Multipole Aberration Corrector Conduction Inspection via Electron Dose
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conduction inspection of multipole aberration correctors is challenging due to the small openings between poles, making it difficult to perform inspections before installation in multiple beam irradiation apparatuses, leading to potential defects and the need for post-installation exchange.
Innovation Solution
A conduction inspection method and apparatus that apply a charged particle beam through multiple openings in a multipole aberration corrector, using shield electrodes and control electrodes with individually connected wirings, to measure electron inflow doses and determine conduction between electrodes, allowing for pre-installation inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multipole lenses are arranged in an array to correct aberration of multiple beams, then aberration correction capability is improved, but the opening area for beam passage becomes small making conduction inspection impossible
Solution Approach 1:
The multipole aberration corrector is divided into multiple independent lens units, each with its own control electrodes and wirings. This segmentation allows individual inspection of each unit's conduction while maintaining the overall aberration correction function through the array configuration.
2Reliability
If shield substrates are arranged above and below the substrate with multipole lenses, then aberration correction performance is improved, but conduction inspection becomes impossible as probe cannot enter the opening
Solution Approach 1:
Conduction inspection is performed before the multipole aberration corrector is installed in the electron multiple beam irradiation apparatus. The inspection apparatus is configured to access the corrector in its pre-installed state, allowing conduction verification to be completed beforehand, thus avoiding the need for post-installation inspection.
Solution Approach 2:
A dedicated inspection apparatus serves as an intermediary system that can access and inspect the multipole aberration corrector before its final installation. This intermediary inspection setup overcomes the accessibility problem by providing a separate inspection pathway that does not conflict with the final operational configuration.
3Measurement precision
If conduction inspection is performed after installing aberration corrector in inspection apparatus, then operational verification is possible, but time is lost and defective correctors cannot be identified beforehand
Solution Approach 1:
Conduction inspection is performed in advance before the multipole aberration corrector is installed in the electron multiple beam irradiation apparatus. This preliminary inspection identifies defective correctors beforehand, preventing installation of faulty components and avoiding the time loss and operational issues that would result from post-installation discovery of defects.
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
Enables effective conduction inspection of multipole aberration correctors even with small openings, facilitating pre-installation aberration correction and ensuring accurate beam alignment and pattern inspection.
Implementation Method 1
applying, in a state where a predetermined potential has been applied to each shield electrode, an inspection charged particle beam to pass through a first opening, a second opening, and a third opening
Data Source
AI summary
A conduction inspection method for a multipole aberration corrector according to one aspect of the present invention includes applying, in a state where a predetermined potential has been applied to each shield electrode, an inspection charged particle beam to pass through a first opening, a second opening, and a third opening, using a multipole aberration corrector which includes an upper-stage substrate where the first opening is formed and a shield electrode is arranged around the first opening, a middle-stage substrate where the second opening is formed, a plurality of control electrodes are disposed to be opposite each other across the second opening, and a plurality of wirings are arranged to be individually connected to one of the plurality of control electrodes which are different from each other, and a lower-stage substrate where the third opening is formed and a shield electrode is arranged around the third opening, and which corrects aberration of a correction charged particle beam passing through the first opening, the second opening, and the third opening by individually variably applying a potential to each of the plurality of control electrodes; measuring, via a wiring individually connected to each control electrode of the plurality of control electrodes in the plurality of wirings, an inflow electron dose of electrons, into each control electrode of the plurality of control electrodes, which are secondarily emitted because the inspection charged particle beam has passed through the first opening, the second opening, and the third opening and has irradiated an object disposed at the downstream side of the lower-stage substrate; and determining individually, for each control electrode, whether there is conduction between a control electrode concerned and a wiring connected to the control electrode concerned, based on a result of measuring the inflow electron dose into each control electrode.