Ion Implanter Neutron Scattering Layout for Deep Implantation
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Solution Overview
Problem
In semiconductor manufacturing, high-energy ion implantation leads to neutron radiation generation, requiring effective neutron dose rate management to prevent equipment damage and maintain productivity, but existing methods are inefficient due to the need for extensive shielding and labor-intensive door operations in radiation management areas.
Innovation Solution
An ion implantation method and system that strategically deploys neutron ray scattering members around the ion implanter, varying thickness based on distance from the neutron generation source to control neutron dose rates without complete shielding, using materials like high-density polyethylene and boron compounds to reduce neutron radiation outside the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If high-energy ion beam is used for deep region implantation, then implantation depth is improved, but neutron radiation generation increases causing equipment damage and safety issues
Solution Approach 1:
The patent introduces a neutron ray scattering member as an intermediary substance between the ion beam source and the surrounding environment. This scattering member (made of materials like polyethylene, boron compounds, or concrete) intercepts and scatters neutron rays generated during high-energy ion implantation, preventing them from damaging equipment and compromising safety, thus enabling deep region implantation without proportionally increasing harmful radiation effects
Solution Approach 2:
The patent converts the harmful neutron radiation generated during high-energy ion implantation into a manageable phenomenon by using scattering members that redirect neutron rays. Instead of allowing neutrons to cause equipment damage, the scattering members redirect them in controlled ways, transforming a harmful byproduct into a controllable aspect of the implantation process that enables deeper implantation
2Object-affected harmful factors
If extensive shielding is used to reduce neutron radiation, then radiation safety is improved, but device complexity and cost increase
Solution Approach 1:
The patent applies local quality by positioning neutron ray scattering members specifically at locations where neutron radiation is most problematic, rather than using uniform extensive shielding throughout the device. The scattering members are strategically placed around the ion beam source and in pathways where neutrons would cause damage, providing targeted radiation protection that reduces overall device complexity while maintaining safety
Solution Approach 2:
The patent changes the approach from using thick extensive shielding to using scattering members with specific material properties (hydrogen content, boron concentration) that are optimized for neutron scattering. By changing the material parameters and placement strategy rather than simply increasing shielding thickness, the system achieves radiation protection with reduced complexity
3Object-affected harmful factors
If complete shielding is implemented to eliminate neutron radiation, then radiation safety is improved, but productivity decreases due to labor-intensive door operations in radiation management areas
Solution Approach 1:
The scattering members act as intermediaries that contain and scatter neutrons within the device structure itself, eliminating the need for separate radiation management areas with labor-intensive access controls. This allows operators to work in normal environments while the scattering members handle radiation protection, significantly improving productivity
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
Effectively suppresses neutron dose rates outside the implanter to safe levels, reducing the need for extensive shielding and labor, thus enhancing productivity and reducing costs by minimizing the amount of scattering material required.
Implementation Method 1
a neutron ray scattering member 76a, 76b, 77a, 77b that scatters a neutron ray 90, 91, 92, 93 generated in the device main body 58
Implementation Method 2
The ions accelerated to ultra-high energy may collide with a member present in a beamline of the ion implanter to cause a nuclear reaction. The nuclear reaction that occurs may generate a radiation such as a neutron ray
Data Source
AI summary
An ion implantation method includes: acquiring a measured value of a neutron dose rate measured at a predetermined position in an ion implanter when a first ion beam containing a first ion species is transported along a beamline; determining whether the measured value exceeds a predetermined threshold; transporting a second ion beam containing a second ion species having a larger mass number than the first ion species along the beamline when the measured value exceeds the predetermined threshold; and irradiating a wafer with the transported first ion beam after transport of the second ion beam.