| abstract |
A multi-electrode plasma processing system (10) provides flexible plasma processing capabilities for semiconductor device fabrication. The plasma processing equipment (10) includes a gas showerhead assembly (52) a radio-frequency chuck (24), and screen electrode (66). The screen electrode (66) includes base (68) for positioning within process chamber (10) and is made of an insulating material such as a ceramic or teflon. A perforated screen (70) is integral to base (68) and generates a plasma from a plasma-producing gas via a radio-frequency power source (104). The screen (70) has numerous passageways (78) to allow interaction of plasma and the process chamber walls. The screen (70) surrounds showerhead assembly (52) and semiconductor wafer (22) and can influence the entire semiconductor wafer plasma processing environment (62) including the plasma density and uniformity. The circuitry (74) electrically connect screen (70) to a power source (100) or (104) to cause screen (70) electrode to affect process plasma density and distribution. Any of the plasma electrodes showerhead assembly (52), chuck (24), or screen electrode (66) may be connected to a low-frequency power source (108), a high-frequency power source (100 or 132), electrical ground (110), or may remain electrically floating (94). |