What is the Difference between DC, IF and RF in Sputtering?

The emergence and application of sputtering technology has gone through many stages. After more than 30 years of development, magnetron sputtering technology has developed into an irreplaceable method for optical, electrical and other functional thin films.How much do you know about them?

Magnetron sputtering refers to the introduction of a magnetic field between the two poles of an external electric field. While the electrons are affected by the electric field force, they are also bound by the Lorentz magnetic force, which changes their motion trajectory from the original straight line to a cycloid, thereby increasing the probability of high-speed electrons colliding with argon molecules, which can greatly increase the degree of ionization of argon molecules, thereby reducing the working gas pressure. Under the acceleration of the high-voltage electric field, Ar ions bombard the surface of the target material, causing more atoms or molecules on the surface of the target material to break away from the original lattice and splash out of the target material to fly to the substrate, and high-speed impact and precipitation on the substrate form a thin film. Magnetron sputtering has the characteristics of high film formation rate, low sheet temperature, good film adhesion and large-area coating.

Magnetron Sputtering is Divided into DC sputtering, Medium Frequency Sputtering and Radio Frequency Sputtering：

1. DC sputtering:  using a DC electric field to accelerate gas ions to bombard the target material, so that the target atoms are sputtered out and deposited on the substrate to form a thin film. The principle of DC sputtering equipment is simple, and its speed is also fast when sputtering metals.

2. Medium frequency sputtering:  using an AC power supply with a frequency between tens of kHz and hundreds of kHz to transfer energy to the plasma through capacitive coupling or inductive coupling. The bombardment energy of the ions is higher than that of DC sputtering, which can make the deposition rate more stable and uniform, and is suitable for the preparation of high-quality films.

3. RF sputtering:  RF power is used to ionize the target material, and the plasma generated is more stable. The bombardment energy of ions is higher than that of medium frequency sputtering. All types of target materials can be sputtered, including conductive, semiconductor and insulating materials. There is almost no arcing, and the film quality is high.

Three-target magnetron sputtering instrument produced by our company is equipped with three target guns and three power supplies, one RF power supply for sputtering coating of non-conductive materials, one DC power supply for sputtering coating of conductive materials, and an optional strong magnetic target for sputtering coating of ferromagnetic materials. Compared with similar equipment, Three-target magnetron sputtering instrument has the advantages of small size and easy operation, and a wide range of materials that can be used. It can be used to prepare single-layer or multi-layer ferroelectric films, conductive films, alloy films, semiconductor films, ceramic films, dielectric films, optical films, oxide films, hard films, polytetrafluoroethylene films, etc.Three-target magnetron sputtering instrument is an ideal equipment for preparing various material films in the laboratory.