Some basics about RF sputtering
26 Jun 2020 - fubar - Sreekar Guddeti
Some basics about RF sputtering
The RF sputtering is employed to sputter insulating targets. The insulating nature of the targets like Al2O3, Mg0 adds capacitance to the the circuit thereby impeding the formation of plasma. By operating at radio frequencies typically 13.56 MHz, we can reduce the impedance of the circuit.
Now the choice of the frequency can be arbitrary. However, the Original Equipment Manufacturers(OEMs) build RF power supply units operating at 13.56 MHz. The reason for this particular choice of frequency is based on the allocation of a bandwidth of frequencies for operating industrial(I), scientific(S) and medical(M) instruments. This band is called ISM band and is centered at 13.56 MHz with a bandwidth of 14 KHz and is recommended by the ITU Radio Regulations of 2012 so that these operations do not interfere with telecommunication services.