EUV light source optical elements

Abstract

Apparatus and methods are disclosed for forming plasma generated EUV light source optical elements, e.g., reflectors comprising MLM stacks employing various binary layer materials and capping layer(s) including single and binary capping layers for utilization in plasma generated EUV light source chambers, particularly where the plasma source material is reactive with one or more of the MLM materials.

1 . A plasma produced EUV light source reflector element comprising: 
 a multilayer mirror stack comprising a plurality of binary layers each comprising a spacer layer comprising a spacer material alloy and an absorber layer comprising an absorber material alloy; and    a top diffusion barrier layer comprising a material selected from the group comprising nitrides, borides and carbides; and    the top diffusion layer lying on top of the absorber material alloy;    a plasma produced EUV light source reflector element comprising:    a multilayer mirror stack comprising a plurality of binary layers and a capping layer comprising a lithium diffusion barrier layer and a halogen etching barrier layer;    the capping layer comprising a material comprising lithium.