Patent ID: 8142852

Claim:
A device manufacturing method comprising: supplying liquid using a liquid supply system to a space between a projection system of a lithographic apparatus and a substrate from a tank via a flow restriction; supplying liquid to the tank so as to maintain a liquid level within a certain height range relative to the flow restriction, wherein the height range is h ±Δh, where h is in the range of from 1 to 10 m and Δh is in the range of from 0.05 to 20 mm; supplying a peroxide solution to the liquid supply system to clean at least the liquid supply system, the liquid supply system having a channel to an outlet to the space; exposing liquid in the channel to UV radiation from a UV-lamp at a point in the channel downstream of an input of the peroxide solution to the channel but upstream of the space; and projecting a patterned beam of radiation, using the projection system, onto a substrate through the liquid.