III–V site-controlled quantum dots on Si patterned by nanoimprint lithography

• We have used nanoimprint lithography to fabricate large-area hole patterns on Si.
• We could remove surface oxides with protocols compatible with III–V MBE.
• Site-controlled InAs/GaAs/Si quantum dot arrays were grown by MBE.
• We have reached a perfect selectivity for growth in the holes.

We have successfully grown regular arrays of InAs/GaAs quantum dots on patterned Si substrates. Thanks to the capability of nanoimprint lithography, we were able to obtain uniform patterns extended over some cm2 areas, with periods of 300 nm. Ex-situ and in-situ treatments of the surface allowed us to completely remove any residual oxides prior to growth without the use of hydrogen beams, at temperatures compatible with standard III–V molecular beam epitaxy. The growth protocol was optimized in order to obtain a perfect selectivity of InAs/GaAs nanostructures in the holes, without any deposition on the planar areas.