Substrate Edge Etching Using Ultra-Short Pulse Laser
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Solution Overview
Problem
During semiconductor substrate processing, foreign matters accumulate at the edges of substrates, leading to potential damage during post-processing due to thermal expansion differences and contamination risks, necessitating an effective method for rapid and precise removal.
Innovation Solution
A substrate processing apparatus incorporating a spin chuck, chemical liquid nozzles, and laser devices, where a continuous wave laser heats the substrate and chemical liquid, while a pulse wave laser rapidly etches the edge without heating, ensuring efficient removal of foreign matters from all edge portions without damaging the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional etching method is used to remove foreign matters from substrate edges, then the foreign matters can be removed, but the substrate may be damaged due to thermal expansion differences and the process is slow
Solution Approach 1:
The patent applies parameter changes by switching from conventional continuous wave laser to ultra-short pulse laser (10^-9 seconds or less), fundamentally changing the temporal parameter of laser application. This enables rapid etching of substrate edges while minimizing thermal diffusion and preventing substrate damage through controlled parameter transformation.
Solution Approach 2:
The patent employs periodic action through pulse wave laser emission with extremely short duration (10^-9 seconds or less). This periodic, pulsed delivery of energy allows the laser to etch foreign matters from substrate edges rapidly while providing cooling intervals between pulses, preventing cumulative thermal damage to the substrate.
2Productivity
If a laser beam is used to etch the substrate edge, then the etching speed increases, but the substrate may be heated and damaged
Solution Approach 1:
The patent uses periodic pulsed laser emission with ultra-short duration (10^-9 seconds or less) to deliver energy in brief bursts. This periodic action enables high etching speed while the intervals between pulses allow heat dissipation, preventing excessive substrate temperature rise and thermal damage.
Solution Approach 2:
The patent transforms the laser parameter from continuous wave to ultra-short pulse wave, changing the temporal distribution of energy. This parameter change concentrates energy delivery into extremely brief intervals, achieving rapid etching while minimizing total heat accumulation in the substrate.
3Manufacturing precision
If chemical liquid is applied to etch foreign matters, then selective etching can be achieved, but the process time increases and adsorption of etched materials onto substrate surface occurs
Solution Approach 1:
The patent replaces the chemical etching mechanism with a physical laser ablation mechanism. By using ultra-short pulse laser, the system achieves selective removal of foreign matters through direct energy absorption and material ejection, eliminating the need for chemical reactions and significantly reducing process time while maintaining precision.
Solution Approach 2:
The patent changes the fundamental mechanism from chemical reaction-based etching to laser-based physical ablation. This parameter change in the etching mechanism enables selective removal of foreign matters without the time-consuming chemical processes and avoids the side effect of etched material adsorption onto the substrate surface.
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 apparatus effectively removes foreign matters from the substrate edges, preventing damage and contamination by selectively etching specific components and reducing by-products, thereby enhancing processing efficiency and substrate integrity.
Implementation Method 1
a first laser device configured to emit a first laser beam to heat the substrate and at least one of the chemical liquid on the substrate and the deionized water on the substrate
Implementation Method 2
a second laser device configured to emit a second laser beam to etch an edge of the substrate, the second laser beam being a pulse wave
Data Source
AI summary
A substrate processing apparatus includes: a spin chuck, on which a substrate is mounted, the spin chuck rotating the substrate; At least one of a chemical liquid nozzle configured to provide a chemical liquid to a surface of the substrate and a deionzed water nozzle configured to provide a deionized water to a surface of the substrate; and a laser device configured to emit a pulse waver laser beam having a period of 10−9 seconds or less for etching an edge of the substrate.