Plasma Processing RF Pulsing for Rapid Ion Energy Control
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Solution Overview
Problem
In plasma processing for electronic device manufacturing, there is a need to rapidly change the energy of ions directed towards the substrate support.
Innovation Solution
A plasma processing method involving continuous supply of first radio-frequency power to a lower electrode, with second radio-frequency power being supplied as pulsed or continuous power at different frequencies during specific periods to alter ion energy efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If bias radio-frequency power is used to adjust ion energy, then ion energy can be controlled, but the response speed of ion energy adjustment is slow
Solution Approach 1:
The patent applies periodic action by using pulsed radio-frequency power instead of continuous bias power. The pulsed power is applied in synchronized cycles with the main plasma-generating radio-frequency power, creating periodic modulation of ion energy. This allows rapid switching between different ion energy states (high energy during pulse, low energy between pulses) while maintaining stable average ion energy control through duty cycle adjustment, thus resolving the contradiction between fast response speed and control stability
2Productivity
If high power bias radio-frequency is applied to increase ion energy, then etching speed improves, but substrate damage increases
Solution Approach 1:
The patent uses periodic pulsed radio-frequency power to create time-varying ion energy conditions. During the pulse period, high ion energy provides strong physical sputtering for fast etching. During the non-pulse period, low ion energy reduces substrate damage and allows volatile byproducts to desorb. This periodic modulation enables high etching speed while minimizing cumulative substrate damage, resolving the contradiction between productivity and harmful effects
Solution Approach 2:
The patent applies dynamics by making ion energy dynamic rather than static. The radio-frequency power level is continuously modulated in sync with the plasma generation cycle, creating dynamic ion energy conditions that adapt throughout the processing cycle. This dynamic control allows the system to optimize etching rate during high-power phases while protecting the substrate during low-power phases, resolving the contradiction between etching speed and substrate damage
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables rapid and controlled adjustment of ion energy towards the substrate support, enhancing etching processes while minimizing damage to the substrate and chamber surfaces.
Implementation Method 1
The first radio-frequency power is continuously supplied to the lower electrode of the substrate support in the step of performing the first plasma processing and the step of performing the second plasma processing
Implementation Method 2
a radio-frequency power is supplied to excite the gas in the chamber, and plasma is generated from the gas
Data Source
AI summary
A plasma processing method includes performing a first plasma processing in a processing chamber in a first period, and performing a second plasma processing in the processing chamber during a second period continuously after the first period. In the first period and the second period, a first radio-frequency power for bias is continuously supplied to a lower electrode. A second radio-frequency power for plasma generation may be supplied as a pulsed radio-frequency power in a first partial period in each cycle of the first radio-frequency power in the first period. The second radio-frequency power may be supplied as a pulsed radio-frequency power in a second partial period in each cycle of the first radio-frequency power in the second period.