Excimer Laser Discharge Chamber Electrode Erosion Mitigation
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Solution Overview
Problem
Excimer laser discharge chamber electrodes in deep ultraviolet photolithographic manufacturing processes face wear and erosion issues, leading to reduced chamber lifetime, despite existing materials and designs aimed at extending their lifespan.
Innovation Solution
The design incorporates a discharge chamber with a specific arrangement of conductive elements and capacitors, including multiple rows of capacitors with varying spacings and capacitance values, symmetrically positioned to optimize the electrical discharge and reduce wear, and the use of materials that do not exhibit significant erosion, along with electrical isolation of the electrode ends to maintain performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional electrode materials (brass alloys) are used, then the chamber can be manufactured with standard materials, but the electrode suffers from fluoridation and erosion, reducing chamber lifetime
Solution Approach 1:
The patent changes the material parameter of the anode from traditional fluoridation-prone alloys to fluorinated polymer materials. This parameter change fundamentally alters the chemical interaction between the electrode and the discharge environment, preventing erosion and extending chamber lifetime while maintaining electrical functionality.
2Reliability
If the electrode gap dimensions are increased to reduce current density, then electrode wear is reduced, but the discharge efficiency and laser output decrease
Solution Approach 1:
The patent applies local quality by creating non-uniform current density distribution through strategically positioned conductive elements. The varying spacing of conductive elements along the electrode gap creates regions of different electrical activity, allowing optimal balance between reducing peak current density (protecting electrodes) and maintaining sufficient discharge efficiency (preserving laser output).
3Power
If conductive elements are added to tune discharge performance, then discharge efficiency is optimized, but the device complexity increases
Solution Approach 1:
The patent segments the electrode structure by adding discrete conductive elements (such as metal strips or wires) positioned at specific locations along the electrode gap. These segmented conductive elements create localized electric field modifications that tune discharge performance without requiring complete redesign of the entire electrode system, thus optimizing power while controlling complexity.
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 configuration enhances the discharge efficiency and extends the useful lifetime of the discharge chamber by optimizing the electrical tuning and component placement, leading to improved performance and reduced erosion, thus supporting more precise and longer-lasting photolithographic processes.
Implementation Method 1
pulsed capacitive discharges in an Ar—F2 gas mix to generate 193 nm laser light
Implementation Method 2
The electrodes are typically made of alloys such as brass, which inevitably fluoridates and erodes in the discharge
Implementation Method 3
DUV excimer laser chambers use pulsed capacitive discharges in an Ar—F2 gas mix to generate 193 nm laser light
Implementation Method 4
Excimer lasers are used to generate light in the deep ultraviolet (DUV) portion of the spectrum
Data Source
AI summary
Disclosed is a laser discharge chamber in which useful lifetime is extended by local electrical tuning using one or a combination of design of the chamber internal geometry, placement and distribution of components within the chamber such as electrodes, current returns, and capacitors, and selective electrical isolation of portions of the components.