Patent · US Active

Reflective photomask and reflection-type mask blank

US10031409B2 · kind B2 · utility

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0References

24Claims

0Family size

Assignee

ADVANCED MASK TECHNOLOGY CENTER GMBH & CO. KG · DE

Inventors

Markus Bender · Dresden, DE
Thorsten Schedel · Dresden, DE

Key dates

Filing date	Jun 10, 2016
Grant date	Jul 24, 2018
Priority date	—
Expiry date	Aug 18, 2036

Classification

Technology area (CPC G)Physics
CPC primaryG03F1/38
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A reflective photomask includes a substrate with a substrate layer of a low thermal expansion material. The substrate layer includes a main portion of a first structural configuration and an auxiliary portion of a second structural configuration of the low thermal expansion material. The auxiliary portion is formed in a frame section surrounding a pattern section of the substrate. A multilayer mirror is formed on a first surface of the substrate. A reflectivity of the multilayer mirror is at least 50% at an exposure wavelength below 15 nm. A frame trench extending through the multilayer mirror exposes the substrate in the frame section. The auxiliary portion may include scatter centers for out-of-band radiation.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.