EUV Lithography Mask Trench Conductive Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the semiconductor industry, the scaling down of integrated circuits (ICs) leads to increased complexity in processing and manufacturing, requiring advanced lithography techniques, but existing methods face challenges such as potential differences in surface potential during EUV lithography, which can cause arcing and particle discharge, affecting the accuracy of pattern transfer.
Innovation Solution
A lithography mask is designed with a reflective film stack and an absorptive film stack, featuring a conductive material at the bottom of trenches to neutralize potential differences, preventing arcing and reducing particle discharge by grounding the mask surfaces, thus improving the accuracy of pattern transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If advanced lithography techniques are used to achieve higher resolution and smaller geometry sizes, then manufacturing precision and production efficiency are improved, but potential differences in surface potential cause arcing and particle discharge that deteriorate pattern transfer accuracy
Solution Approach 1:
A conductive layer is deposited at the bottom of trenches in the mask structure to equalize the electrical potential across the mask surface. This equipotential layer prevents potential differences that would otherwise cause arcing and particle discharge during EUV lithography exposure, thereby maintaining both high manufacturing precision and process reliability
Solution Approach 2:
The conductive layer acts as an intermediary element between the mask structure and the ground, providing a controlled electrical pathway that prevents uncontrolled discharge. This intermediary layer neutralizes static charge buildup without interfering with the optical performance of the mask, resolving the contradiction between achieving high-resolution patterning and preventing electrical discharge
2Ease of manufacture
If the mask structure is simplified to reduce manufacturing complexity, then ease of manufacture is improved, but the ability to neutralize potential differences and prevent arcing is reduced
Solution Approach 1:
The mask structure is segmented into functional zones: the reflective film stack for optical performance, the absorptive film stack for pattern definition, and the conductive layer at the trench bottom for electrical neutralization. This segmentation allows each component to be optimized independently, maintaining manufacturing simplicity while incorporating the necessary arcing prevention functionality
Solution Approach 2:
The conductive layer is applied locally at the bottom of trenches where potential differences are most problematic, rather than coating the entire mask surface. This localized application maintains ease of manufacture by targeting only the critical areas needed for arcing prevention, while the rest of the mask structure remains simple and easy to fabricate
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
The solution effectively reduces arcing and particle discharge, enhancing the precision and reliability of the pattern transfer process in extreme ultraviolet (EUV) lithography, leading to improved manufacturing efficiency and accuracy of ICs.
Implementation Method 1
The conductive material neutralizes differences in potential that may occur along the bottom of the trench due to the photoelectric effect
Data Source
AI summary
In an embodiment, a photomask includes: a substrate over a first conductive layer, the substrate formed of a low thermal expansion material (LTEM); a second conductive layer over the first conductive layer; a reflective film stack over the substrate; a capping layer over the reflective film stack; an absorption layer over the capping layer; and an antireflection (ARC) layer over the absorption layer, where the ARC layer and the absorption layer have a plurality of openings in a first region exposing the capping layer, where the ARC layer, the absorption layer, the capping layer, and the reflective film stack have a trench in a second region exposing the second conductive layer.