Optical Path Direction Change Unit for Wafer Edge Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In photolithography processing for semiconductor devices, existing inspection systems face challenges in achieving precise images without distortion, particularly at the edges, and suffer from reduced throughput due to the need for separate edge exposure and inspection apparatuses, leading to inefficiencies in wafer processing.
Innovation Solution
A substrate processing apparatus with a holding unit, rotation driving unit, moving mechanism, exposure unit, image capturing unit, and a direction change unit using multiple reflecting mirrors to extend the optical path work distance, allowing for precise edge exposure and inspection without transferring wafers between separate apparatuses, thus improving throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the work distance of the optical path is made as long as possible to obtain precise images without distortion, then image precision is improved, but the apparatus space becomes insufficient and the configuration becomes complex
Solution Approach 1:
The patent uses multiple reflecting mirrors to change the optical path direction, extending the work distance in the vertical dimension while maintaining a compact horizontal footprint. This allows the optical path to traverse a longer distance without increasing the overall apparatus area, resolving the contradiction between image precision and apparatus space.
2Measurement precision
If separate edge exposure apparatus and inspection apparatus are used, then each apparatus can be optimized for its specific function, but the throughput of wafer processing is reduced due to transfer wait times
Solution Approach 1:
The patent combines the edge exposure apparatus and inspection apparatus into a single integrated system. The exposure unit performs edge exposure processing while the image capturing unit simultaneously or sequentially performs inspection, eliminating the need to transfer wafers between separate apparatuses and thus improving throughput without sacrificing inspection precision.
Solution Approach 2:
The holding unit is designed to serve multiple functions: it holds the wafer during edge exposure processing and also positions the wafer for inspection. This multi-functionality allows the same apparatus to perform both edge exposure and inspection tasks, reducing transfer wait times and improving overall throughput.
3Length of moving object
If the work distance is extended using multiple reflecting mirrors, then the optical path length is increased for better image quality, but the device complexity increases
Solution Approach 1:
The patent extends the optical path length by utilizing the vertical dimension through multiple reflecting mirrors arranged at different heights and angles. This approach increases the optical path length without proportionally increasing the horizontal space required, and the mirrors are integrated into the existing apparatus structure to minimize additional 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 enables precise image capture with reduced distortion and enhances processing efficiency by integrating edge exposure and inspection processes, eliminating the need for separate apparatuses and reducing wafer transfer wait times, thereby improving overall throughput.
Implementation Method 1
a first reflecting mirror reflecting light reflected upward in a vertical direction from the substrate, in a horizontal direction to the edge exposure position side
Implementation Method 2
a second reflecting mirror reflecting light from the first reflecting mirror, obliquely upward at a predetermined reflection angle to the delivery position side
Implementation Method 3
a third reflecting mirror reflecting light from the second reflecting mirror, in a horizontal direction to the edge exposure position side to transmit the light to the image capturing unit
Data Source
AI summary
A substrate processing apparatus includes: a holding unit holding a substrate; a rotation driving unit rotating the substrate held on the holding unit; a moving mechanism moving the holding unit between a delivery position and an edge exposure position; an exposure unit provided on the edge exposure position side and exposing an edge portion of a coating film above the substrate held on the holding unit; an image capturing unit provided on the edge exposure position side and above the exposure unit and capturing an image of the substrate held on the holding unit; and a direction change unit changing a direction of an optical path formed between the substrate held on the holding unit and the image capturing unit. The direction change unit includes a first reflecting mirror, a second reflecting mirror, and a third reflecting mirror.