Selective Reticle Inspection for Exposure Throughput
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of multi-pattern reticles in semiconductor manufacturing leads to reduced throughput due to the need to inspect all pattern regions before each exposure, even if only one specific region is needed, resulting in wasted time when defects are found in non-target regions.
Innovation Solution
An exposure apparatus with an integrated inspection unit and controller that allows for selective inspection and exposure of specific pattern regions on a reticle, enabling the exposure unit to focus on the inspected region without being hindered by defects in other regions, thereby improving manufacturing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all pattern regions on a multi-pattern reticle are inspected before exposure, then the reliability of the exposure process is improved, but the productivity deteriorates due to wasted inspection time on non-target regions
Solution Approach 1:
The reticle inspection is segmented into multiple regions corresponding to different pattern regions. The inspection unit selectively inspects only the specific pattern region that will be used for the next exposure, rather than inspecting all pattern regions on the multi-pattern reticle. This segmentation allows the system to maintain reliability for the target region while improving productivity by skipping inspection of non-target regions.
Solution Approach 2:
Instead of performing complete inspection of all pattern regions on the multi-pattern reticle, the system performs partial inspection only on the specific pattern region that will be used for the next exposure. This partial action is sufficient to ensure exposure reliability while avoiding the productivity loss associated with inspecting unnecessary regions.
2Measurement precision
If complete reticle inspection is performed before each exposure, then defect detection capability is improved, but the loss of time increases due to inspection of unnecessary regions
Solution Approach 1:
The inspection system applies local quality by concentrating inspection resources and attention on the specific pattern region that will be used for the next exposure. The inspection unit is configured to inspect only this local region with high precision, rather than distributing inspection effort across all pattern regions. This ensures defect detection capability for the target region while minimizing inspection time.
Solution Approach 2:
The system performs partial inspection limited to the specific pattern region that will be used for exposure. This partial inspection action is sufficient to detect defects in the target region while significantly reducing the time lost to inspecting other pattern regions that will not be used for the current exposure.
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 approach enhances throughput by allowing the exposure process to proceed with the inspected region while deferring inspection of other regions until necessary, thus minimizing delays and optimizing the use of multi-pattern reticles.
Implementation Method 1
a pattern formed on a reticle (which can also be called a photomask or an original) is generally transferred to a substrate, such as a wafer, coated with a photosensitive material (photoresist)
Data Source
AI summary
An exposure apparatus for transferring a pattern to a substrate by exposing the substrate to light via a reticle. The exposure apparatus includes an inspection unit to inspect the reticle, an exposure unit to expose the substrate to light via the reticle inspected by the inspection unit, and a controller to control the inspection unit and the exposure unit. The controller (i) sets a partial region of the reticle, (ii) causes the inspection unit to inspect the partial region of the reticle and a region of the reticle that is different from the partial region, and (iii) causes the exposure unit to expose the substrate to light via the partial region, irrespective of a presence and an absence of an abnormality in the region that is different from the partial region, if the inspection unit finds no abnormality in the partial region.