A brief review of dual-frequency capacitively coupled discharges

Capacitively coupled plasmas (CCPs) have been widely used in thin film deposition and etching in a variety of industries such as those of semi-conductor/microelectronics, flat panel displays and solar-cell panels. In all these applications, to produce uniform plasmas over large surface areas is highly desired, as it not only improves the efficiency of manufacturing but also reduces the defects of product. The dual frequency (DF) CCP had been proposed and has indeed been proven to be a rather promising way to achieve this goal with relatively low cost and great ease. During the past decades, significant progresses have been made in understanding and optimizing the DF CCP, and we provide a brief review of its present research status as well as some prospects for its future research.