Extraordinary deposition rate of diamond-like carbon film using HIPIMS technology

High-power impulse magnetron sputtering (HIPIMS) technologies have great potential for material processing and surface modification of substrates. A diamond-like carbon (DLC) film is deposited using HIPIMS technology varying source voltage, pulse duration, and repetition rate. An extraordinary increase in the deposition rate is found. The deposition rate is 2.6 times greater than that expected on the basis of the proportional relationship between the deposition rate and the consumed power in the plasma lower than 40 kW. When the repetition rate is varied, the deposition rate increases proportionally with the repetition rate less than 400 Hz, while the deposition rate at 1500 Hz is a factor of 1.3 times greater than that expected by the proportional relationship. The high deposition rate under these conditions may originate from the heat generated by the increased power consumption, which may be enough to volatilize the metal component according to its vapor pressure. The density of the carbon species emitted by this heating is estimated to be on the order of 1012 cm− 3. Because of the significant increase in the deposition rate, the ion current density at the substrate increases under identical power consumption, which gives an identical sputtering yield. Therefore, an additional factor to the magnetron sputtering may cause the significant increase in the deposition rate.

► DLC film is deposited by high-power impulse magnetron sputtering.
► Power over 50 kW, pulse over 120 μs gives an extraordinarily high deposition rate.
► Excess power input may raise the target temperature.
► Vapor pressure from high target temperature is related to high deposition rate.