Each power supply functions in its’ own unique way.
When it comes to the process of sputtering, there needs to be a consistent form of power in order to achieve the optimal rate that it requires to adequately function. There are numerous types of power supplies (RF, DC, Pulsed DC, MF AC) that are used in the process of magnetron sputtering which are discussed below. If you’re looking to determine which power supply suits your personal preference the best, these tips will aid you in the process.
Radio Frequency (RF)
RF power can essentially be used with any type of material, but it performs the best when dielectric target materials are utilized. Although the deposition rate is low, when compared to DC power, and there is significant heating due to the electron flux, it’s essentially limited to smaller substrate sized. However, don’t let this fool you into thinking that RF is less than powerful when it comes to sputtering techniques. It’s a technique that is still used often.
Direct Current (DC)
DC sputtering power is typically used with electrically conductive materials due to its low costs and ease of use. It’s one of the most common types of sputtering power supplies on the market today.
Pulsed Direct Current (Pulsed DC)
Pulsed DC is used most commonly in reactive sputtering applications where positive voltage spikes are utilized to clean the target face and eliminate the buildup of a dielectric layer that is prone to severe arcing from ion beam etching. The most common frequency ranges span from 40 to 200 KHz. This technique is known as uni-polar pulsed sputtering. There is also another approach that utilizes two adjacent magnetrons that act as both a cathode and anode (alternating frequently) to mitigate the effects of dielectric buildup, and in-turn reducing the disappearing anode effect. Most of the time you’ll find this power supply being utilized within industrial use.
Mid Frequency AC (MF AC)
MF AC power is used when the deposition of non-conductive materials is present. The process begins when two separate cathodes that are in dual configuration are used and the AC current is switched between each one of the cathodes to allow the surface to be cleaned with each end phase of the cycle. This allows for significantly less arcing due to charge build up and also eliminates the need for anode cleaning, thus leading to long-term stability for the ion beam assisted deposition process. It’s considered one of the most widely used power supplies in the systems productions industry today.
Denton Vacuum, LLC can help you find the ideal sputtering systems for your deposition needs. Visit them online for more information.