Multi-Beam Wafer Scanning to Cut Line Overhead
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Solution Overview
Problem
Conventional particle beam inspection systems with multiple electron beams face inefficiencies due to raster scanning techniques, which result in significant line overhead and wait times for stage movement, limiting throughput and increasing complexity in controlling multi-beam tools.
Innovation Solution
A multi-beam inspection system that configures and controls a plurality of electron beams to scan a sample simultaneously and continuously, optimizing their movement into simple repetitive motions without the need for large 'jumps' between unscanned areas, thereby reducing line overhead and improving throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If raster scanning technique is used with multiple electron beams, then the sample can be scanned systematically, but line overhead and wait times increase significantly
Solution Approach 1:
The patent divides the scanning task into multiple independent beam paths, where each beam scans a separate scan line simultaneously. This segmentation eliminates the sequential nature of raster scanning, allowing parallel processing of multiple lines and significantly reducing the time loss associated with line-by-line scanning.
Solution Approach 2:
The patent implements continuous scanning by eliminating the stop-and-go nature of traditional raster scanning. Multiple beams continuously scan different lines without waiting for previous lines to complete, maintaining constant useful action throughout the inspection process and eliminating line overhead wait times.
2Productivity
If multiple electron beams are used to increase scanning speed, then throughput improves, but system complexity increases
Solution Approach 1:
The patent merges the control of multiple electron beams into a unified system where beams are generated and coordinated through a common control architecture. This combining approach allows throughput improvement through multiple simultaneous scan lines while managing complexity through integrated control rather than independent management of each beam.
Solution Approach 2:
The patent creates a multi-beam system where a single inspection apparatus performs multiple scanning functions simultaneously through multiple beams. This universal system handles both the generation of multiple beams and their coordinated control through a single platform, improving productivity without proportionally increasing overall system complexity.
3Measurement precision
If stage movement is used to reposition unscanned areas, then the sample can be inspected completely, but wait times for stage movement increase
Solution Approach 1:
The patent performs preliminary actions by having multiple beams positioned and ready to scan different lines simultaneously. Instead of completing one line then moving the stage, the system preliminarily positions multiple beams to cover multiple lines at once, eliminating the need to wait for stage movement between scan lines.
Solution Approach 2:
The patent transitions from one-dimensional sequential line scanning to two-dimensional parallel scanning by distributing multiple beams across multiple lines simultaneously. This dimensional change allows complete sample inspection to proceed in parallel across multiple lines rather than sequentially, eliminating stage movement wait times.
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 the inspection process by minimizing line overhead and wait times, allowing for faster and more efficient scanning of semiconductor wafers, improving yield and reducing defects in IC chip production.
Implementation Method 1
a deflector system between the charged-particle source and the stage configured to split the primary beam into an array of beams
Implementation Method 2
a beam of primary electrons having a relatively high energy is decelerated to land on a sample at a relatively low landing energy and is focused to form a probe spot thereon. Due to this focused probe spot of primary electrons, secondary electrons will be generated from the surface.
Implementation Method 3
The beam configuration system is configured to provide a rotated beam configuration with a rotation angle determined based on a number of beams in a row of the array of beams
Data Source
AI summary
An improved system and method for inspection of a sample using a particle beam inspection apparatus, and more particularly, to systems and methods of scanning a sample with a plurality of charged particle beams. An improved method of scanning an area of a sample using N charged particle beams, wherein N is an integer greater than or equal to two, and wherein the area of the sample comprises a plurality of scan sections of N consecutive scan lines, includes moving the sample in a first direction. The method also includes scanning, with a first charged particle beam of the N charged particle beams, first scan lines of at least some scan sections of the plurality of scan sections moving towards a probe spot of the first charged particle beam. The method further includes scanning, with a second charged particle beam of the N charged particle beams, second scan lines of at least some scan sections of the plurality of scan sections moving towards a probe spot of the second charged particle beam.