High rate sputtering deposition of nickel using dc magnetron mode

High rate sputtering of nickel using dc planar magnetron was successfully developed in East Fishkill for high throughput requirement. Rates in excess of 10 kA/min from targets up to 3/8 in. thick were achieved. Magnetic field strength was found to be the key parameter in depositing nickel at high rates, which has not been very successful in the coating industry. A minimal or sufficient magnetic field strength (mfs) about 300 G at Ni target surface is crucial in forming a stable plasma in dc magnetron sputtering. This minimal mfs can be generated with a strong magnet in the cathode assembly. Upon reaching this mfs, the I–V characteristics in Ni sputtering process follow the normal I=KVⁿ relationship of dc planar magnetron sputtering. Nickel target thickness ranging from 1/8 to 3/8 in. with magnetic field strength ranging from 300 to 800 G were investigated in developing this process. The process can only be controlled well with a fine mfs adjustment. The sputtering equipment for magnetic material deposition must contain an adjustment mechanism in its cathode design in order to control mfs. Nickel film quality also seems to be affected by mfs due to the electron heating of the substrate and low angle incident atoms. A desired quality film of magnetic material such as Ni can be achieved with an optimal sputtering process that has a constant magnetic field strength at the target surface.