Patent · US Active

Method for detecting particles on the surface of an object, wafer, and mask blank

US11555783B2 · kind B2 · utility

0Cited by

6References

17Claims

0Family size

Assignee

Carl Zeiss SMT GmbH · DE

Inventors

Oliver Beyer · Herford, DE
Michael Gerhard · Aalen, DE

Key dates

Filing date	Sep 27, 2019
Grant date	Jan 17, 2023
Priority date	—
Expiry date	Mar 13, 2041

Classification

Technology area (CPC G)Physics
CPC primaryG03F7/7085
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

A method for detecting deposited particles (P) on a surface (11) of an object (3, 14) includes: irradiating a partial region of the surface (11) of the object (3, 14) with measurement radiation; detecting measurement radiation scattered on the irradiated partial region, and detecting particles in the partial region of the surface of the object (3, 14) based on the detected measurement radiation. In the steps of irradiating and detecting, the surface (11) of the object (3, 14) has an anti-reflective coating (13) and/or a surface structure (15) for reducing the reflectivity of the surface (11) for the measurement radiation (9), wherein the particle detection limit is lowered due to the anti-reflective coating (13) and/or the surface structure (15). Also disclosed are a wafer (3) and a mask blank for carrying out the method.

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