EUV Mask Inspection Load-Lock Chamber Moisture Control
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Solution Overview
Problem
The challenge in the EUV mask inspection process is the risk of damage to the EUV mask due to moisture-related defects, which can lead to errors in semiconductor circuit patterns, as existing inspection methods do not effectively prevent moisture-induced oxidation of the mask's surface layers during the inspection process.
Innovation Solution
An EUV mask inspection system is developed, incorporating a load-lock chamber with a UV lamp to evaporate water molecules and a cold trap to trap them, preventing moisture from interfering with the inspection and maintaining the EUV mask's integrity by ensuring a controlled environment for both atmospheric and vacuum states, allowing for precise inspection without damaging the mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the EUV mask is inspected using existing methods, then the inspection process can be performed, but the EUV mask may be damaged due to moisture-related defects and oxidation
Solution Approach 1:
The patent applies preliminary action by performing moisture removal through UV irradiation and cold trap treatment in the load-lock chamber before the EUV mask enters the inspection chamber. This pre-treatment eliminates water molecules from the mask surface in advance, preventing oxidation damage during the subsequent inspection process without interfering with the inspection itself
Solution Approach 2:
The patent creates an inert environment by using UV irradiation to evaporate water molecules and a cold trap to capture them, effectively removing moisture from the environment surrounding the EUV mask. This establishes a controlled atmosphere that prevents oxidation while allowing the inspection to proceed
2Reliability
If a load-lock chamber with UV lamp and cold trap is added, then moisture can be effectively removed and mask damage prevented, but the system complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the inspection system into distinct functional modules: a load-lock chamber for moisture removal, an inspection chamber for defect detection, and separate subsystems for UV irradiation and cold trap operations. This modular segmentation allows each component to perform its specific function independently, reducing overall system complexity while maintaining high inspection accuracy
Solution Approach 2:
The patent uses an intermediary approach by introducing a load-lock chamber as a buffer zone between the external environment and the inspection chamber. This intermediary space handles all moisture removal operations, isolating the inspection chamber from harmful environmental factors and simplifying the overall system architecture by concentrating complexity in a dedicated intermediate module
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 system effectively removes moisture from the EUV mask, preventing oxidation and ensuring accurate inspection, thereby enhancing the reliability and accuracy of the EUV lithography process by maintaining the EUV mask's reflectance and preventing defects in the semiconductor circuit patterns.
Implementation Method 1
The UV lamp may be configured to evaporate water molecules on the EUV mask by irradiating UV light onto the EUV mask
Implementation Method 2
the cold trap may be configured to trap the water molecules evaporated from the EUV mask
Implementation Method 3
a vacuum pump
Data Source
AI summary
An EUV mask inspection system includes a mask receiving unit configured to receive a manufactured EUV mask, a main chamber configured to perform an inspection on the EUV mask, and a load-lock chamber disposed between the mask receiving unit and the main chamber. The load-lock chamber includes a mask table for loading the EUV mask, an UV lamp disposed adjacent the mask table in a first direction, a cold trap disposed adjacent the mask table in a second direction, and a vacuum pump. The first direction is a direction perpendicular to a sidewall of the mask table, and the second direction is a direction perpendicular to a top surface of the mask table. The UV lamp is configured to evaporate water molecules on the EUV mask by irradiating UV light onto the EUV mask. The cold trap is configured to trap the water molecules evaporated from the EUV mask.