Abstract:
Pellicles or films are disclosed that are suitable for use as protective covers for EUV device lithography reticles (patterning structures). The pellicles pass radiation of wavelength 5nm to 20nm whilst acting as a barrier to particulate deposits on reticles, which would otherwise lead to defects in devices patterned using the reticles. Also disclosed are reticle assemblies and lithographic apparatus including such pellicles, as well as methods for forming the pellicles. The pellicles may have a multilayer configuration, with the central region having two or more layers of silicon alternating with layers of the refractory material. Silicon oxide or nitride may be used as an interfacial layer for adhesion/anti-diffusion between the silicon and the refractory material. The pellicles are capable of self-support when tensioned over a reticle, without need of a support grid, even when sufficiently thin to permit high EUV transmissivity.
Abstract:
A multilayer mirror (1) for use in device lithography. The multilayer mirror configured to reflect and/or pattern radiation having a wavelength in the range of about 6.4nm to about 7.2nm. The multilayer mirror has a plurality of alternating layers (4, 6) of materials. The plurality of alternating layers of materials include first layers of materials and second layers of materials. The second layers have a higher refractive index for the radiation than the first layers. The materials of the first layers and the materials of the second layers are mutually chemically unreactive at an interface (7) therebetween at temperatures less than 300 °C. This may allow the mirrors to have a narrow boundary region of intermingled materials from alternating layers between the layers, for example of 0.5 nm or less in width, which may improve sharpness of the boundary region and improve reflectivity.