Hydrogen Generator for Ion Implanter Arcing
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Solution Overview
Problem
Ion implantation systems face issues with aluminum ion implantation due to the production of insulating materials like aluminum nitride and alumina, which cause arcing and reduce the stability and lifetime of the ion source and beamline components.
Innovation Solution
Incorporating a hydrogen generator within the ion implantation system's gas box, electrically isolated from the terminal housing, to produce hydrogen gas at an elevated potential, which reacts with fluorine byproducts to form volatile gases, reducing the buildup of insulating materials and improving beam stability and source lifetime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If aluminum nitride or alumina are used as source material for aluminum ion implantation, then aluminum ions can be generated for doping, but insulating material is emitted along with the ions causing arcing between components
Solution Approach 1:
The patent extracts and removes the harmful insulating materials (aluminum nitride, alumina, and other aluminum-containing compounds) from the ion beam stream using a differential pumping system and cryopumps. This allows the aluminum ions to be utilized while the harmful byproducts are pumped away before they can cause arcing in downstream components.
Solution Approach 2:
The patent introduces hydrogen gas as an intermediary substance that reacts with the insulating aluminum-containing materials to form volatile aluminum hydride compounds. This chemical transformation converts the harmful insulating materials into volatile species that can be easily removed by vacuum pumping, preventing arcing.
2Productivity
If conventional etchant gases are used to ionize aluminum-containing materials, then aluminum ions are produced, but insulating material buildup reduces beam stability and source lifetime
Solution Approach 1:
The patent changes the chemical parameters of the ionization process by introducing hydrogen gas alongside conventional etchant gases. This modifies the chemical reactions occurring in the ion source, causing insulating materials to react with hydrogen and form volatile species rather than accumulating as solid deposits, thereby maintaining beam stability and extending source lifetime.
Solution Approach 2:
The patent converts the harmful insulating material buildup into a beneficial process by having the insulating materials react with hydrogen to form volatile aluminum hydride compounds. This transformation turns the problematic solid deposits into removable gaseous species that are pumped away, improving beam stability while maintaining aluminum ion production.
3Quantity of substance
If solid insulative materials are placed in the arc chamber for ionization, then aluminum ions can be extracted, but arcing occurs between various components of the ion implantation system
Solution Approach 1:
Hydrogen gas serves as an intermediary that reacts with aluminum-containing insulating materials in the arc chamber to form volatile aluminum hydride species. This prevents the accumulation of insulating materials on chamber walls and components, eliminating the source of arcing while maintaining aluminum ion extraction capability.
Solution Approach 2:
The patent replaces the mechanical/physical process of direct ionization with chemical reactions involving hydrogen. Instead of relying solely on physical sputtering or thermal desorption, the system uses chemical reactions to convert insulating materials into volatile species, which are then removed by vacuum pumping, preventing arcing.
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 use of a hydrogen generator in the ion implantation system enhances the stability of the ion beam and extends the operational life of the ion source and beamline components by eliminating insulating material buildup and increasing beam currents.
Implementation Method 1
a hydrogen generator configured to produce hydrogen gas for the ion source
Implementation Method 2
Ion sources in ion implanters typically generate the ion beam by ionizing a source material in an arc chamber
Implementation Method 3
a mass analysis device, typically a magnetic dipole performing mass dispersion or separation of the extracted ion beam
Data Source
AI summary
A terminal for an ion implantation system is provided, wherein the terminal has a terminal housing for supporting an ion source configured to form an ion beam. A gas box within the terminal housing has a hydrogen generator configured to produce hydrogen gas for the ion source. The gas box is electrically insulated from the terminal housing, and is further electrically coupled to the ion source. The ion source and gas box are electrically isolated from the terminal housing by a plurality of electrical insulators. A plurality of insulating standoffs electrically isolate the terminal housing from an earth ground. A terminal power supply electrically biases the terminal housing to a terminal potential with respect to the earth ground. An ion source power supply electrically biases the ion source to an ion source potential with respect to the terminal potential. Electrically conductive tubing electrically couples the gas box and ion source.