Utke, Ivo; Jenke, Martin G.; Röling, Christian; Thiesen, Peter H.; Iakovlev, Vladimir; Sirbu, Alexei; Mereuta, Alexandru; Caliman, Andrei; Kapon, Eli
Nanoscale 3 (2011)
Local electron triggered reactions of functional surface adsorbates were used as a maskless, dry, and minimally invasive nanolithography concept to stabilize the polarisation of individual vertical cavity surface emitting lasers (VCSELs) on a wafer in a post-processing step. Using a 30 keV focused electron beam of a scanning electron microscope and injecting volatile organo-metallic (CH3)2Au(tfa) molecules, polarisation gratings were directly written on VCSELs by dissociating the surface adsorbed molecules. The electron triggered adsorbate dissociation resulted in electrically conductive Au-C nano-composite material, with gold nanocrystals embedded in a carbonaceous matrix. A resistivity of 2500 cm was measured at a typical composition of 30 at.% Au. This material proved successful in suppressing polarisation switching when deposited as line gratings with a width of 200 nm, a thickness of 50 nm, and a pitch of 500 nm and 1m. Refractive index measurements suggest that the optical attenuation by the deposited Au-C material is much lower than by pure Au thus giving a low emission power penalty while keeping the polarisation stable. © 2011 The Royal Society of Chemistry.