Ion Pump Vibration Attenuation in Charged Particle Beam Devices

Solution Overview

Problem

In charged particle beam devices, the elongation of the lens barrel due to multiple stages and complex configurations increases the distance between the ion pump and the sample chamber, leading to increased weight and manufacturing costs, and existing solutions fail to effectively attenuate the natural vibration of the ion pump connected to the lens barrel regardless of its length.

Innovation Solution

A charged particle beam device with a support member having a viscoelastic body connected between the ion pump and the lens barrel, disposed substantially parallel to the central axis, to attenuate the natural vibration of the ion pump without the need for a large-sized support body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the lens barrel is elongated to accommodate multiple stages and complex configurations for high resolution, then the resolution capability is improved, but the distance between the ion pump and sample chamber increases leading to increased weight and manufacturing cost

Engineering Contradiction:

Improveresolution capabilityVSAvoidweight of support body

Core Design Contradiction:

Measurement precisionVSWeight of stationary object

Solution Approach 1:

The invention extracts the vibration attenuation function from the support body structure itself and implements it through a separate damping member. The damping member includes a viscoelastic sheet that is disposed between the support body and the ion pump, allowing the support body to remain compact while still achieving vibration attenuation. This separates the structural support function from the vibration attenuation function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a damping member as an intermediary element between the support body and the ion pump. This damping member includes a viscoelastic sheet that mediates the vibration transmission, absorbing vibrations before they reach the ion pump. This intermediary structure allows for effective vibration attenuation without requiring an enlarged support body.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If the lens barrel is elongated to accommodate multiple stages and complex configurations for high resolution, then the resolution capability is improved, but the manufacturing cost is increased

Engineering Contradiction:

Improveresolution capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The invention extracts the vibration attenuation function from the support body structure itself and implements it through a separate damping member. The damping member includes a viscoelastic sheet that is disposed between the support body and the ion pump, allowing the support body to remain compact while still achieving vibration attenuation. This separates the structural support function from the vibration attenuation function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The damping member includes a viscoelastic sheet made of composite or specialized material that provides effective vibration attenuation. This material-based solution is more cost-effective than designing and manufacturing a larger, more complex support body structure, thereby reducing manufacturing costs while maintaining resolution capability.

Inventive Principle:

Principle #40Composite materials

3Device complexity

If the ion pump is connected to the upper portion of the lens barrel in a cantilever manner, then the structure is simplified, but the natural vibration of the ion pump is excited by the reaction force from stage movement

Engineering Contradiction:

Improvestructure complexityVSAvoidvibration stability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The invention introduces a damping member as an intermediary element between the support body and the ion pump. This damping member includes a viscoelastic sheet that mediates the vibration transmission, absorbing vibrations before they reach the ion pump. This intermediary structure allows for effective vibration attenuation without requiring an enlarged support body.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the mechanical parameters of the connection between the ion pump and the support body by introducing a damping member with specific damping characteristics. The viscoelastic sheet provides vibration attenuation through its material properties, changing the dynamic response characteristics of the ion pump mounting without fundamentally altering the cantilever connection structure.

Inventive Principle:

Principle #35Parameter changes

4Reliability

If a vibration absorber is disposed between a frame fixed to the sample chamber and the ion pump to attenuate natural vibration, then the vibration is attenuated, but the frame becomes large-sized increasing weight and cost

Engineering Contradiction:

Improvevibration attenuationVSAvoidsize of support body

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The invention extracts the vibration attenuation function from the support body structure itself and implements it through a separate damping member. The damping member includes a viscoelastic sheet that is disposed between the support body and the ion pump, allowing the support body to remain compact while still achieving vibration attenuation. This separates the structural support function from the vibration attenuation function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The damping member includes a viscoelastic sheet that functions as a flexible damping element. This thin film or sheet structure provides effective vibration attenuation without requiring a large-sized support body, thereby maintaining a compact overall structure while achieving the desired vibration attenuation performance.

Inventive Principle:

Principle #30Flexible shells and thin films

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 allows for effective attenuation of the ion pump's natural vibration, maintaining high-resolution observation capabilities without increasing the support member's size, thus enhancing throughput and reducing manufacturing costs.

Implementation Method 1

The support member includes a viscoelastic body that is disposed substantially parallel to a central axis of the lens barrel

Methodology Applied

Scientific EffectViscoelastic damping: Viscoelasticity

Data Source

PatentUS20230139507A1Charged particle beam device

Publication Date: 2023.05.04 HITACHI HIGH TECH CORP

AI summary

The present invention provides a charged particle beam device (1) capable of attenuating intrinsic vibrations of an ion pump (104) which is connected to a lens barrel (101), regardless of the length of the lens barrel (101). A charged particle beam device (1) according to the present invention comprises: a lens barrel (101) for irradiating a sample (108) with a charged particle beam (106); an ion pump (104) which is connected to the lens barrel (101) and which evacuates the air inside the lens barrel (101); and a support member (117), one end of which is connected to the ion pump (104), and the other end of which is connected the lens barrel (101). The support member (117) includes a viscoelastic body (118) which is provided substantially parallel to the central axis (114) of the lens barrel (101).