In sputtering a gas is ionized by a direct current (DC) or radio frequency (RF) electric source. The ions are accelerated to a target and the impact sputters off atoms that are deposited on a substrate.
Edwards sputtering system is used to deposit chromium (Cr), aluminum (Al) and molybdenum (Mo) metals on 3 inch wafers using argon (Ar) gas.
Both DC and RF power sources are available for sputtering. The deposition rate is controlled by varying the applied power, and can be as high as a few um/hr with good film quality in terms of conductivity and uniformity.