Array Region Defect Detection for Non-Integer Pixel Pitches
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Solution Overview
Problem
Current defect detection algorithms for array regions in semiconductor manufacturing require patterns to repeat in a single dimension, necessitate integer pixel pitches, and fail to account for cell-to-cell color variation, leading to inefficiencies and reduced sensitivity.
Innovation Solution
A system and method that interpolates and dynamically compensates inspection output to handle non-integer and non-uniform pitches, reducing cell-to-cell color variation by generating a cleaner difference image for improved defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If currently used array inspection algorithms require the array region to be repeating in the horizontal dimension and cell pitch to be an integer of pixels, then the inspection process is simplified, but the system cannot handle non-integer pitches and non-uniform patterns, reducing adaptability
Solution Approach 1:
The patent changes the parameter of pitch from requiring integer pixel values to accepting non-integer pitch values. The system dynamically adjusts the inspection algorithm to accommodate varying pitch values, allowing the array region to be inspected regardless of whether the pitch is an integer or non-integer multiple of pixel size.
Solution Approach 2:
The inspection system is designed to handle multiple types of array regions with different repeating dimensions (horizontal, vertical, or both). The system can inspect array regions with pitches that are integer or non-integer multiples of pixel size, making it universally applicable to various semiconductor device configurations without requiring separate inspection processes.
2Productivity
If currently used algorithms use neighboring cells to generate a reference image, then the reference image can be obtained, but cell-to-cell color variation is not taken into consideration, reducing measurement precision
Solution Approach 1:
Instead of using only a single neighboring cell or a minimal set of cells to generate the reference image, the patent uses an excessive number of neighboring cells (multiple cells in both horizontal and vertical directions). This excessive sampling allows the system to average out cell-to-cell color variations and other noise, resulting in a more accurate reference image that better represents the true pattern.
3Adaptability or versatility
If 2-pass inspection with different wafer orientations is performed to handle array regions repeating in two different dimensions, then complete inspection is achieved, but inspection time increases
Solution Approach 1:
The patent merges the functionality of multiple inspection passes into a single inspection process. By combining horizontal and vertical neighbor cell comparisons in one pass, the system can detect defects in array regions that repeat in either horizontal, vertical, or both dimensions without requiring separate inspection passes with different wafer orientations.
Data Source
AI summary
Methods and systems for detecting defects in an array region on a specimen are provided. One system includes an inspection subsystem configured for generating output responsive to patterned features formed in an array region on a specimen. The system also includes a computer subsystem configured for determining if a pitch of the patterned features in the output is an integer of pixels in a detector of the inspection subsystem that generated the output. When the pitch is not an integer of the pixels, the computer subsystem is configured for interpolating the output to generate interpolated output having a modified pitch of the patterned features in the interpolated output that is an integer of the pixels. The computer subsystem is also configured for detecting defects in the array region by applying a defect detection method to the interpolated output.