Buffer Storage Add-on for Semiconductor Workpiece Stacker
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Solution Overview
Problem
In semiconductor fabrication facilities, the uniform flow of workpieces across processing steps and tools is challenging due to unexpected events like tool downtime and maintenance, leading to accumulation issues, and the storage of sensitive items like photolithography reticles requires a clean environment to prevent physical and chemical damage.
Innovation Solution
A buffer storage assembly is introduced as an add-on to existing workpiece stackers, featuring a storage chamber and a robot system that interfaces with loadlock stations to transfer containers and workpieces, enabling external storage and efficient container management, including the supply of empty containers and storage of workpieces within containers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If workpieces are stored in a sealed storage chamber with constant purging and inert gas flow, then cleanliness and protection from chemical reactions is improved, but device complexity and energy consumption increase
Solution Approach 1:
The storage system is divided into multiple sealed storage chambers, each independently controlled with its own purging and inert gas flow systems. This segmentation allows different cleanliness levels to be maintained in different chambers based on their specific requirements, reducing the overall complexity compared to a single large controlled chamber.
Solution Approach 2:
A robot system acts as an intermediary between the sealed storage chambers and the external environment. The robot transfers workpieces through loadlock stations without breaking the seal of the storage chambers, maintaining cleanliness while enabling access and reducing the complexity of direct human intervention in controlled environments.
2Productivity
If a robot system with loadlock stations is used to transfer workpieces, then automation and productivity are improved, but device complexity increases
Solution Approach 1:
The robot system is designed with multi-functionality, serving as both the transfer mechanism between storage chambers and the interface with external transport systems. The loadlock stations perform multiple functions including sealing, pressure equalization, and workpiece transfer, reducing the need for separate dedicated components and thereby managing complexity while maintaining high productivity.
3Productivity
If buffer storage assembly is added as an add-on to existing stacker, then storage capacity and productivity are improved, but device complexity increases
Solution Approach 1:
The buffer storage assembly is designed as an add-on module that merges with the existing stacker system. The robot system serves dual purposes by handling both the original stacker operations and the buffer storage transfers. Loadlock stations are integrated to work with both the main stacker and buffer chambers, combining functions to minimize overall system complexity while expanding storage capacity and productivity.
Data Source
AI summary
The present invention relates to apparatuses and methods to store and transfer objects, and more particularly to workpiece stocker configurations such as stacker for semiconductor wafers, reticles or carrier boxes.