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US 2022/0187698 A1Published application
Method and apparatus to improve euv mask blank flatness
AssigneeApplied Materials, Inc.
InventorsVibhu Jindal, Sanjay Bhat, Wen Xiao, Vinodh Ramachandran
Life of this patent
Estimating the term…
Abstract
Apparatus and methods for improving flatness of extreme ultraviolet (EUV) mask blanks are disclosed. The apparatus and methods may utilize one or more of heating the backside and/or the front side of the EUV mask blank and a cooling system. Interfacial layers of the EUV mask blank are selectively heated, resulting in improved flatness of the EUV mask blanks.
Claims20
A method of manufacturing an extreme ultraviolet (EUV) mask blank comprising:
- heating the EUV mask blank comprising a multilayer stack which reflects EUV radiation on a front side of a substrate having the front side and a backside opposite the front side, the multilayer stack comprising a number X of reflective layer pairs, wherein an x is in a range of from 30 to 60;
- selectively heating a number Y reflective layer pairs adjacent to the substrate to a first temperature, wherein Y is an integer in a range of from 1 to 20;
- and
- maintaining reflective layer pairs above the Y reflective layer pairs at a second temperature that is less than the first temperature.
1 more element
An apparatus configured to selectively heat a portion of an EUV mask blank, the apparatus comprising:
- a chamber including a pedestal configured to support the EUV mask blank;
- an EUV mask blank handling fixture including a carrier base and a top shield configured to hold the EUV mask blank on the pedestal during a selective heating process in the chamber;
- lift pins configured to raise the top shield above the EUV mask blank during the selective heating process and a pad configured to separate the EUV mask blank from the carrier base during the selective heating process;
- and
- a light source positioned and configured to direct light toward the pedestal and to selectively heat a first portion of the EUV mask blank to a first temperature while maintaining a second portion of the EUV mask blank at a second temperature lower than the first temperature.
2 more elements
Dependencies are inferred from the claim text.