US20260045465
2026-02-12
Electricity
H01J37/32972
The plasma processing device is designed to enhance the precision of etching layered films composed of alternating silicon-oxygen and silicon-nitrogen layers. It incorporates a spectrometer to monitor luminous intensity during plasma processing, alongside control circuitry that manages etching endpoint detection. By focusing on specific wavelength ranges associated with oxygen and nitrogen, the device effectively determines the endpoint of etching processes for each layer type based on changes in luminous intensity.
Previous methods, such as those described in Patent Document 1, have addressed selective etching of silicon oxide and silicon nitride. These methods rely on detecting a decrease in luminous intensity specific to each material to signal the completion of etching. The current invention builds upon this by integrating both oxygen and nitrogen intensity measurements to improve endpoint detection accuracy for complex layered films.
The device's control circuitry acquires two key luminous intensity measurements from the spectrometer: one from an oxygen-specific wavelength range and another from a nitrogen-specific range. The etching endpoint for silicon-oxygen layers is detected when oxygen intensity decreases while nitrogen intensity increases. Conversely, the endpoint for silicon-nitrogen layers is identified when nitrogen intensity decreases and oxygen intensity increases. This dual-measurement approach allows precise control over the etching process.
The plasma processing system includes a plasma processing chamber, gas supply, power supply, ventilation system, and the spectrometer. The chamber features a substrate support and an upper electrode showerhead to facilitate gas introduction and plasma generation. The power supply part provides RF signals to generate plasma and control etching processes. The system is designed to maintain optimal conditions for precise etching through temperature adjustments and gas flow control.
The RF power supply consists of components generating source and bias RF signals, with frequencies tailored for effective plasma generation and control. The device can modulate these signals to optimize etching conditions. Additionally, a DC power supply may be used to further refine the etching process. This comprehensive setup ensures that the plasma processing device operates with high precision, catering to the intricate requirements of modern semiconductor manufacturing.