Multilayer reflective mask

A method for fabricating a reflective mask, comprising the steps of:

• coating a substrate with a first reflective material having a first set of optical characteristics;
• selectively removing portions of the first reflective material to expose openings to the substrate;
• coating the substrate openings and the first reflective material with a second reflective material having a second set of optical characteristics;
• and
• planarizing the reflective materials such that they are substantially co-planar.

A method for fabricating a reflective mask, comprising the steps of:

• coating a planar substrate with a first reflective material having a first set of optical characteristics;
• selectively removing portions of the first reflective material to expose openings to the substrate;
• coating the substrate openings and the first reflective material with a second reflective material having a second set of optical characteristics;
• selectively removing portions of the second reflective material to expose openings to the substrate and the first reflective material;
• coating the openings to the transparent substrate and the first and second reflective materials with a third reflective material having a third set of optical characteristics;
• and
• planarizing a top surface of the reflective materials such that they are substantially co-planar.

A reflective lithographic mask for use in forming semiconductor devices, the mask comprising:

• a substrate;
• a plurality of first reflective material regions formed on the substrate and having a first set of optical characteristics;
• a plurality of second reflective material regions formed on the substrate between the first reflective material regions and having a second set of optical characteristics;
• and
• wherein each of the plurality of first and second material regions cooperate to form desired patterns when radiation reflected from them is focussed on a semiconductor substrate.

A reflective lithographic mask for use in forming semiconductor devices, the mask comprising:

• a substrate;
• a plurality of first reflective material regions formed on the substrate and having a first set of optical characteristics;
• a plurality of second reflective material regions formed on the substrate between the first reflective material regions and having a second set of optical characteristics;
• a plurality of third reflective material regions formed on the substrate between the first and second reflective material regions and having a third set of optical characteristics;
• and
• wherein each of the plurality of first, second and third material regions cooperate to form desired patterns when radiation reflected from them is focussed on a semiconductor substrate.