Method for manufacturing nanoscale structures in transition metal layers

摘要

In most transition metals, steeply profiled nanoscale structures can not easily be obtained by dry etching, due to the redeposition of the etch products. An alternative method is presented here, which comprises the deposition of a plating base, electron-beam writing of nanoscale structures in negative tone hydrogen silsesquioxane resist, and electroplating of the desired metal layer between the resist lines. This method is used for making transmittive and reflective masks, alignment marks, and other optical gratings, consisting of features down to 40 nm wide that are embedded in transition metal layers. These gratings can, e.g., be applied in extreme-UV lithographic sensors. More generally, other devices, e.g., magnetic recording heads, can also be manufactured using this technology.