Substrate Transfer Timing Control for Stable Post-Exposure Delay
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Solution Overview
Problem
Existing substrate transfer methods in semiconductor manufacturing fail to maintain consistent post-exposure bake (PEB) times across multiple wafers, leading to non-uniformity in resist pattern width due to variations in post-exposure delay (PED) times.
Innovation Solution
A substrate transfer method in a substrate processing apparatus that includes a transfer mechanism group and controller to manage transfer times, ensuring the longest section transfer time is maintained for each wafer, using first, second, and third transfer controls to regulate the carry-in and carry-out of wafers based on maximum post-exposure cycle times, thereby stabilizing PED times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wafers are transferred using conventional transfer methods, then the transfer process is simple, but the post-exposure delay time varies between wafers causing non-uniform resist pattern width
Solution Approach 1:
The transfer control system dynamically adjusts the carry-in and carry-out timing of wafers based on the maximum section transfer time calculated from downstream module transfer times. This dynamic timing adjustment ensures that post-exposure delay time remains consistent across all wafers, resolving the uniformity issue without requiring complex hardware modifications
Solution Approach 2:
The control device calculates the maximum section transfer time by acquiring transfer times from all downstream sections and uses this feedback information to determine the optimal carry-in and carry-out timing. This feedback mechanism ensures that variations in downstream transfer times are compensated for, maintaining consistent post-exposure delay times and uniform resist pattern width
2Manufacturing precision
If the transfer timing is adjusted to maintain constant post-exposure delay time, then manufacturing precision improves, but the control complexity increases
Solution Approach 1:
The control device performs preliminary calculation of the maximum section transfer time before executing the transfer operation. By determining the bottleneck section transfer time in advance and setting the carry-in and carry-out timing based on this pre-calculated value, the system maintains consistent post-exposure delay times without requiring complex real-time adjustments during transfer
Solution Approach 2:
The system changes the timing parameters (carry-in time and carry-out time) based on the calculated maximum section transfer time. By adjusting these parameters dynamically while keeping the control logic relatively simple, the system achieves consistent post-exposure delay times across all wafers without significantly increasing control complexity
Data Source
AI summary
A substrate transfer method performed in a substrate processing apparatus including a transfer mechanism group configured to transfer a substrate into a carrier via a module group and an exposure apparatus is provided. The transfer mechanism group includes a first transfer mechanism configured to transfer the substrate in an order of a pre-stage module, the exposure apparatus, and a first post-stage module, and a second transfer mechanism configured to transfer the substrate in an order of the first post-stage module, a heating module, a developing module, and a second post-stage module, and a post-stage transfer mechanism. The substrate transfer method includes acquiring a section transfer time required to transfer the substrate to a next transfer section; and performing a carry-in or a carry-out of the substrate into/from the exposure apparatus based on a maximum section transfer time, which is the longest in the acquired section transfer times.