Ion Beam Neutralization via Multi-Cusp Magnetic Field and Charged Particle Injection
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Solution Overview
Problem
Existing ion implanter technologies face challenges in transporting low-energy, high-current ion beams due to space charge blow-up and limited capability for effective neutralization, particularly due to ion beam distortion and high-energy neutral particles impacting the target at undesired energy levels, which affects semiconductor manufacturing.
Innovation Solution
A charged particle injection system utilizing a beamguide with a dipole field and multi-cusp magnetic field configuration, where charged particles are injected through apertures aligned with magnet arrays to generate magnetic pockets, facilitating effective diffusion and neutralization of the ion beam along its path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If low-energy ion beams are used to achieve shallow dopant profiles, then manufacturing precision is improved, but beam quality deteriorates due to space charge blow-up
Solution Approach 1:
A plasma source is introduced as an intermediary between the ion source and the wafer. This plasma provides a high density of electrons that act as a mediator to neutralize the space charge of the low-energy ion beam, preventing beam blow-up while maintaining beam quality and enabling shallow dopant profiles
Solution Approach 2:
The system changes the energy parameter by decelerating a high-energy ion beam to a low energy level before implantation. However, this creates space charge issues that are resolved by introducing plasma to maintain beam quality at the lower energy state
2Productivity
If high-current ion beams are used to achieve reasonable production throughput, then productivity is improved, but beam quality deteriorates due to mutual repulsion and divergence
Solution Approach 1:
Plasma is introduced as an intermediary that provides electrons to neutralize the space charge of high-current ion beams. This allows high beam currents to be transported without excessive divergence, maintaining beam quality while achieving reasonable production throughput
3Manufacturing precision
If high-energy ion beams are decelerated to low energy levels, then manufacturing precision is improved, but harmful factors increase due to charge exchange generating high-energy neutral particles
Solution Approach 1:
A plasma source is positioned upstream in the beam path to pre-neutralize the ion beam before deceleration. This preliminary neutralization reduces the density of ions available for charge exchange during deceleration, thereby reducing the generation of harmful high-energy neutral particles that would otherwise impact the wafer at incorrect energies
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 enhances the neutralization of low-energy ion beams by diffusing charged particles within the ion beam path, reducing beam divergence and maintaining desired energy levels, thereby improving the quality and accuracy of ion implantation in semiconductor manufacturing.
Implementation Method 1
A charged particle injection system utilizing a beamguide with a dipole field and multi-cusp magnetic field configuration
Implementation Method 2
multi-cusp magnetic field configuration, where charged particles are injected through apertures aligned with magnet arrays to generate magnetic pockets
Implementation Method 3
facilitating effective diffusion and neutralization of the ion beam along its path
Implementation Method 4
a beamguide configured to transport an ion beam through a dipole field
Data Source
AI summary
A system for ion beam neutralization includes a beamguide configured to transport an ion beam through a dipole field, a first array of magnets and a second array of magnets configured to generate a multi-cusp magnetic field, the first array of magnets being on a first side of the ion beam path and the second array of magnets being on a second side of the ion beam path. The system may further include a charged particle source having one or more apertures configured to inject charged particles into the ion beam. The system may furthermore align the one or more apertures with at least one of the first array of magnets and the second array of magnets to align the injected charged particles from the charged particle source with one or more magnetic regions for an effective charged particle diffusion into the ion beam.