Microfabrication of sharp blazed gratings by a two-step height amplification process based on soft and deep X-ray lithography

We describe a scheme for the fabrication of sharp blazed gratings involving two cascaded steps of X-ray lithography (XRL) with electroplating (EP) steps interposed. The adopted iterative scheme enables the amplification by two orders of magnitude of the height of high-resolution structures of an original X-ray mask produced by Electron Beam Lithography (EBL), while minimizing the loss of lateral resolution. Nickel structures of up to 200 μm in height with blazed grating profile were obtained with <500 nm resolution details. The described approach is suitable for the fabrication of nickel structures, to be used in particular as master tools in hot embossing processes, in a broad range of optical applications requiring non-binary microstructures. © 2013 Elsevier B.V.