Cluster Tool Substrate Transfer Optimization
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Solution Overview
Problem
Current cluster tools in semiconductor fabrication face limitations in throughput and process variability due to long substrate transfer times and sensitivity to process recipe variations, particularly in track lithography processes, which affect device performance and increase costs of ownership.
Innovation Solution
A cluster tool design featuring multiple vertically stacked processing racks and dual robots with non-orthogonal trajectories, along with buffering stations accessible by both robots, to optimize substrate transfer paths and reduce collision avoidance time, thereby enhancing throughput and process uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If substrates are transferred between multiple processing chambers in a track lithography cluster tool, then the substrate can undergo complete lithography processing steps, but the transfer time becomes a significant portion of the total processing time, reducing throughput
Solution Approach 1:
The patent transitions from a planar/single-robot substrate transfer system to a three-dimensional/dual-robot system. Two robots operate in vertical stacks, enabling substrates to be transferred through multiple chambers simultaneously or in parallel sequences, thereby reducing the time penalty associated with transferring substrates between multiple processing chambers while maintaining complete lithography processing capability
2Productivity
If multiple processing chambers are arranged in a single stack, then the robot can access all chambers, but the robot trajectory becomes longer and collision avoidance time increases
Solution Approach 1:
The patent divides the single processing stack into multiple independent vertical stacks, each served by its own robot. This segmentation allows each robot to manage a shorter, simpler trajectory within its own stack, reducing collision avoidance time and trajectory complexity while maintaining access to multiple processing chambers through the distributed stack architecture
3Productivity
If chamber processing times are kept short for efficiency, then more substrates can be processed per hour, but the system becomes more sensitive to transfer time variations and process recipe variations
Solution Approach 1:
The patent implements a controller that coordinates multiple robots and monitors substrate transfer times and chamber processing times. This feedback system dynamically adjusts robot trajectories and timing to compensate for variations, ensuring that even with short chamber processing times, the overall system maintains consistent throughput and reduced sensitivity to process recipe variations
Data Source
AI summary
Embodiments generally provide an apparatus and method for processing substrates using a multi-chamber processing system (e.g., a cluster tool) that has an increased system throughput, increased system reliability, substrates processed in the cluster tool have a more repeatable wafer history. In one embodiment, non-orthogonal robot trajectories are used to assure reliable and high speed substrate transfer. In another embodiment, at least one buffering station is used to avoid collision and improve throughput. In another embodiment, optimal positioning of the robots are used to improve throughput.