Presentation Information
[3H03]Control of Film Structure by Dual Bipolar High-Power Pulsed Magnetron Sputtering at low gas pressures
*Kai Watanabe1, Takeo Nakano1, Suruz Mian2 (1. Department of Science and Technology, Seikei University, 2. School of Engineering, Tokai University)
A dual bipolar high-power pulsed magnetron sputtering (DB-HPPMS) system was developed to deposit films with controlled structures. Bipolar pulses were alternately applied to two sputtering targets with a half-period phase shift to achieve the high plasma potential during the discharge. It allows the ionized sputtered species to reach the grounded substrate at high energy. To enable stable discharge at low pressures, the previous one-inch sputter guns were replaced with two-inch ones. When the pulse power was applied to both targets at 200 Hz, 10% duty ratio, and 30 W average power, stable operation could be achieved down to 0.4 Pa. Cu films of 500 nm-thick were deposited at several Ar pressures for positive bias voltages of 0 and 50 V. SEM observations showed that films without bias exhibited voided surfaces and porous columns. In contrast, a 50 V substrate bias produced a flat surface and dense columnar grains at 2.0 and 3.0 Pa.