Patterned x-ray emitting target

An X-ray metrology system comprising:

• an X-ray source for generating an X-ray beam, said X-ray source including:
• an electron gun that is configured to generate an electron beam;
• and
• a patterned X-ray emitting target that comprises:
• an X-ray blocking mask that comprises one or more openings;
• one or more structural elements positioned below the X-ray blocking mask and comprising an X-ray generating structural element;
• the one or more structural elements comprise a top structural element;
• wherein the X-ray generating structural element is configured to (a) receive electrons of the electron beam that pass through the X-ray blocking mask, and (b) reflect, through the X-ray blocking mask, the X-ray beam;
• a sample holder positioning a sample having a periodic structure;
• a monochromator positioned between said X-ray source and said sample holder such that said X-ray beam travels from said X-ray source to said monochromator and then to said sample holder;
• and
• a detector for collecting at least a portion of an X-ray beam scattered by said sample.