Ion Beam Irradiation Apparatus Electrode Design

Solution Overview

Problem

The complexity and cost of the drive mechanism for movable Faraday cups in ion beam irradiation apparatuses are increased by the incorporation of suppressor electrodes, while omitting them leads to measurement errors due to unrepelled secondary electrons.

Innovation Solution

A first electrode is positioned upstream of the beam current measuring device to serve as both a suppressor electrode for repelling secondary electrons and a beam optical element, eliminating the need for a suppressor electrode within the movable beam current measuring device and simplifying the drive mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a suppressor electrode is incorporated in the movable Faraday cup, then measurement precision is improved by repelling secondary electrons, but device complexity increases due to complicated drive mechanism and electric line routing

Engineering Contradiction:

Improvebeam current measurement precisionVSAvoiddrive mechanism complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The suppressor electrode function is extracted from the movable beam current measuring device and relocated to a fixed electrode positioned upstream in the beam transport channel. This extraction eliminates the need to incorporate suppressor electrodes within the movable Faraday cup, thereby simplifying its drive mechanism and electric line routing while maintaining the secondary electron repelling function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The fixed electrode upstream of the beam current measuring device is designed to serve multiple functions: it acts as a suppressor electrode to repel secondary electrons from the movable Faraday cup, and simultaneously functions as a beam optical element for ion beam transport and focusing. This multi-functionality reduces the overall number of components and simplifies the system architecture.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If a suppressor electrode is incorporated in the movable Faraday cup, then measurement precision is improved, but manufacturing cost increases due to additional components and complex assembly

Engineering Contradiction:

Improvebeam current measurement precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The suppressor electrode function is extracted from the movable beam current measuring device and relocated to a fixed electrode positioned upstream in the beam transport channel. This extraction eliminates the need to incorporate suppressor electrodes within the movable Faraday cup, thereby simplifying its drive mechanism and electric line routing while maintaining the secondary electron repelling function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The fixed electrode upstream of the beam current measuring device is designed to serve multiple functions: it acts as a suppressor electrode to repel secondary electrons from the movable Faraday cup, and simultaneously functions as a beam optical element for ion beam transport and focusing. This multi-functionality reduces the overall number of components and simplifies the system architecture.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If the suppressor electrode is omitted from the movable beam current measuring device, then device complexity is reduced, but measurement precision deteriorates due to unrepelled secondary electrons

Engineering Contradiction:

Improvedrive mechanism complexityVSAvoidbeam current measurement precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

A fixed electrode is introduced as an intermediary element positioned upstream of the beam current measuring device. This intermediary electrode repels secondary electrons generated from the movable Faraday cup before they can reach the measurement region, thereby maintaining measurement precision without requiring the movable device to incorporate its own suppressor electrode.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively repels secondary electrons back to the beam current measuring device, preventing measurement errors and simplifying the drive mechanism, thereby reducing costs and enhancing operational efficiency.

Implementation Method 1

a first electrode fixedly disposed immediately upstream of the beam current measuring device... the first electrode being configured to serve both as a suppressor electrode for repelling secondary electrons released from the beam current measuring device

Methodology Applied

Scientific EffectElectrostatic force: Electrostatics

Implementation Method 2

a mass analyzing electromagnet provided downstream of the extraction electrode system

Methodology Applied

Scientific EffectMagnetic force: Lorentz Force

Data Source

PatentUS10714302B2Ion beam irradiation apparatus

Publication Date: 2020.07.14 NISSIN ION EQUIPMENT CO LTD

AI summary

An apparatus is provided. The apparatus includes a beam current measuring device and a first electrode. The beam current measuring device is retractably movable into an ion beam trajectory so as to measure an ion beam current. The first electrode is disposed immediately upstream of the beam current measuring device in an ion beam transport channel. The first electrode serves both as a suppressor electrode for repelling secondary electrons released from the beam current measuring device, back toward the beam current measuring device, and as a beam optical element other than the suppressor electrode.