Multi-Beam Aperture Scattering Absorbing Layers Inspection

Solution Overview

Problem

Conventional multi-beam writing apparatuses face inefficiencies in inspecting beam current and focus due to the lengthy process of individually scanning each of the numerous beams, which significantly increases inspection time.

Innovation Solution

The introduction of an aperture with a scattering layer and an absorbing layer, where the scattering layer has a through-hole for one beam to pass through while scattering others, and the absorbing layer absorbs adjacent beams, allowing for the detection of beam current with high accuracy and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional inspection method scanning each beam individually is used, then measurement precision can be maintained, but inspection time becomes excessively long

Engineering Contradiction:

Improvebeam current measurement precisionVSAvoidinspection time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The aperture member is divided into multiple regions corresponding to different beam positions, with each region containing absorption holes of specific sizes. This segmentation allows simultaneous measurement of multiple beam currents through their respective absorption holes, enabling parallel inspection of approximately 260,000 beams without sequential scanning, thus dramatically reducing inspection time while maintaining measurement precision through dedicated measurement holes for each beam.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple beam measurement functions are merged into a single aperture member structure. The aperture member simultaneously performs beam current measurement for multiple beams by providing corresponding absorption holes and measurement regions for each beam, combining what would otherwise require multiple separate measurement systems or sequential operations into one integrated component.

Inventive Principle:

Principle #5Merging (Combining)

2Productivity

If aperture size is increased to accommodate multiple beams, then all beams can be inspected simultaneously, but beam current measurement precision deteriorates due to signal mixing

Engineering Contradiction:

Improveinspection throughputVSAvoidbeam current measurement precision

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The aperture member is divided into multiple regions corresponding to different beam positions, with each region containing absorption holes of specific sizes. This segmentation allows simultaneous measurement of multiple beam currents through their respective absorption holes, enabling parallel inspection of approximately 260,000 beams without sequential scanning, thus dramatically reducing inspection time while maintaining measurement precision through dedicated measurement holes for each beam.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the aperture member have locally optimized properties: each region contains absorption holes with sizes specifically tailored to the intensity characteristics of corresponding beams. This local quality optimization ensures that each beam's current measurement is performed with appropriate hole dimensions, preventing signal mixing while enabling simultaneous measurement of all beams across the multi-beam system.

Inventive Principle:

Principle #3Local quality

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 configuration enables rapid and accurate inspection of each beam, improving the throughput by allowing only one beam to pass through while scattering and absorbing adjacent beams, thus reducing inspection time and enhancing ON/OFF control precision.

Implementation Method 1

a scattering layer that is provided with a through-hole through which the one beam passes, and by which the other beams are scattered

Methodology Applied

Scientific EffectScattering: Scattering

Implementation Method 2

an absorbing layer that is provided with an opening having a diameter greater than the diameter of the through-hole and that absorbs at least some of the beams entering it

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentUS10283316B2Aperture for inspecting multi beam, beam inspection apparatus for multi beam, and multi charged particle beam writing apparatus

Publication Date: 2019.05.07 NUFLARE TECH INC

AI summary

In one embodiment, an aperture for inspecting a multi-beam allows passage of one beam among multi-beams applied in a multi-beam writing apparatus. The aperture includes a scattering layer that is provided with a through-hole through which the one beam passes, and by which the other beams are scattered, and an absorbing layer that is provided with an opening having a diameter greater than the diameter of the through-hole and that absorbs at least some of the beams entering it.