Multi-Beam Aperture Layout for Beamlet Displacement Control
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Solution Overview
Problem
Existing pattern definition devices in particle-beam processing or inspection apparatuses experience unwanted beamlet displacements due to secondary particle generation and charge accumulation at the rim portion of the aperture and opening array devices, leading to degraded pattern fidelity.
Innovation Solution
The device incorporates an aperture array device with at least two sets of apertures arranged in interlacing patterns, offset by a common displacement vector, and an opening array device with corresponding impact regions and additional apertures to form beamlets, reducing lateral beamlet displacements by equalizing local charge distributions and using a deflection array device with electrostatic deflector electrodes to adjust beam paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single set of apertures is used in the aperture array device, then the device structure is simple, but lateral beamlet displacements occur at the rim portion due to charge accumulation
Solution Approach 1:
The aperture array device is divided into multiple sets of apertures (first set, second set, and additional set) with different arrangements. The first and second sets are interlaced in the center portion, while the additional set is arranged in the rim portion. This segmentation allows different regions to serve different functions: the interlaced sets reduce charge accumulation effects in the center, while the additional set compensates for charge distribution in the rim region, thereby reducing lateral beamlet displacements and improving pattern fidelity.
Solution Approach 2:
Different sets of apertures are configured with different arrangements suited to their specific locations. The first and second sets use interlacing arrangements in the center portion where beamlet density is high, while the additional set uses a different arrangement in the rim portion where charge accumulation causes lateral displacements. This local optimization ensures that each region's aperture configuration addresses the specific challenges of that region, improving overall pattern fidelity without unnecessarily complicating the entire device.
2Manufacturing precision
If additional apertures are added at the rim portion, then lateral beamlet displacements are reduced, but the device complexity increases
Solution Approach 1:
The aperture array is segmented into functional zones: a center portion with interlaced first and second sets of apertures, and a rim portion with an additional set of apertures. This segmentation allows the additional apertures to be added only where needed (in the rim portion) to reduce lateral beamlet displacements, rather than uniformly increasing complexity across the entire device. The additional set is configured to form beamlets that compensate for charge accumulation effects specifically in the rim region.
Solution Approach 2:
The additional set of apertures is specifically configured for the rim portion where lateral beamlet displacements occur due to charge accumulation. By placing apertures only in the region where they are needed and configuring them with appropriate arrangements, the solution improves pattern fidelity locally without unnecessarily increasing device complexity in regions where it is not required.
3Ease of operation
If charged particles impinge on impact regions, then local charge distributions are formed for beam control, but lateral beamlet displacements occur at the rim due to uneven charge distribution
Solution Approach 1:
The aperture array device segments the charge distribution function across multiple sets of apertures. The first and second interlaced sets create charge distributions in the center portion, while the additional set creates charge distributions in the rim portion. This segmentation ensures that charge distributions are more evenly distributed across the entire aperture array, reducing the uneven charge accumulation that causes lateral beamlet displacements at the rim, while still maintaining the beam control function through impact regions.
Solution Approach 2:
Different sets of apertures are configured to create appropriate charge distributions in different regions. The additional set of apertures in the rim portion is specifically designed to form local charge distributions that compensate for the uneven charge accumulation problem in that region, thereby improving pattern fidelity while maintaining the beam control capability provided by impact regions.
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 layout reduces beamlet displacements at the rim portion, maintaining pattern fidelity by minimizing lateral deflections and ensuring precise beamlet positioning on the target surface.
Implementation Method 1
charged particles which impinge on impact regions form local charge distributions
Implementation Method 2
charged particles which impinge on impact regions form local charge distributions
Data Source
AI summary
The invention relates to a multi-beam pattern definition device for use in a particle-beam processing or inspection apparatus, said device being adapted to be irradiated with a beam of electrically charged particles and allow passage of the beam through a plurality of apertures thus forming a corresponding number of beamlets, said device comprising an aperture array device in which at least two sets of apertures are realized, an opening array device located downstream of the aperture array device having a plurality of openings configured for the passage of beamlets, said opening array device comprises impact regions, wherein charged impinge upon said impact regions.