Digital etching study and fabrication of fine Si lines and dots

Abstract

For the goal of damage-free microfabrication, digital etching in which one or a few atomic layers are removed with minimum reaction energy has been studied. The atomic layer etching of Si(100) was achieved by the precise control of F atom adsorption. To evaluate sidewall etching damage, conductance for lines fabricated on SIMOX was measured at 4.2 K. Lines fabricated by the digital method exhibited no appreciable damage, contrary to the 0.2 μm line fabricated by magnetron reactive ion etching. In a 0.1 μm line subjected partly to an exposure of hydrogen plasma, non-linearity in the I–V relationship was observed at 4.2 K. The fabrication of Si dots with 20–100 nm diameter was successfully achieved by both an adequate electron beam dose and Ar + irradiation time. Photoluminescence measurements revealed that a significant plastic deformation was generated in oxidized Si dots on SIMOX substrate.