Pattern Inspection Apparatus with Multi-Region Comparison Circuits
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Solution Overview
Problem
Current pattern inspection methods require separate scanning operations for die-to-die and die-to-database inspections, leading to prolonged inspection times when regions inspected by both methods are intermingled, as they operate independently and necessitate two setup operations.
Innovation Solution
A pattern inspection apparatus and method that utilize an optical image acquisition mechanism and multiple comparison circuits to perform both die-to-die and die-to-database inspections simultaneously by varying the number of comparison circuits for each region, allowing for efficient inspection processing even when regions for both methods are intermingled.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate scanning operations are performed for die-to-die and die-to-database inspections, then inspection accuracy is maintained, but inspection time is prolonged
Solution Approach 1:
The patent combines die-to-die inspection and die-to-database inspection into a single integrated inspection system. The inspection apparatus performs both inspection types simultaneously by dividing the inspection target into multiple regions and assigning different inspection methods to different regions in one scanning operation, thereby maintaining inspection accuracy while reducing total inspection time.
Solution Approach 2:
The inspection target is divided into multiple regions, with each region assigned to a different inspection method (die-to-die or die-to-database). This segmentation allows the system to perform both inspection types in parallel during a single scan, resolving the contradiction between maintaining accuracy and reducing time loss.
2Reliability
If two setup operations are performed for die-to-die and die-to-database inspections, then inspection completeness is ensured, but device complexity increases
Solution Approach 1:
The inspection apparatus is designed with multi-functionality to perform both die-to-die and die-to-database inspections through a single setup operation. The system includes multiple comparison circuits that can handle different inspection types, and a control unit that manages region division and inspection method assignment, thereby ensuring inspection completeness while reducing setup complexity.
Solution Approach 2:
The patent introduces a regional dimension to the inspection process, where different regions of the inspection target are assigned different inspection methods. This spatial differentiation allows both inspection types to be performed simultaneously in one setup, maintaining completeness while simplifying the operational complexity.
3Reliability
If duplicate scanning operations are performed for both inspection methods, then inspection thoroughness is maintained, but productivity decreases
Solution Approach 1:
The patent merges duplicate scanning operations into a single scanning event by performing both die-to-die and die-to-database inspections simultaneously on different regions of the same inspection target. This approach maintains thoroughness by ensuring both inspection types are performed while doubling productivity by eliminating redundant scans.
4Productivity
If the number of comparison circuits is increased for simultaneous inspections, then inspection efficiency is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by assigning different numbers of comparison circuits to different regions based on inspection requirements. Regions requiring die-to-die inspection are assigned to specific comparison circuits, while regions requiring die-to-database inspection are assigned to other circuits. This localized allocation improves overall efficiency while managing device complexity through selective resource distribution.
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 enables efficient inspection processing by allowing simultaneous execution of die-to-die and die-to-database inspections, reducing overall inspection time and eliminating the need for duplicate scanning operations.
Implementation Method 1
The target object is irradiated with a light flux from the light source through the illumination optical system. Light transmitted through the target object or reflected therefrom forms an image on a sensor through the optical system.
Implementation Method 2
Light transmitted through the target object or reflected therefrom forms an image on a sensor through the optical system.
Data Source
AI summary
A pattern inspection apparatus includes an optical image acquisition mechanism to acquire optical image data of a plurality of regions from a substrate where a plurality of figure patterns are formed, a plurality of comparison circuits each of which performs one of die-to-die inspection processing for comparing the optical image data with each other and die-to-database inspection processing for comparing the optical image data with reference image data generated from design pattern data, and an inspection circuit to individually output, for each region of the plurality of regions, the optical image data of a region concerned to comparison circuits, whose number is variably set for each region, in the plurality of comparison circuits, and to control each comparison circuit, serving as an output destination of the optical image data in the plurality of comparison circuits, to perform one of the die-to-die inspection processing and the die-to-database inspection processing.