Radiation-Shielded Wafer Load Ports for Decay-Gated Access
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Solution Overview
Problem
Ion implantation processes in semiconductor manufacturing result in radioactive wafers due to high-energy ion implantation, posing safety risks and affecting throughput due to required wait times for radiation decay before handling.
Innovation Solution
A radiation safety apparatus with a safety fence and interlockable access doors, comprising radiation shields and a controller to manage access based on radiation decay, ensuring safe handling of radioactive wafers by preventing access until decay is complete.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high energy ion implantation is performed to achieve desired doping, then manufacturing precision is improved, but radioactive wafers are produced requiring wait times
Solution Approach 1:
The system segments the wafer processing workflow by creating separate containment regions for radioactive wafers. Multiple load ports are divided into isolated sections, allowing non-radioactive wafers to be processed simultaneously while radioactive wafers undergo decay in dedicated containment areas. This segmentation eliminates the need for complete system idle time during radiation decay periods.
Solution Approach 2:
The system performs preliminary containment and isolation of radioactive wafers immediately after ion implantation. By pre-establishing containment regions and interlock mechanisms before radiation decay occurs, the system prepares the infrastructure needed for safe simultaneous processing of multiple wafers, reducing overall wait time through proactive safety measures.
2Reliability
If wait times are implemented for radiation decay before handling wafers, then operator safety is improved, but system throughput decreases
Solution Approach 1:
The system divides the processing environment into multiple isolated containment regions, each capable of holding radioactive wafers separately. This allows operators to safely access non-radioactive wafers in other regions while radioactive wafers undergo decay, maintaining throughput while ensuring operator safety through spatial separation and controlled access via interlockable doors.
Solution Approach 2:
The system introduces interlockable access doors and containment regions as intermediary safety mechanisms between operators and radioactive wafers. These intermediaries control radiation exposure by requiring proper safety protocols to be followed while enabling continuous system operation through monitored, controlled access during decay periods.
3Productivity
If multiple wafers are processed simultaneously to increase throughput, then productivity is improved, but radiation exposure risk increases
Solution Approach 1:
The system segments the processing system into multiple independent containment regions, each capable of holding and processing wafers separately. This allows simultaneous processing of multiple wafers while maintaining physical isolation of radioactive materials, enabling high throughput without increasing radiation exposure risk through proper spatial compartmentalization and controlled access.
Solution Approach 2:
The system applies different safety characteristics to different regions based on their specific needs. Containment regions holding radioactive wafers have enhanced interlockable access controls and radiation shielding, while regions with non-radioactive wafers have standard access. This localized quality approach enables simultaneous processing while maintaining appropriate safety measures only where radiation exposure risk exists.
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
Enhances safety by maintaining safe radiation exposure levels and optimizing throughput by allowing simultaneous processing of multiple wafers while ensuring operator safety.
Implementation Method 1
The plurality of radiation shields are configured to attenuate the radioactive radiation to an external region that is external to the one or more containment regions
Implementation Method 2
The one or more containment regions are further respectively associated with one or more radioactive sources that emit radioactive radiation
Data Source
AI summary
A radiation safety apparatus for a semiconductor processing system has a safety fence with a support frame and radiation shields defining containment regions associated with load ports of the semiconductor processing system. The containment regions are associated with radioactive sources that emit radioactive radiation, where radiation shields attenuate the radiation to a region external to the containment regions. The radiation shields have access doors movably coupled to the support frame to provide access to the containment regions. Interlocks are provided with the access doors to selectively lock the access doors in a closed position to control the access to the containment regions from the external region through the access doors. A controller controls the interlocks based on a radiation decay associated with each of the radioactive sources and a predetermined safe radiation exposure level.