Lithographic apparatus, device manufacturing method and substrate holder

Lithographic apparatus, device manufacturing method and substrate holder

A substrate holder has burls having a height not less than 100 μm and at least 10 vacuum ports arranged within a central region extending to a radius of two thirds the radius of the substrate. Thereby concave wafers can be reliably clamped by generating an initial vacuum in a central region which ex...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Van Ballegoij, Robertus Nicodemus Jacobus, Cuijpers, Martinus Agnes Willem, Meijers, Pieter Johannes Gertrudis, Van Nunen, Gerardus Petrus Matthijs, Ottens, Joost Jeroen
Format: Patent
Sprache:eng
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:A substrate holder has burls having a height not less than 100 μm and at least 10 vacuum ports arranged within a central region extending to a radius of two thirds the radius of the substrate. Thereby concave wafers can be reliably clamped by generating an initial vacuum in a central region which exerts a clamping force tending to flatten the wafer and allowing the initial vacuum to deepen until the wafer is fully clamped.