides of the sputtering track in stages, which also helps the user to continuously perform at the maximum power density of sputtering. Dark area shields, cavity walls and adjacent surfaces also need to be kept clean. When cleaning the vacuum chamber, we recommend using glass ball blasting to treat the dirty parts while using compressed air to remove the spattered residue from the surrounding area of the chamber, and then gently polishing the surface with alumina-impregnated sandpaper. After the gauze is polished, it is washed with alcohol, acetone and deionized water, and an industrial vacuum cleaner is recommended for auxiliary cleaning.
5. Continuous sputtering time should not be too long (≤40min)
