Characteristics of pulsed internal inductively coupled plasma for next generation display processing

Area of Science:

• Materials Science
• Plasma Physics
• Semiconductor Manufacturing

Background:

• Inductively coupled plasma (ICP) sources are crucial for advanced display processing.
• Optimizing plasma characteristics is essential for achieving high-quality semiconductor fabrication.
• Pulsed plasma operation offers potential benefits for controlling plasma properties.

Purpose of the Study:

• To investigate the characteristics of RF pulsed plasma in ICP sources with internal linear antennas.
• To evaluate the impact of RF pulse duty percentage on plasma uniformity and electron temperature.
• To assess the effect of pulsed plasma on SiO2 etch rate uniformity.

Main Methods:

• Utilized an ICP source equipped with internal linear antennas.
• Operated the ICP source in RF pulsed mode with varying duty percentages.
• Measured plasma parameters including electron temperature and uniformity.
• Performed SiO2 etching experiments using CF4 gas.

Main Results:

• Decreasing the RF pulse duty percentage led to a reduction in average electron temperature.
• Plasma non-uniformity improved significantly with decreasing RF pulse duty percentage.
• For a time-averaged RF power of 3 kW, plasma non-uniformity decreased from 8.4% to 6.4% when the duty percentage was reduced from 100% to 60%.
• SiO2 etch rate uniformity was enhanced, correlating with improved plasma uniformity.

Conclusions:

• RF pulsed plasma operation in ICP sources is effective for improving plasma uniformity.
• Reduced RF pulse duty percentage enhances plasma diffusion during pulse-off periods, leading to better uniformity.
• The improved plasma uniformity directly translates to enhanced etch rate uniformity for materials like SiO2, beneficial for next-generation display processing.