A single-step electron beam lithography of buried nanostructures using cathodoluminescence imaging and low temperature.

We report a new electron beam lithography process using the cathodoluminescence properties of semiconductors to visualize nanostructures buried underneath the resist and to subsequently write the pattern associated with these nanostructures. This single-step process could be used, for example, to make electrical contacts to nanowires (as illustrated in this work) or to design a photonic crystal resonator centered on a single quantum dot. Fabrication speed and positioning accuracy are significantly increased as compared to the standard process since no alignment marks and the mapping step of the nanostructures with respect to these marks are needed. We show also that low temperature (down to 5 K) could be used to improve the observation of the nanostructures through the resist while keeping very good spatial resolution.