Semiconductor Lithography Alignment Correction for APC Noise Reduction
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Solution Overview
Problem
Advanced process control (APC) noises caused by differences in device performance or structure between measurement and lithography apparatuses in semiconductor manufacturing processes lead to challenges in controlling overlay errors, affecting yield rate and productivity.
Innovation Solution
A semiconductor manufacturing method that groups wafers based on alignment mark position errors and calculates a feedforward position correction value, using a processor to control the lithography apparatus with this value, reducing APC noises and improving overlay error control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If alignment mark position errors are measured and fed forward to lithography apparatus for position correction, then overlay error control is improved, but APC noises are introduced due to device performance differences between measurement and lithography apparatuses
Solution Approach 1:
The patent introduces a processor as an intermediary that receives alignment mark position error data from the measurement apparatus, processes this data by comparing it with reference data, and generates corrected position correction values for the lithography apparatus. This intermediary processing layer filters out APC noises while preserving the useful alignment information, thereby resolving the contradiction between improving overlay error control and avoiding the introduction of harmful APC noises.
Solution Approach 2:
The patent implements a feedback mechanism where the processor continuously compares measured alignment mark position errors with reference error values and adjusts the position correction values accordingly. This feedback loop allows the system to learn from historical data and compensate for device differences between measurement and lithography apparatuses, effectively reducing APC noises while maintaining precision in overlay error control.
2Manufacturing precision
If position correction is performed based on measured alignment mark position errors, then manufacturing precision is improved, but device differences between measurement apparatus and lithography apparatus cause control difficulties
Solution Approach 1:
The patent changes the parameter used for position correction from raw measured alignment mark position errors to corrected position correction values that have been processed and adjusted based on reference data. This parameter transformation adapts the correction values to account for device-specific characteristics of both the measurement apparatus and lithography apparatus, thereby improving manufacturing precision while reducing control difficulties caused by device differences.
Solution Approach 2:
The patent performs preliminary processing of alignment mark position error data by comparing it with reference error values before feeding the corrected values to the lithography apparatus. This preliminary action prepares the correction data in advance, filtering out noise and adjusting for device differences, which simplifies subsequent control operations and improves reliability despite variations between measurement and lithography apparatuses.
Data Source
AI summary
A semiconductor manufacturing apparatus and a semiconductor manufacturing method thereof are provided. Wafers are grouped into a first wafer group and a second wafer group according to alignment mark position errors of the wafers and a first threshold value. The alignment mark position errors of the first wafer group are greater than the first threshold value, and the alignment mark position errors of the second wafer group are less than or equal to the first threshold value. A feedforward position correction value is calculated according to a difference between the alignment mark position errors of the first wafer group and a reference error value. A lithography process is performed on the wafers according to the feedforward position correction value.