Edge Exposure Apparatus for Semiconductor Wafer Dummy Shot Alignment
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Solution Overview
Problem
In photolithography processing for semiconductor devices, existing edge exposure apparatuses face inefficiencies due to the need for dummy shots in regions where actual exposure is not performed, leading to reduced throughput, especially when the pattern shots are not aligned parallel or perpendicular to the wafer's orientation flat or notch.
Innovation Solution
An edge exposure apparatus equipped with an imaging unit, substrate holding unit, exposure unit, and control unit that acquires array information of pattern shots from a substrate image to adjust and perform dummy shots accordingly, allowing for accurate exposure even when the pattern array is not parallel or perpendicular to the wafer's orientation features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dummy shot is performed in the exposure apparatus to expose the edge portion of the resist film, then the edge exposure is achieved, but the throughput of the exposure apparatus is reduced
Solution Approach 1:
An edge exposure apparatus is introduced as an intermediary device between the resist coating treatment and the main exposure apparatus. This separate apparatus performs dummy shots on the edge portions of wafers, allowing the main exposure apparatus to focus on productive pattern exposure without being slowed down by edge exposure operations.
Solution Approach 2:
The exposure process is segmented into two separate operations: main pattern exposure performed by the exposure apparatus, and edge exposure dummy shots performed by the dedicated edge exposure apparatus. This segmentation allows each apparatus to optimize its function without compromising the other's throughput.
2Ease of operation
If the light source is scanned based on detected orientation flat or notch position only, then the edge exposure can be performed, but the dummy shot cannot be accurately performed when pattern shots are not aligned parallel or perpendicular to the orientation flat
Solution Approach 1:
The imaging unit captures images of the wafer surface before the dummy shot operation to detect the actual array positions of pattern shots. This preliminary detection of shot array information allows the control unit to calculate accurate scanning paths for the light source, ensuring precise dummy shot alignment regardless of the pattern orientation relative to the orientation flat.
Solution Approach 2:
The system uses feedback from the imaging unit that detects the actual pattern shot array positions on the wafer. This detected information is fed back to the control unit, which then adjusts the light source scanning path accordingly, enabling accurate dummy shot performance even when patterns are arrayed at arbitrary orientations.
Data Source
AI summary
An edge exposure apparatus includes: an imaging unit that images a front surface of a substrate; a substrate holding unit; an exposure unit that exposes an edge portion of the substrate held on the substrate holding unit; a first moving mechanism that moves and rotates the substrate holding unit; a second moving mechanism that moves the exposure unit; and a control unit that controls the first moving mechanism and the second moving mechanism, wherein the first moving mechanism and the second moving mechanism are controlled so as to acquire array information of shots of a pattern on the substrate from a substrate image of a substrate, which has already been subjected to pattern exposure, imaged by the imaging unit, and expose the edge portion of the substrate, based on the acquired array information.