Ceramic Shielding Member for Charged Particle Beam Arcing
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Solution Overview
Problem
In charged particle beam apparatuses used for semiconductor device manufacturing, the existing shielding methods are inadequate in preventing arcing between the metal plate and the specimen, which can destroy the specimen due to electrical field exposure, and may also lead to arcing between the metal plate and the column.
Innovation Solution
A shielding member with a conductive ceramic body, such as SiC, having a specific electrical resistivity range of 10^6 to 10^12 Ωcm, is positioned between the specimen and the column, electrically insulated from it, and equipped with a through hole for the particle beam, allowing for biasing and switching to manage electrical fields and reduce arcing risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal plate is inserted between the column and specimen for shielding, then the electric field is confined and arcing between column and specimen is reduced, but the metal plate itself becomes susceptible to arcing to ground which can destroy the specimen
Solution Approach 1:
The patent introduces a ceramic substrate as an intermediary shielding member between the metal plate and the specimen. This ceramic substrate has high electrical resistivity (10^6 to 10^12 Ωcm) which acts as a mediator to block electrical discharge paths while allowing the electric field to be properly confined. The ceramic material serves as a safe intermediary that does not conduct electricity like metal but still provides the necessary shielding function.
Solution Approach 2:
The patent changes the electrical resistivity parameter of the shielding material from metallic (low resistivity) to ceramic (high resistivity range of 10^6 to 10^12 Ωcm). This parameter change fundamentally alters the electrical behavior of the shielding member, preventing it from becoming a ground path while maintaining its field confinement capability. The specific resistivity range is optimized to balance insulation and field control properties.
2Device complexity
If a metal plate is used for shielding, then the structure is simple and effective, but arcing between the metal plate and specimen cannot be excluded which can destroy the specimen
Solution Approach 1:
The patent employs a composite shielding structure consisting of a ceramic substrate combined with a conductive layer. The ceramic substrate provides high resistivity to prevent arcing, while the conductive layer (with lower resistivity than the ceramic) maintains electrical field confinement. This composite material approach combines the advantages of both materials to achieve both simplicity and safety.
3Object-affected harmful factors
If the shielding member is made highly conductive to control the electric field, then field confinement is improved, but the risk of arcing increases due to higher current flow during discharge
Solution Approach 1:
The patent applies local quality by creating a layered structure where different regions have different electrical properties. The bulk ceramic substrate maintains high resistivity to limit overall current flow and reduce arcing power, while localized conductive regions or surfaces provide sufficient field confinement. This spatial variation in electrical properties allows simultaneous achievement of field control and arcing reduction.
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 ceramic shielding member effectively confines the electric field, reduces arcing power, and minimizes damage to the specimen by limiting current flow during arcing, while allowing for fast switching to discharge secondary electrons, thus protecting the specimen from electrical damage.
Implementation Method 1
a conductive substrate comprised of a material having a specific electrical resistivity in a range from about 10^6 to 10^12 Ωcm
Implementation Method 2
at least one emitter for emitting charged particles; at least one column for guiding the charged particles emitted from the emitter
Implementation Method 3
The electrode of the shielding member is connected with a voltage supply; repeatedly switching the electrode of the shielding member
Data Source
Figure 1
Figure 2A~2C
Figure 3
AI summary
A shielding member for a charged particle beam apparatus includes a conductive substrate (131); and a through hole (132) extending through the conductive substrate (131). The conductive substrate (131) is comprised of a material having a specific electrical resistivity in a range from about 106 Ωcm to about 1012 Ωcm.