LASER PRODUCED PLASMA EUV LIGHT SOURCE

Methods and apparatus for producing EUV from plasma are disclosed. The apparatus includes a plasma generating system comprising a source of target material droplets and a laser producing a beam irradiating the droplets at an irradiation region. The plasma produces EUV radiation, wherein the droplet source comprises a nozzle having an orifice configured for ejecting a fluid and a sub-system having an electro-actuable element producing a disturbance in the fluid to cause at least some of the droplets to coalesce prior to being irradiated. The electro-actuable element is coupled to nozzle using an adhesive that has a high modulus at the nozzle operating temperature. Improvements also include tuning the nozzle assembly to more closely match the modulation waveform frequency with one of the resonance frequencies of the nozzle assembly by optimizing one of a mass, a shape, or material composition of at least one component in the nozzle assembly.