Wafer Inspection Optimization via Cross-Process Feedback
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Solution Overview
Problem
Conventional substrate processing methods in liquid immersion exposure systems for semiconductor manufacturing face challenges in maintaining optimal conditions, leading to reduced yield due to issues like bubble formation, dust, contamination, and inadequate inspection and removal of foreign materials, which affect the quality of the pattern formed on substrates.
Innovation Solution
A method and system that optimize inspection conditions by sending information on processing results and operating states of multiple processing apparatuses to inspection devices, and include a liquid/foreign material removal device to assess and address potential adverse effects of liquid and foreign materials on substrates, ensuring efficient quality inspection and improved yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If liquid immersion exposure is used to improve resolution, then manufacturing precision is improved, but harmful factors (bubbles, dust, contamination) increase
Solution Approach 1:
The system performs preliminary inspection of the substrate before liquid immersion exposure to detect potential defects. By identifying substrates with pre-existing contamination or defects before the exposure process, the system can prevent further deterioration and ensure only suitable substrates proceed to the high-precision liquid immersion exposure, thereby maintaining manufacturing precision while managing harmful factors.
Solution Approach 2:
The system implements feedback control by inspecting substrates after liquid immersion exposure and before development. This intermediate inspection provides feedback on the quality of substrates that have undergone liquid immersion exposure, allowing the system to identify and separate defective substrates. This feedback mechanism enables continuous optimization of the liquid immersion exposure process while maintaining high manufacturing precision.
2Measurement precision
If inspection is performed after exposure to detect abnormalities, then measurement precision is improved, but productivity is reduced
Solution Approach 1:
The system performs preliminary inspection before liquid immersion exposure to identify and exclude substrates with pre-existing defects. By conducting this preliminary screening, the system prevents defective substrates from undergoing the time-consuming liquid immersion exposure and subsequent development processes, thereby reducing waste and improving overall productivity while maintaining high inspection accuracy through the preliminary detection of abnormalities.
3Measurement precision
If multiple films are formed and inspected separately, then measurement precision for each film is improved, but device complexity increases
Solution Approach 1:
The inspection system is designed with multi-functionality to handle multiple film types (resist film, topcoat film, etc.) and multiple inspection stages (before exposure, after liquid immersion exposure, after development) using a unified inspection apparatus. This universal inspection system can detect various types of defects including bubbles, dust, and contamination across different film layers, thereby maintaining measurement precision while reducing device complexity by consolidating multiple inspection functions into a single system.
Data Source
AI summary
A wafer measurement/inspection instrument receives information on at least one of a processing result and an operating state of at least one of a coater/developer that performs film forming/resist processing to a wafer and an exposure apparatus that performs liquid immersion exposure to the wafer, and optimizes inspection conditions of the wafer based on the received information (steps 501 and 517). With this operation, quality inspection of the wafer can be efficiently performed, and as a consequence, it becomes possible to efficiently perform processing to the wafer.