Patent ID: 7140233
Filing Date: 2006-11-28
Classification: G03F

Abstract:
1. 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 wherein said measurement nozzle shroud includes: 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.