EUV Dose Calibration for Critical Dimension Uniformity
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Solution Overview
Problem
Conventional dose mapper maps and applications suffer from limitations in achieving uniform critical dimension (CDU) and within wafer (WiW) uniformity during semiconductor manufacturing, particularly in EUV lithography, leading to degraded device performance due to process-dependent variations.
Innovation Solution
A method involving intra dose correction for reticle-dependent deviation, thru-slit dose sensitivity correction for time-dependent deviation, and inter dose correction for process-dependent deviation is employed, utilizing a semiconductor substrate processing system with EUV lithography capabilities to calibrate and enhance CDU.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional dose mapper maps are used to measure and adjust lithography conditions, then critical dimension uniformity (CDU) and within wafer uniformity are improved, but calibration time and process complexity increase
Solution Approach 1:
The patent pre-calculates and stores dose mapper values for various positions on the wafer before actual lithography processing. This preliminary preparation of correction data allows for rapid application during production without performing full calibration measurements each time, thereby reducing calibration time while maintaining CDU improvement benefits
Solution Approach 2:
The patent pre-calculates and stores dose mapper values for various positions on the wafer before actual lithography processing. This preliminary preparation of correction data allows for rapid application during production without performing full calibration measurements each time, thereby reducing calibration time while maintaining CDU improvement benefits
2Manufacturing precision
If comprehensive dose correction procedures are implemented to improve CDU consistency, then manufacturing precision improves, but device complexity and process steps increase
Solution Approach 1:
The patent applies position-specific dose mapper correction values to different regions of the wafer, tailoring the exposure dose to local requirements. This localized correction approach improves CDU consistency across the wafer surface while avoiding the need for complex global process adjustments
Solution Approach 2:
The patent uses pre-calculated dose mapper maps that can be copied and applied to multiple wafers and production runs. This copying of validated correction data simplifies the process by eliminating the need to recreate complex calibration procedures for each new production batch
Data Source
AI summary
A critical dimension uniformity control method is provided. The method includes gathering a first CDU by a first critical dimension from a first wafer after being processed by a first surface process. The method includes determining a first calibration process based on the first CDU. The determining includes an intra dose correction step for correcting reticle-dependent deviation, a thru-slit dose sensitivity correction step for correcting time-dependent deviation, and an inter dose correction step for correcting process-dependent deviation. The method includes calibrating the first surface process by the first calibration process to determine a second surface process different from the first surface process.