Magnification inferred curvature for real-time curvature monitoring

Abstract The in situ and real-time measurement of curvature changes of optically reflecting surfaces is a key element to better control bottom-up fabrication processes in the semiconductor industry, but also to follow or adjust mirror deformations during fabrication and use for space or optics indus...

Full description

Saved in:
Bibliographic Details
Main Authors: Alexandre Arnoult, Jonathan Colin
Format: article
Language:EN
Published: Nature Portfolio 2021
Subjects:
R
Q
Online Access:https://doaj.org/article/70043f881fba4b61bd17f230cd26d878
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract The in situ and real-time measurement of curvature changes of optically reflecting surfaces is a key element to better control bottom-up fabrication processes in the semiconductor industry, but also to follow or adjust mirror deformations during fabrication and use for space or optics industries. Despite progresses made in the last two decades thanks to laser deflectometry-based techniques, the community lacks an instrument, easy to use, robust to tough environments and easily compatible with a large range of fabrication processes. We describe here a new method, called magnification inferred curvature (MIC), based on the determination of the magnification factor of the virtual image size of a known object created by a reflecting curved surface (the substrate) acting as a spherical mirror. The optical formalism, design, and proof of concept are presented. The precision, accuracy, and advantages of the MIC method are illustrated from selected examples taken from real-time growth monitoring and compared with state-of-the-art laser deflectometry-based instruments.