Photon sources for lithography and metrology Photon sources enable the extension of lithography and metrology technologies for continued scaling of circuit elements and therefore are the key drivers for the extension of Moores law. This comprehensive 28 chapter volume is the authoritative reference on photon source technology and includes contributions from leading researchers and suppliers in the photon source field. It is intended to meet the needs of both practitioners of the technology and readers seeking a thorough introduction to EUV photon sources and their applications. Topics include a state of the art overview and in depth explanation of photons source requirements fundamental atomic data and theoretical models of EUV sources based on discharge produced plasmas (DPPs) and laser produced plasmas (LPPs) a description of prominent DPP and LPP designs and other technologies for producing EUV radiation at 13.5 nm. Additionally this volume contains detailed descriptions of 193 nm excimer lasers UV lamps and laser driven plasma sources for UV photons all of which power many current lithography and metrology tools. CO2 lasers and 1 um Nd YAG lasers used for pre pulse in Sn LPP EUV sources are also covered. Alternative photon sources for 13.5 nm lithography and metrology such as high harmonic generation (HHG) and synchrotrons along with their usage as a metrology tool are discussed; and potential future photon sources such as free electron lasers (FELs) solid state 2 um thulium lasers and 1 um Nd YAG lasers are described. Additional topics include EUV source metrology plasma diagnostics of EUV plasmas grazing and normal incidence collector optics for plasma sources debris mitigation and mechanisms of component erosion in EUV sources