Neutral Beam Diagnostic Apparatus for Dosimetry Control
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Solution Overview
Problem
Existing methods for processing workpieces with neutral beams face challenges in characterizing and controlling the dosimetry of neutral gas cluster ion beams, leading to inconsistencies in surface processing due to charge-induced damage and space charge defocusing, particularly for insulating materials and high-energy applications.
Innovation Solution
A diagnostic method and apparatus using sensors to characterize neutral beams and dissociated neutral beams, enabling precise dosimetry by measuring the flux and energy of neutral particles, which allows for improved control over workpiece processing, especially for insulating materials and high-energy applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional ion beams are used for surface processing, then processing capability is improved, but charge-induced damage occurs on insulating materials
Solution Approach 1:
The patent converts the harmful charge effect into a beneficial separation mechanism by using electrostatic fields to deflect charged ions away from the workpiece while allowing neutral atoms to reach the surface. This resolves the contradiction by eliminating the harmful charge-induced damage while preserving the processing capability of the atom beam.
Solution Approach 2:
The patent changes the charge state parameter of the beam particles from charged (ions) to neutral (atoms) by using a charge exchange cell. This parameter change allows the beam to maintain processing capability while eliminating charge-induced damage on insulating materials.
2Object-affected harmful factors
If gas cluster ion beams are used to reduce charge per mass, then charge-induced damage is reduced, but space charge defocusing still occurs at moderate to high currents
Solution Approach 1:
The patent uses the space charge effect, which normally causes defocusing, as a beneficial separation mechanism. The electrostatic fields designed to deflect charged particles also exploit space charge effects to enhance the separation between charged and neutral beam components, improving both damage reduction and beam stability.
Solution Approach 2:
The patent changes the charge state parameter from charged to neutral, eliminating space charge effects entirely. Neutral atoms do not experience space charge defocusing, allowing high-current beams to maintain stable focusing while processing insulating materials without charge-induced damage.
3Object-affected harmful factors
If neutral beams are used to eliminate charge effects, then charge-induced damage is prevented, but dosimetry control becomes difficult
Solution Approach 1:
The patent implements feedback control by using Faraday cup sensors to monitor the charged beam component and neutral beam sensors to monitor the neutral component. This feedback information is used to adjust beam parameters in real-time, enabling precise dosimetry control of neutral beams while maintaining the benefits of charge elimination.
Solution Approach 2:
The patent creates a multi-functional beam system that can operate in both charged and neutral modes. The same beam generation system can produce charged ion beams for applications requiring dosimetry control and neutral atom beams for applications requiring elimination of charge effects, providing universal versatility.
4Quantity of substance
If gas cluster ions with single or small multiple charges are used, then mass-flow transport capability is improved, but target charging problems persist
Solution Approach 1:
The patent uses electrostatic deflection to convert the charge property that enables mass-flow transport into a separation mechanism. The charged cluster ions are deflected away from the workpiece, while neutral atoms reach the surface, eliminating target charging while preserving the mass-flow capability established during beam formation.
Solution Approach 2:
The patent changes the charge state parameter from charged to neutral using a charge exchange cell. This allows the beam to maintain the high mass-flow capability of gas cluster ions while eliminating target charging problems by delivering neutral atoms to the workpiece surface.
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 provides repeatable and effective surface processing by accurately controlling the dose and energy of neutral beams, reducing charge-induced damage and space charge effects, and enabling the use of neutral beams for applications that conventional ion beams cannot handle.
Implementation Method 1
A diagnostic method and apparatus using sensors to characterize neutral beams and dissociated neutral beams, enabling precise dosimetry by measuring the flux and energy of neutral particles
Data Source
AI summary
An apparatus and method for characterizing a particle beam provides receiving a particle beam in a central region of a reduced pressure enclosure; impacting the received beam against a beam strike that is thermally isolated from the enclosure; measuring a temperature change of the beam strike due to the impacting beam; measuring a pressure change in the enclosure due to receiving the beam; and processing the measured temperature change and the measured pressure change to determine beam characteristics.