Plasma Etching Apparatus Multi-Frequency Power Control
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Solution Overview
Problem
Current semiconductor device fabrication methods face challenges in increasing the aspect ratio of channel holes on substrates during plasma etching processes, which is crucial for enhancing the integration and performance of semiconductor devices.
Innovation Solution
A plasma etching apparatus and method utilizing a combination of radio-frequency power supplies with different frequencies, where a second radio-frequency power is provided that is 3 to 5 times the first power, and a third power is provided that is less than the second, to enhance plasma concentration and acceleration, thereby increasing the aspect ratio of channel holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single radio-frequency power supply is used for plasma etching, then the process is simple, but the aspect ratio of channel holes cannot be increased beyond conventional limits
Solution Approach 1:
The single radio-frequency power supply is segmented into three separate power supplies operating at different frequencies (first, second, and third radio-frequency powers). Each power supply targets specific etching requirements: the first provides base plasma generation, the second enhances ion energy for deeper penetration, and the third maintains plasma uniformity. This segmentation resolves the contradiction by enabling high aspect ratio etching through frequency-specific control while managing complexity through modular architecture.
Solution Approach 2:
The invention changes the frequency parameter of radio-frequency power supplies to optimize etching performance. By operating three power supplies at different frequencies, the system can independently control plasma density, ion energy, and etching anisotropy. This parameter differentiation allows achieving aspect ratios greater than 70:1 by tuning each frequency to specific etching stages, resolving the limitation of single-frequency systems.
2Speed
If high radio-frequency power is applied to increase ion energy, then etching depth improves, but plasma uniformity deteriorates
Solution Approach 1:
The radio-frequency power is segmented across three different frequencies, with each frequency serving a specific function in the etching process. The higher frequency provides the necessary ion energy for deep etching, while the lower frequencies maintain plasma uniformity and stability. This segmentation allows simultaneous achievement of high ion energy and plasma uniformity that cannot be achieved with a single power supply.
Solution Approach 2:
By changing and differentiating the frequency parameters of multiple power supplies, the system can independently optimize ion energy (through higher frequency components) and plasma uniformity (through lower frequency components). This multi-parameter control resolves the trade-off between ion energy and plasma uniformity, enabling both high etching speed and stable plasma conditions.
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
The approach effectively increases the aspect ratio of channel holes to values greater than 70:1, maximizing integration and performance of semiconductor devices by optimizing plasma uniformity and ion energy distribution.
Implementation Method 1
a radio-frequency power supply that has a connection with the electrostatic chuck and provides the electrostatic chuck with a radio-frequency power to generate a plasma in the chamber
Data Source
AI summary
Disclosed are plasma etching apparatuses, plasma etching methods, and semiconductor device fabrication methods. The plasma etching apparatus comprises a chamber, an electrostatic chuck in a lower portion of the chamber, a radio-frequency power supply that has a connection with the electrostatic chuck and provides the electrostatic chuck with a radio-frequency power to generate a plasma in the chamber, and a controller that has a connection with the radio-frequency power supply and controls the radio-frequency power.