Spiral RF Coil Jig Layout for Uniform Plasma Etching
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Solution Overview
Problem
The uneven distribution of plasma caused by variable gaps between adjacent coil segments of a spiral-shaped RF coil in a plasma processing tool leads to non-uniform etch rates, resulting in incomplete removal of oxide layers and poor electrical contact between deposited metal and underlying layers, which can cause voltage breakdown.
Innovation Solution
A movable jig is installed in the RF resonator to maintain a fixed gap between adjacent coil segments of the spiral-shaped RF coil, ensuring uniform plasma distribution and consistent etch rates across the wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a spiral-shaped RF coil is used to generate plasma, then plasma generation is achieved, but variable gaps between adjacent coil segments cause uneven plasma distribution
Solution Approach 1:
The RF coil is divided into multiple discrete coil segments that can be independently positioned and adjusted, allowing each segment to be precisely aligned to maintain consistent gaps and achieve uniform plasma distribution across the processing chamber
Solution Approach 2:
A positioning mechanism or fixture is introduced as an intermediary component between the coil segments to maintain precise and consistent spacing, ensuring uniform plasma generation without requiring direct manual alignment of each segment
2Reliability
If sputter etching is performed to remove native oxide layer, then electrical contact is improved, but incomplete removal leads to poor contact and voltage breakdown
Solution Approach 1:
The sputter etching process parameters are made dynamic and adjustable, allowing optimization of ion energy, gas flow rates, and processing time to achieve complete oxide layer removal while maintaining control over the etching depth and preventing damage to underlying layers
Solution Approach 2:
Process parameters such as RF power, pressure, and gas composition are varied during the sputter etching process to enhance oxide layer removal efficiency and ensure complete clearance, thereby improving electrical contact reliability between deposited metal and substrate
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 improves plasma uniformity, allowing complete removal of oxide layers and enhances electrical contact between deposited metal and underlying layers, preventing voltage breakdown.
Implementation Method 1
a radio frequency (RF) coil disposed within a resonator housing... the RF coil allows control of the radial ion distribution and density in the chamber body so as to improve plasma uniformity
Implementation Method 2
The sputter etching process may, for example, remove a native oxide layer from the surface of a metal layer
Implementation Method 3
a gas energizer to energize the process gas... the electrical field used to dissociate the process gas to form the plasma
Data Source
AI summary
The method includes moving a movable jig along an arc-shaped path to position a plurality of coil segments of a spiral-shaped radio frequency (RF) coil within respective first confining slots of the movable jig, wherein the RF coil is disposed within an RF resonator positioned above a chamber body of a plasma processing tool, and wherein regions of the RF coil are secured by a fixed jig mounted to the RF resonator, the fixed jig comprising a plurality of second confining slots through which corresponding coil segments of the RF coil extend; and applying a RF power to the spiral-shaped RF coil to generate plasma within the chamber body.