Plasma Etching Sequence Using RF Pulses and Negative DC Bias
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Solution Overview
Problem
Current plasma processing methods face inefficiencies in substrate etching due to power consumption and plasma reflection, particularly in the generation and utilization of ions for processing.
Innovation Solution
A plasma processing method that alternates between supplying radio frequency power and applying a negative direct-current voltage to a substrate support, where the power is stopped and the voltage is applied separately to generate ions from secondary electrons, optimizing ion generation and etching efficiency without power reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radio frequency power is continuously supplied to generate plasma, then plasma generation is maintained, but power consumption increases and plasma reflection occurs
Solution Approach 1:
The patent applies periodic pulsed radio frequency power instead of continuous power supply. The power is supplied in pulses with specific duty cycles, creating periodic plasma generation that maintains plasma stability while reducing overall power consumption and preventing plasma reflection issues associated with continuous high-power operation
2Productivity
If negative direct-current voltage is applied to generate ions, then ion generation efficiency improves, but processing time increases due to separate application periods
Solution Approach 1:
The patent merges the radio frequency power supply and negative direct-current voltage application into a single integrated processing step. Both the RF power and DC voltage are applied simultaneously during the same time period, allowing ion generation and plasma processing to occur concurrently rather than in separate sequential steps, thereby improving productivity without increasing processing time
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
This method enhances etching efficiency while reducing power consumption by generating ions effectively through secondary electrons, improving processing outcomes in plasma processing.
Implementation Method 1
The radio frequency power source supplies radio frequency power in order to generate plasma from gas in the chamber
Implementation Method 2
the negative direct-current voltage is set to generate ions in the chamber by secondary electrons that are emitted by causing ions in the chamber to collide with a substrate on the substrate support
Data Source
AI summary
A disclosed plasma processing method includes generating plasma in a chamber of a plasma processing apparatus by supplying radio frequency power from a radio frequency power source in a first period. The plasma processing method further includes stopping supply of the radio frequency power from the radio frequency power source in a second period following the first period. The plasma processing method further includes applying a negative direct-current voltage from a bias power source to a substrate support in a third period following the second period. In the third period, the radio frequency power is not supplied. In the third period, the negative direct-current voltage is set to generate ions in a chamber by secondary electrons that are emitted by causing ions in the chamber to collide with a substrate.