Electron Beam Edge Bead Removal for Semiconductor Substrates
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Solution Overview
Problem
Conventional methods for removing edge beads from substrates during semiconductor fabrication are inefficient, particularly for materials like metal-containing photoresists, anti-reflective coatings, and polyimides, as they either require chemical solvents or light exposure, which are not effective across all materials and can lead to particulate contamination and yield loss.
Innovation Solution
A substrate processing system utilizing an electron beam to vaporize edge bead material by emitting an electron beam with specific energy and current, combined with an airflow system to collect the vaporized material, ensuring precise removal without overheating the substrate and accommodating various materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If chemical solvents or light exposure methods are used to remove edge beads, then the removal process can be performed, but it leads to particulate contamination and yield loss
Solution Approach 1:
The patent replaces chemical and optical methods with a physical electron beam-based material removal system. The electron beam interacts with the edge bead material to generate localized heat, causing vaporization and removal of the edge bead without introducing particulate contamination associated with chemical solvents or light exposure methods.
Solution Approach 2:
The patent changes the removal mechanism by using electron beam energy parameters (beam current, beam power) to control the heating and vaporization process. By adjusting these parameters, the system can selectively remove edge bead material based on its composition without affecting the underlying substrate or introducing contamination.
2Adaptability or versatility
If conventional material removal methods are used, then they work for some materials, but they are not effective for metal-containing photoresists, anti-reflective coatings, and polyimides
Solution Approach 1:
The patent creates a universal material removal system that can handle diverse materials including metal-containing photoresists, anti-reflective coatings, and polyimides. The electron beam-based system provides a single versatile solution that replaces multiple material-specific removal methods, achieving consistent effectiveness across different material compositions.
Solution Approach 2:
The patent uses adjustable electron beam parameters (energy, current, scanning speed) to adapt the removal process to different material types. This allows the same physical mechanism to effectively remove various materials by optimizing the beam interaction conditions for each material composition.
3Productivity
If high energy is used to vaporize edge bead material, then removal is effective, but it may overheat and damage the substrate
Solution Approach 1:
The patent applies heating locally to the edge bead region using a focused electron beam, rather than heating the entire substrate. The beam can be scanned across or concentrated on the peripheral edge bead area, providing localized energy input that vaporizes the edge bead material while the bulk substrate remains at safe temperatures.
Solution Approach 2:
The patent uses scanning or pulsed electron beam operation to deliver energy periodically to the edge bead region. This allows heat to dissipate between pulses or scan positions, preventing cumulative overheating of the substrate while maintaining effective material removal through repeated localized energy input.
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 electron beam system effectively removes edge beads from substrates, preventing contamination and improving yield by vaporizing materials regardless of surface reflectivity, and can be integrated into existing spin-coating processes, enhancing processing efficiency and reducing misalignment issues.
Implementation Method 1
an electron emitter adapted to emit an electron beam having an energy and a current sufficient to vaporize material in a peripheral region of the substrate
Implementation Method 2
vaporize material from the first surface of the peripheral region of the substrate
Data Source
AI summary
A substrate processing system includes a processing chamber, a substrate holder configured to hold and rotate a substrate about an axis perpendicular to a working surface of the substrate; an electron emitter adapted to emit a first electron beam directed at a first surface of a peripheral region of the substrate, the first electron beam having a first beam energy and a first beam current sufficient to vaporize material from the first surface of the peripheral region of the substrate; an airflow system configured to direct a flow of gas across the working surface of the substrate; and an exhaust system configured to collect the gas comprising the material vaporized from the peripheral region.