EUV Projection Mirror Laser Heating for Overlay Error Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In extreme ultraviolet (EUV) exposure processes, small errors in EUV masks or mirrors can cause significant overlay errors during semiconductor manufacturing, leading to defects such as open defects and short circuits due to non-uniform heating and temperature distribution issues.
Innovation Solution
An EUV exposure apparatus and method that includes an EUV source, first illumination optics, projection optics, a laser source, and second illumination optics to generate and irradiate a laser beam onto mirrors within the projection optics, thereby heating them and minimizing overlay errors caused by non-uniform temperature distributions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If mirrors are used in projection optics for EUV exposure, then the exposure process can be performed with required wavelength, but non-uniform temperature distribution occurs in mirrors causing overlay errors
Solution Approach 1:
The laser heating apparatus performs preliminary heating of the mirrors before the actual EUV exposure process. By pre-heating the mirrors to a predetermined temperature, the system compensates for temperature changes that would occur during exposure, thereby maintaining uniform temperature distribution and preventing overlay errors caused by thermal deformation
Solution Approach 2:
The system changes the temperature parameter of the mirrors by applying controlled laser heating. The laser apparatus adjusts the temperature of the mirrors to a specific predetermined value, transforming the thermal state of the optical components to achieve uniform temperature distribution and eliminate thermal-induced overlay errors
2Temperature
If laser heating is applied to mirrors, then temperature distribution uniformity is improved, but device complexity increases
Solution Approach 1:
The laser heating apparatus is designed to serve multiple functions: it heats the mirrors to maintain uniform temperature distribution, and can also be used for calibration and measurement purposes. This multi-functionality reduces the need for separate dedicated heating systems, thereby limiting the increase in device complexity while achieving temperature uniformity
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 overlay errors by correcting temperature-related issues in mirrors, enhancing the precision and reliability of semiconductor device manufacturing by maintaining a uniform temperature distribution across the mirrors, thus improving the yield rate and reducing defects.
Implementation Method 1
a laser source configured to generate and output a laser beam, and second illumination optics configured to irradiate the laser beam onto at least one mirror included in the projection optics
Implementation Method 2
irradiate the laser beam onto at least one mirror included in the projection optics for heating the at least one mirror
Data Source
AI summary
Extreme ultraviolet (EUV) exposure apparatuses and methods, and methods of manufacturing a semiconductor device by using the exposure method, which minimize an error caused by a mirror in an EUV exposure process to improve an overlay error, are provided. The EUV exposure apparatus includes an EUV source configured to generate and output EUV, first illumination optics configured to transfer the EUV to an EUV mask, projection optics configured to project the EUV, reflected from the EUV mask, onto an exposure target, a laser source configured to generate and output a laser beam for heating, and second illumination optics configured to irradiate the laser beam onto at least one mirror included in the projection optics.