Method of imaging a mask pattern on a substrate by means of EUV radiation, and apparatus and mask for performing the method
AssigneeU.S. Philips Corporation
InventorsJosephus J. M. Braat, Jan Verhoeven
Life of this patent
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Abstract
An EUV radiation source unit (10) for use in a lithographic projection apparatus to illuminate a mask pattern (22) which is to be projected on a substrate (W) comprises an electron source (12) and a medium in which the electrons of the source generate EUV Cherenkov radiation (PB). The wavelengths of the Cherenkov radiation and the multilayer structure of the mirrors (31-34) of the projection system (30) are adapted to each other, so that these mirrors show a maximum reflectivity. The medium forms part of the mask (MA) so that a mirror condenser system is no longer needed. In this way, an efficient transmission of radiation (PB) from the source to the substrate is obtained.
Claims6
A method of imaging, by means of EUV radiation, a mask pattern, present in a mask, in a radiation-sensitive layer provided on a substrate, using a mirror projection system, characterized in that use is made of an electron beam and of a medium in which Cherenkov EUV radiation is generated by electrons, and in that said medium is constituted by a layer of the mask.
A method of manufacturing devices comprising the steps of:
- providing at least one mask with a mask pattern representative of a structure layer of the device;
- imaging, by means of the EUV radiation, the said mask pattern onto at least one area of a substrate provided with a layer which is sensitive to the EUV radiation, in which area is a device is to be formed, the number of areas being equal to the number of devices to be formed in the substrate;
- developing and further processing the images on the substrate area to convert these image into a layer structure of the devices, and
- repeating these steps with at least one other pattern until the complete device structure is formed in the substrate,
- characterized in that for generating the EUV radiation use is made of an electron beam generator for bomdarding the mask with electrons and of a mask comprising a medium wherein Cherenkov radiation is generated upon bombardment with electrons.
Dependencies are inferred from the claim text.