Electrostatic Chuck Structure Balancing RF Permeability and Etch Uniformity
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Solution Overview
Problem
In plasma etching apparatuses, the uniformity of the etching rate and direction on semiconductor wafers is compromised due to non-uniform electric field intensity and direction, leading to increased costs and reduced high-frequency permeability of electrostatic chuck devices with multiple bias distribution control electrodes.
Innovation Solution
An electrostatic chuck device with a recess and protrusion on the adhesive layer, a dielectric layer, and strategically placed electrodes connected to high-frequency power sources through matching boxes, which includes capacitors and coils, to optimize the sheet resistance and dielectric constant for improved uniformity and reduced thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple bias distribution control electrodes are installed in the electrostatic chuck part, then the uniformity of etching rate and direction is improved, but the thickness of the electrostatic chuck part increases and high-frequency permeability is reduced
Solution Approach 1:
The patent extracts the bias distribution control function from the electrostatic chuck part by providing the control electrode in the stage instead. This allows the electrostatic chuck part to maintain reduced thickness while still achieving uniform etching through the control electrode's high-frequency voltage application.
Solution Approach 2:
The patent combines the electrostatic attraction function (first electrode) and bias distribution control function (second electrode) into a single integrated electrostatic chuck device structure, where both electrodes work together to achieve wafer attraction and etching uniformity without increasing overall thickness.
2Manufacturing precision
If multiple bias distribution control electrodes and power sources are installed, then the uniformity of etching rate and direction is improved, but the apparatus cost increases
Solution Approach 1:
The control electrode in the stage serves multiple functions: it acts as both an electrostatic attraction electrode for wafer holding and a bias distribution control electrode for etching uniformity. This multi-functionality reduces the need for separate components and power sources, thereby lowering apparatus cost.
Solution Approach 2:
The patent merges the control electrode functions into a single electrode structure in the stage, eliminating the need for multiple separate bias distribution control electrodes and their associated power sources, thus reducing system complexity and cost.
3Force
If the sheet resistance value of the first electrode is reduced to improve electrostatic attraction, then the attraction characteristics are improved, but high-frequency permeability is reduced
Solution Approach 1:
The patent specifies an optimal sheet resistance range (1.0Ω/□ to 1.0×10^10Ω/□) for the first electrode that balances electrostatic attraction force and high-frequency permeability. This parameter optimization allows the electrode to provide sufficient attraction while maintaining adequate high-frequency signal transmission for uniform etching.
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 solution effectively reduces non-uniformity of etching on the wafer surface, maintains good attraction characteristics, and enhances the high-frequency permeability of the electrostatic chuck device, thereby improving the plasma etching process.
Implementation Method 1
an electrostatic chuck part having a sample placing surface on which a sample is placed and having a first electrode for electrostatic attraction
Implementation Method 2
a cooling base part placed on a side opposite to the sample placing surface with respect to the electrostatic chuck part to cool the electrostatic chuck part
Implementation Method 3
an adhesive layer that bonds the electrostatic chuck part and the cooling base part together
Data Source
AI summary
An electrostatic chuck device includes: an electrostatic chuck part having a sample placing surface on which a sample is placed and having a first electrode for electrostatic attraction; a cooling base part placed on a side opposite to the sample placing surface with respect to the electrostatic chuck part to cool the electrostatic chuck part; and an adhesive layer that bonds the electrostatic chuck part and the cooling base part together, in which the electrostatic chuck part has a recess and protrusion on the adhesive layer side, and a sheet resistance value of the first electrode is higher than 1.0Ω/□ and lower than 1.0×1010Ω/□.