Source material dispenser for EUV light source

A source material dispenser for an EUV light source is disclosed that comprises a source material reservoir, e.g. tube, that has a wall and is formed with an orifice. The dispenser may comprise an electro-actuatable element, e.g. PZT material, that is spaced from the wall and operable to deform the wall and modulate a release of source material from the dispenser. A heat source heating a source material in the reservoir may be provided. Also, the dispenser may comprise an insulator reducing the flow of heat from the heat source to the electro-actuatable element. A method of dispensing a source material for an EUV light source is also described. In one method, a first signal may be provided to actuate the electro-actuatable elements to modulate a release of source material and a second signal, different from the first, may be provided to actuate the electro-actuatable elements to unclog the orifice.