Wafer Focus Spot Window Setting for Lithography Yield Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current focus spot window settings in photolithography technology do not achieve optimal yield for semiconductor products, as they are not tailored to individual machine processes, leading to inefficiencies and reduced production efficiency.
Innovation Solution
A method to determine a focus spot window by acquiring flatness and location information of a wafer, distribution information of abnormal dies, and wafer yield data, allowing for a process-specific focus spot window adjustment to improve lithography precision and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single focus spot window is set for all machines, then the device complexity is reduced, but the manufacturing precision and product yield deteriorate
Solution Approach 1:
The patent segments the focus spot window setting from a universal machine-level parameter to a specific process/wafer-level parameter. By dividing the focus spot window determination into process-specific configurations based on wafer flatness characteristics, each process can have optimized parameters rather than using a single generic setting for all machines and processes.
Solution Approach 2:
The patent applies local quality by determining focus spot windows based on local wafer flatness characteristics of specific regions. Different focus spot windows are assigned to different local regions of the wafer according to their flatness properties, allowing precise control tailored to each region's specific requirements rather than applying a uniform setting across the entire wafer.
2Manufacturing precision
If process-specific focus spot windows are determined using multiple parameters (flatness, abnormal die distribution, yield data), then the manufacturing precision improves, but the measurement and detection difficulty increases
Solution Approach 1:
The patent performs preliminary actions by measuring and analyzing wafer flatness characteristics, abnormal die distribution patterns, and yield data before determining the optimal focus spot window. This advance preparation and data collection enable the system to establish process-specific parameters proactively, avoiding the need for complex real-time adjustments during lithography operations.
Solution Approach 2:
The patent implements feedback mechanisms by utilizing wafer yield data and abnormal die distribution information to continuously refine and optimize focus spot window settings. The system feeds back performance data from previous processes to adjust and improve subsequent focus spot window determinations, creating a closed-loop optimization system that reduces measurement complexity over time through learned patterns.
Data Source
AI summary
The present disclosure provides methods for determining a focus spot window of a wafer and judging whether the wafer needs to be reworked, belonging to the field of semiconductor technology. The method for determining a focus spot window of a wafer includes: acquiring flatness information and location information of a local region of the wafer before exposure; acquiring distribution information of abnormal dies, process information corresponding to the abnormal dies, and data information related to wafer yield; and determining the focus spot window corresponding to a process according to the flatness information and the location information of the local region of the wafer, the distribution information of the abnormal dies, the process information corresponding to the abnormal dies, and the data information related to wafer yield.