Boat Elevator Positioning for Faster Wafer Loading in Process Furnaces
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Solution Overview
Problem
Existing substrate processing apparatuses face inefficiencies in loading and unloading wafers into and from boats due to stroke limitations of the wafer transfer device, which can prolong vacuuming times and reduce throughput.
Innovation Solution
A substrate processing apparatus with a boat elevator that supplements the stroke of the wafer transfer device, allowing for multiple positions to minimize shifts and reduce transfer time by optimizing wafer loading and unloading operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If the wafer transfer device stroke is set to be short to reduce chamber volume, then the chamber size is reduced, but the stroke is insufficient to cover the entire wafer holding range
Solution Approach 1:
The transfer system is segmented into two independent components: a wafer transfer device with limited stroke for precise wafer manipulation, and a boat elevator with vertical stroke for positioning the boat. This segmentation allows each component to have optimized stroke length for its specific function, resolving the contradiction between compact chamber size and sufficient transfer range.
Solution Approach 2:
The boat elevator acts as an intermediary mechanism between the wafer transfer device and the boat. It supplements the insufficient stroke of the wafer transfer device by providing additional vertical movement capability, enabling the system to achieve full wafer holding range coverage without requiring the transfer device to have excessive stroke.
2Adaptability or versatility
If the boat elevator performs multiple position shifts to enable wafer transfer, then transfer flexibility is improved, but the number of shifts increases operation time
Solution Approach 1:
The boat elevator is pre-positioned at optimal locations before wafer transfer operations begin. The controller plans the transfer sequence in advance, predicting which positions will be needed and pre-moving the boat elevator to those positions. This preliminary action reduces the number of shifts required during actual wafer transfer, improving both flexibility and speed.
Solution Approach 2:
The controller continuously monitors the transfer operation status and uses feedback to dynamically adjust the boat elevator positioning strategy. By receiving real-time information about wafer transfer progress and boat position, the controller can optimize subsequent movements to minimize shifts while maintaining transfer flexibility.
Data Source
AI summary
There is provided a technique that includes: a boat including plural slots to hold at least one substrate; a process furnace that processes the at least one substrate held in the boat; a boat elevator that raises and lowers the boat; a transfer device that transfers the at least one substrate between plural carriers where the at least one substrate is stored and the boat; and a controller capable of controlling the boat elevator and the transfer device, wherein the controller sets plural positions where the transfer device transfers the at least one substrate to the boat elevator, and select the positions to minimize a number of shifts among the positions of the boat elevator or total time taken during the shifts.