Plasma Coil Layout for Ion Beam Etching Uniformity Control
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Solution Overview
Problem
The challenge in ion beam etching is maintaining uniformity, particularly for large areas of slanted gratings, as the etching rate varies due to the inability of the stage to self-rotate, leading to non-uniform distribution.
Innovation Solution
A uniformity adjustment apparatus and method using a radio frequency power supply, power supply matching network, uniformity adjustment capacitor component, and discharge chamber with surface and cylindrical coils, along with adjustable capacitors, to control plasma density distribution and optimize coil arrangements for precise uniformity adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the stage for carrying the grating substrate is not capable of self-rotation, then the device complexity is reduced, but the etching uniformity deteriorates due to banded distribution
Solution Approach 1:
The patent introduces a uniformity adjustment capacitor component that can be adjusted locally to compensate for the non-uniform plasma density distribution caused by the fixed stage. By adjusting the capacitance value of the capacitor component, the plasma density in different regions can be optimized to achieve uniform etching results without requiring stage rotation capability.
2Productivity
If the area of the grating substrate to be etched is large, then the productivity is improved, but the etching uniformity deteriorates due to banded distribution
Solution Approach 1:
The uniformity adjustment capacitor component allows for regional optimization of plasma density across large substrate areas. By adjusting the capacitance value, different regions of the large-area substrate can be compensated to achieve uniform etching throughout the entire processing area, maintaining both high productivity and etching uniformity.
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
Achieves uniform plasma density distribution in the discharge chamber, ensuring consistent etching results, especially for slanted gratings, by adjusting plasma density through capacitive control and coil configurations.
Implementation Method 1
A uniformity adjustment coil component includes a surface coil and a cylindrical coil... The surface coil is arranged at a bottom of the discharge chamber and the cylindrical coil is wound on an outer sidewall of the discharge chamber
Implementation Method 2
The radio frequency power supply is configured to generate a first operating voltage for controlling generation of plasma in the discharge chamber
Implementation Method 3
The uniformity adjustment capacitor component is configured to adjust a power of the surface coil and/or a power of the cylindrical coil through adjusting a capacitance of the uniformity adjustment capacitor component, to adjust a plasma density distribution in the discharge chamber
Data Source
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AI summary
The present invention provides an ion beam etching uniformity adjustment apparatus and method. A uniformity adjustment capacitor component and a uniformity adjustment coil assembly which is installed at a preset position of a discharging cavity achieve adjustment of the power of a planar coil and/or cylindrical coil in the uniformity adjustment coil assembly, finally achieving adjustment of a plasma density distribution in the discharging cavity; moreover, the arrangement of the planar coil and/or cylindrical coil at the installation position can be further optimized (for instance, giving the planar coil and/or cylindrical coil a non-centrally-symmetrical arrangement or a centrally-symmetrical arrangement), and the plasma density distribution in the discharge cavity can additionally be further precisely optimized and adjusted, so as to achieve an expected plasma density distribution in the discharge cavity, and thereby achieve ion beam etching uniformity adjustment.