DUV LED Array Layout for Uniform UV-Ozone Optics Cleaning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The semiconductor manufacturing industry faces challenges in maintaining cleanliness within EUV inspection systems due to contamination from hydrocarbons and gas phase H2O, leading to reflectivity loss and optical system degradation, which current cleaning methods are inadequate.
Innovation Solution
A DUV LED array with a split circuit layout and dome lenses is used to generate UV radiation in conjunction with ozone for effective cleaning of optical elements, adjusting irradiance and incident angle to ensure uniform coverage and high power output in confined spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional cleaning methods are used for optical elements in EUV inspection systems, then the cleaning process is simple, but the cleaning effectiveness is insufficient and contaminants remain on optical surfaces
Solution Approach 1:
The patent applies ozone (O3), a strong oxidant, in combination with DUV light to enhance the cleaning effectiveness of optical elements. The ozone provides accelerated oxidation that breaks down and removes contaminants more effectively than traditional cleaning methods, directly addressing the insufficient cleaning effectiveness while maintaining a manageable system complexity through chemical enhancement rather than mechanical complexity
Solution Approach 2:
The patent replaces traditional mechanical cleaning methods with a photochemical cleaning system using DUV LEDs and ozone. This substitution eliminates the need for complex mechanical cleaning mechanisms while achieving superior cleaning effectiveness through the photochemical reaction between DUV light, ozone, and contaminants on optical surfaces
2Reliability
If DUV LED array with high power output is used to increase cleaning effectiveness, then contaminants are removed more effectively, but heat generation increases and requires thermal management
Solution Approach 1:
The patent introduces a heat exchanger as an intermediary component between the DUV LED array and the optical elements being cleaned. This heat exchanger acts as a thermal management intermediary that conducts heat away from the LED array, maintaining optimal operating temperatures and enabling sustained high-power operation for effective contaminant removal without thermal damage
Solution Approach 2:
The patent implements thermal management by changing the thermal parameters of the LED operating environment through the heat exchanger. By actively controlling the temperature parameter, the system maintains the LED array at optimal operating conditions even during high-power cleaning operations, ensuring both cleaning effectiveness and device reliability
3Reliability
If uniform irradiance distribution is achieved across optical elements, then cleaning uniformity improves, but the optical system design becomes more complex
Solution Approach 1:
The patent employs dome-shaped lenses in the DUV LED array design to achieve uniform irradiance distribution across the optical elements. The curved, spherical geometry of the dome lenses naturally distributes the UV light uniformly over the treatment area, providing consistent cleaning uniformity without requiring complex optical systems with multiple lenses or mirrors
Solution Approach 2:
The dome lens design serves multiple functions simultaneously: it acts as a light distribution element for uniform irradiance, a protective cover for the LED, and a structural component of the cleaning system. This multi-functionality achieves cleaning uniformity while minimizing additional optical complexity by combining several roles into a single universal component
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 DUV LED array effectively removes contaminants from optical surfaces, maintaining reflectivity and preventing optical system degradation, while fitting into small mechanical envelopes and reducing recontamination risks.
Implementation Method 1
A DUV LED array with a split circuit layout and dome lenses is used to generate UV radiation in conjunction with ozone for effective cleaning of optical elements
Implementation Method 2
at least one dome lens disposed over one or more of the LED dies, adjusting irradiance and incident angle to ensure uniform coverage
Implementation Method 3
a heat exchanger disposed on a side of the circuit board opposite that of the LED dies
Data Source
AI summary
An LED array can include a printed circuit board having a plurality of LED dies with a split circuit layout, one or more dome lenses, and a heat exchanger on a side of the circuit board opposite that of the LED dies. The LED array can be positioned in an inspection tool configured to inspect a reticle. Light from the LED array can be used to perform UV-ozone cleaning of the optical element using the light from the LED array.