Pulsed plasma high aspect ratio dielectric process
AssigneeApplied Materials, Inc.
InventorsAnkur Agarwal, Kenneth S. Collins, Shahid Rauf, Kartik Ramaswamy, Thorsten B. Lill
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Abstract
Radial distribution of etch rate is controlled by controlling the respective duty cycles of pulsed VHF source power applied to the ceiling and pulsed HF or MF bias power on the workpiece. Net average electrical charging of the workpiece is controlled by providing an electronegative process gas and controlling the voltage of a positive DC pulse on the workpiece applied during pulse off times of the pulsed VHF source power.
Claims9
A method of processing a workpiece supported on a workpiece support facing a ceiling in a reactor chamber, comprising:
- introducing into the chamber a polymerizing etch gas, an electronegative gas and an oxidizer gas;
- applying source power in the VHF range to the ceiling and applying bias power in the HF or MF range to the wafer support;
- pulsing said source power and pulsing said bias power, while establishing a phase lag between source and bias power pulses;
- applying a positive D.C. pulse to the workpiece support and/or a negative D.C. pulse to the ceiling during the pulse off time of the source power;
- adjusting an average accumulation of electric charge on the workpiece by adjusting the voltage of the D.C. pulse;
- adjusting the etch rate by adjusting the phase lag between the pulses of the source and bias power;
- adjusting etch rate distribution by adjusting the pulse duty cycles of the VHF source power and of the RF bias power relative to one another.
A method of processing a workpiece supported on a workpiece support facing a ceiling in a reactor chamber, comprising:
- introducing into the chamber a polymerizing etch gas, an electronegative gas and an oxidizer gas;
- applying source power in the VHF range to the ceiling and applying bias power in the HF or MF range to the wafer support;
- pulsing said source power and pulsing said bias power, while establishing respective pulse duty cycles of source power pulses and bias power pulses;
- applying a positive D.C. pulse to the workpiece support and/or a negative D.C. pulse to the ceiling during the pulse off time of the source power;
- adjusting an average accumulation of electric charge on the workpiece by adjusting the voltage of the D.C. pulse;
- adjusting the etch rate distribution between a center high distribution and an edge high distribution by adjusting the duty cycles of said source power and bias power relative to one another.
Dependencies are inferred from the claim text.