Multi-Beam Electron Scanning With Swathing for Faster Wafer Inspection
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Solution Overview
Problem
Conventional semiconductor wafer inspection systems using single beam scanning are inefficient due to slow scanning speeds and high costs associated with multi-column systems, which require extensive space and hardware duplication, leading to inefficiencies and increased complexity.
Innovation Solution
A multi-beam scanning system that employs an electron emitter source, a beam splitter lens array to split the illumination beam into multiple electron beams, and an electronic deflection system to deflect these beams along two axes, allowing for efficient scanning by moving the sample in a constant velocity direction, thereby optimizing the write to retrace time ratio and reducing hardware requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multi-column technology is used to increase scanning speed, then productivity is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent combines multiple electron beams into a single column structure, merging the functionality of multiple columns into one integrated system. The beam splitter divides a single electron beam into multiple beams that scan different regions simultaneously, eliminating the need for multiple separate columns and their associated hardware, thereby reducing device complexity while maintaining high productivity
Solution Approach 2:
The patent segments the scanning function by dividing a single electron beam into multiple beams using a beam splitter. Each beam independently scans a different region of the sample, allowing parallel scanning that increases productivity without requiring multiple complete column assemblies, thus avoiding the complexity and cost of multi-column systems
2Productivity
If multi-column technology is used to increase scanning speed, then productivity is improved, but the space required increases
Solution Approach 1:
The patent merges multiple scanning functions into a single column by using a beam splitter to create multiple beams from one electron source. This consolidation allows all beams to be generated and controlled from one location, dramatically reducing the space required compared to multi-column systems that would require separate columns spaced far apart, while still achieving high scanning speed through parallel beam operation
3Device complexity
If single beam scanning is used to reduce hardware cost, then device complexity is reduced, but productivity decreases
Solution Approach 1:
The patent segments the single electron beam into multiple beams using a beam splitter, allowing each beam to scan a different region of the sample simultaneously. This segmentation enables parallel scanning that increases productivity while keeping the hardware simple - only one electron column is needed, maintaining low device complexity and cost while achieving multi-beam scanning speed
Solution Approach 2:
The single electron column in the patent performs multiple scanning functions by generating multiple beams that scan different regions of the sample in parallel. This multi-functionality allows one column to do the work of multiple columns, increasing productivity while maintaining the simplicity and low cost of a single-column design
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
The multi-beam scanning system significantly enhances scanning efficiency by increasing the write to retrace time ratio, reducing hardware costs, and improving throughput, while maintaining high-resolution defect detection in semiconductor wafers.
Implementation Method 1
an electron emitter source configured to emit an illumination beam
Implementation Method 2
a beam splitter lens array configure to split the illumination beam into multiple electron beams
Implementation Method 3
an electronic deflection system configured to deflect each of the electron beams in a plurality of directions, including a first direction, along two different axes
Data Source
AI summary
A multi-beam electronics scanning system using swathing. The system includes an electron emitter source configured to emit an illumination beam. The illumination beam is split into multiple electron beams by a beam splitter lens array. The system also includes an electronic deflection system configured to deflect each of the electron beams in a plurality of directions, including a first direction, along two different axes. Last, a swathing stage is used to move a sample with a constant velocity in a second direction that is parallel to the first direction.