Immersion lithography proximity sensor having a nozzle shroud with flow curtain
AssigneeASML Holding N.V.
InventorHerman Vogel
Life of this patent
Estimating the term…
Abstract
The present invention is directed to an immersion lithography proximity sensor having a nozzle shroud with a flow curtain. The immersion lithography proximity sensor includes a shroud that affixes to the nozzle. A plenum is located inside the shroud that holds a shroud liquid, which is fed into the plenum through one or more intake holes. The shroud liquid is emitted out through a series of openings, such as holes or slots, along a bottom surface of the shroud in a direction away from the nozzle. The shroud liquid that is emitted forms a curtain around the nozzle to prevent cross currents from impacting the flow of liquid out of the nozzle.
Claims5
An immersion lithography proximity sensor for sensing a difference between a reference surface standoff and a measurement surface standoff, comprising:
- a junction that divides liquid input into the immersion lithography proximity sensor into a reference channel and a measurement channel;
- a reference nozzle at an end of the reference channel, whereby liquid exits the reference channel through the reference nozzle and travels across a reference standoff to impinge upon a reference surface;
- a measurement nozzle at an end of the reference channel, whereby liquid exits the measurement channel through the measurement nozzle and travels across a measurement standoff to impinge upon a measurement surface;
- a measurement nozzle shroud affixed to said measurement nozzle that emits a shroud liquid in a direction away from the flow of liquid from said measurement nozzle, wherein said measurement shroud substantially circumscribers said measurement nozzle;
- and
- a measurement device coupled between the reference and measurement channels for sensing the flow of liquid therebetween, whereby, the differences in standoffs between the reference and measurement surfaces can be sensed at a high sensitivity.
Dependencies are inferred from the claim text.