EUV Mask Auxiliary Patterns for Defect Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional defect correction methods for reflection-type masks in EUV lithography struggle with accurately specifying and correcting phase defects and contamination defects, leading to inefficient and labor-intensive processes due to the difficulty in determining defect type and size, which affects the enlargement of opening patterns and exposure accuracy.
Innovation Solution
A defect correction technique involving the use of auxiliary patterns formed in the periphery of opening patterns on the reflection-type mask, which compensates for exposure deficiencies by adjusting the light amount and pattern dimensions, allowing for precise defect correction without frequent mask movement and evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional defect correction methods are used for reflection-type masks in EUV lithography, then defect correction can be performed, but the process becomes inefficient and labor-intensive due to difficulty in determining defect type and size
Solution Approach 1:
The patent applies preliminary action by pre-forming auxiliary patterns around opening patterns during mask fabrication. These auxiliary patterns are prepared in advance with specific designs (different sizes, shapes, and positions) that correspond to various defect types and sizes. When a defect is detected during inspection, the pre-prepared auxiliary patterns can be directly selected and used for correction without requiring complex real-time analysis of defect characteristics, thereby streamlining the defect correction process.
2Manufacturing precision
If auxiliary patterns are added to compensate for exposure deficiencies, then pattern transfer accuracy improves, but mask complexity increases
Solution Approach 1:
The patent applies local quality by adding auxiliary patterns only in specific locations where defects are detected, rather than uniformly across the entire mask. The auxiliary patterns are strategically placed around the affected opening patterns based on the defect's position, type, and size. This localized approach improves pattern transfer accuracy at defect-prone areas while minimizing the overall increase in mask complexity.
Solution Approach 2:
The patent applies partial action by selectively adding auxiliary patterns only where needed for defect correction, rather than adding them to all opening patterns. The number and configuration of auxiliary patterns are adjusted based on the specific defect characteristics, providing just enough compensation to achieve accurate pattern transfer without unnecessary additions that would increase mask complexity.
3Measurement precision
If frequent mask movement and evaluation are performed for defect correction, then defect accuracy improves, but process time and operational load increase
Solution Approach 1:
The patent applies preliminary action by pre-designing and pre-positioning auxiliary patterns during mask fabrication with various configurations that correspond to different defect types and sizes. During defect correction, inspection results directly indicate which pre-prepared auxiliary patterns should be used, eliminating the need for frequent mask movements and iterative evaluations. The correction process becomes a direct selection and application of the appropriate pre-prepared pattern.
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
This method enables efficient and accurate defect correction for phase and contamination defects, improving the miniaturization of semiconductor integrated circuit devices by ensuring precise pattern transfer and reducing the load on the defect correction process.
Implementation Method 1
a multilayer reflective substrate utilizing reflection (Bragg reflection) by a multilayer film obtained by stacking, for example, an Mo (molybdenum) layer and an Si (silicon) layer is used as a mask blank of the EUV lithography
Implementation Method 2
a circuit pattern made of an adsorption layer formed on the multilayer film blank. This reflection-type mask is a mask utilizing Bragg reflection and the wavelength of exposure light thereof is as extremely short as 13.5 nm
Data Source
AI summary
A manufacturing technique of a semiconductor integrated circuit device utilizing a defect correction technique of a reflection-type mask using extreme ultraviolet (EUV) light with a wavelength of about 13.5 nm as an exposure light source is provided. An auxiliary pattern having an opening diameter finer than that of an opening pattern in which a phase defect is generated is formed in an absorption layer in the vicinity of the opening pattern. The auxiliary pattern is a pattern for adjusting the exposure light amount at the time when the opening pattern is transferred to a photoresist film on a wafer.