Ion Implantation Source Bushing With Tilted Trenches

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The aging and deterioration of the source bushing in ion implantation systems lead to arcing and increased maintenance costs due to the accumulation of IMP by-products, which compromise the bushing's insulation capability.

Innovation Solution

A bushing structure with tilted trenches is designed to inhibit the accumulation of IMP by-products, and an image sensor and electrical measurement device are used to monitor the bushing's status, allowing for dynamic adjustment of operations and preventive maintenance scheduling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a source bushing is used to provide electrical insulation in high voltage ion implantation systems, then arcing is prevented, but the bushing accumulates IMP by-products that compromise insulation capability over time

Engineering Contradiction:

Improveelectrical insulation reliabilityVSAvoidbushing lifespan

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The inner surface of the bushing is segmented into multiple inclined planes or trenches that run axially along the bushing. This segmentation prevents continuous accumulation paths for IMP by-products, allowing them to be shed off the inclined surfaces rather than adhering continuously, thereby maintaining insulation reliability over extended periods

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of trying to prevent IMP by-product deposition on the bushing surface, the invention inverts the approach by creating inclined planes that actively shed the by-products. The inclination angle is designed so that gravitational and electrostatic forces cause the by-products to slide off rather than accumulate, reversing the typical adhesion problem

Inventive Principle:

Principle #13The other way round (Inversion)

2Productivity

If the bushing operates continuously in high voltage conditions, then ion implantation productivity is maintained, but aging and deterioration lead to increased maintenance costs

Engineering Contradiction:

Improveion implantation productivityVSAvoidmaintenance cost

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The inclined planes on the bushing surface create a self-cleaning mechanism where IMP by-products automatically shed due to gravity and electrostatic forces. This self-service feature reduces the need for manual cleaning and maintenance interventions, allowing continuous operation without increasing maintenance costs despite extended productivity

Inventive Principle:

Principle #25Self-service

3Reliability

If monitoring devices are added to detect bushing status, then preventive maintenance can be scheduled, but device complexity increases

Engineering Contradiction:

Improvebushing status monitoringVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Electrical measurement devices are integrated to continuously monitor the insulation resistance of the bushing in real-time. This feedback mechanism provides direct information about bushing degradation status, enabling predictive maintenance scheduling based on actual condition rather than fixed time intervals, thereby improving reliability without excessive complexity

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The invention replaces complex mechanical inspection and cleaning systems with electrical measurement devices that non-invasively monitor bushing condition. By substituting mechanical complexity with simple electrical resistance measurements, the system achieves effective monitoring while minimizing added device complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution enhances electrical insulation reliability, reduces maintenance costs, and improves the overall performance of the ion implantation system by preventing unwanted arcing and extending the bushing's lifespan.

Implementation Method 1

a gas or feed material contained the desired dopant material is introduced into an ion source, where a high energy is applied to ionize the gas or feed material to form the ion beam

Methodology Applied

Scientific EffectIonization: Ionisation

Implementation Method 2

An accelerating electric field is provided by IMP electrodes to extract and direct the ion beam moving toward the semiconductor wafer

Methodology Applied

Scientific EffectElectric field acceleration: Electric Field

Implementation Method 3

a tubular insulating source bushing is disposed within the IMP to provide an electrical isolation between various IMP conductor components

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Data Source

PatentUS11282673B2Ion implantation system and source bushing thereof

Publication Date: 2022.03.22 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

The present disclosure describes an ion implantation system that includes a bushing designed to reduce the accumulation of IMP by-produces on the bushing's inner surfaces. The ion implantation system can include a chamber, an ion source configured to generate an ion beam, and a bushing coupling the ion source and the chamber. The bushing can include (i) a tubular body having an inner surface, a first end, and a second end and (ii) multiple angled trenches disposed within the inner surface of the tubular body, where each of the multiple angled trenches extends towards the second end of the tubular body.