Diffuser plate and method of making same

An electromagnetic radiation diffuser comprising:

• a substrate having a first and a second surface, said first surface having a structure with a three dimensional profile of individual grid units;
• a reflective coating formed on said first surface that conforms to said structure and diffusely reflects extreme ultraviolet radiation;
• and
• an absorptive grating formed over said reflective coating wherein said absorptive grating absorbs a first portion of the electromagnetic radiation, while a second portion of the electromagnetic radiation passing through spaces between said absorptive grating is diffusely reflected by said reflective coating.

A method for making an electromagnetic radiation diffuser on a substrate, comprising:

• (a) fabricating in a first surface of the substrate a three dimensional profile of individual grid units;
• (b) forming a reflective coating over said three dimensional profile that conforms to said three dimensional profile;
• and
• (c) forming an absorptive grating over said reflective coating.

A lithography system comprising:

• an electromagnetic radiation source;
• an electromagnetic radiation diffuser positioned at a first optical plane, said diffuser having a substrate with a three dimensional profile of individual grid units that are covered by a reflective coating that conforms to said substrate, wherein said reflective coating is further covered by an absorptive grating for absorbing a first portion of said electromagnetic radiation, while a second portion of said electromagnetic radiation passing through spaces between said absorptive grating is diffusely reflected by said reflective coating;
• and
• an electromagnetic radiation sensor positioned at a second optical plane;
• wherein electromagnetic radiation incident on said diffuser is diffusely reflected and received at said sensor.