On-Tool Wafer OCR Verification to Prevent ID Mismatch Scrap
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Solution Overview
Problem
Existing methods for identifying semiconductor wafers in fabrication processes require transporting wafers to separate tools for mismatch checks, leading to long handling times and increased scrap due to out-of-specification events.
Innovation Solution
Integration of an OCR device on wafer processing tools to read wafer IDs in real-time, allowing for immediate matching with predetermined IDs and reducing scrap by informing transport tools to fix mismatches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wafers are transported to separate tools for mismatch checks, then wafer ID verification can be performed, but handling time increases and wafer scrap increases
Solution Approach 1:
The patent combines the OCR device for wafer ID verification directly onto the processing tool, merging two previously separate functions (processing and verification) into a single integrated system. This eliminates the need to transport wafers to separate tools for ID checks, thereby reducing handling time while maintaining verification accuracy
Solution Approach 2:
The patent introduces an OCR device as an intermediary component that enables direct optical reading of wafer IDs on the processing tool itself. This intermediary technology allows verification without physical transport, resolving the contradiction between accurate verification and time loss
2Reliability
If wafers are transported to separate tools for mismatch checks, then wafer ID verification can be performed, but wafer scrap increases due to Q-time over events
Solution Approach 1:
By integrating the OCR verification system directly on the processing tool, the patent eliminates delays associated with transporting wafers to separate tools. This prevents Q-time over events that would otherwise cause wafer scrap, while maintaining reliable ID verification through the combined system
Solution Approach 2:
The patent performs wafer ID verification as a preliminary action before processing begins, using the integrated OCR device. This early verification prevents processing of mismatched wafers, avoiding scrap generation while ensuring verification accuracy
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
Reduces wafer scrap by enabling real-time ID verification during processing, thus avoiding Q-time over events and improving production efficiency.
Implementation Method 1
a device configured to read an optical character disposed on the semiconductor wafer
Data Source
AI summary
Apparatus and methods for determining wafer characters are disclosed. In one example, an apparatus is disclosed. The apparatus includes: a processing tool configured to process a semiconductor wafer; a device configured to read an optical character disposed on the semiconductor wafer while the semiconductor wafer is located at the apparatus for wafer fabrication; and a controller configured to determine whether the optical character matches a predetermined character corresponding to the semiconductor wafer based on the optical character read in real-time at the apparatus.