Preparation method of semiconductor nano circular ring

The invention discloses a preparation method of a semiconductor nano circular ring. The method is characterized by firstly coating positive photoresist on a semiconductor substrate, then, based on the principle of Poisson diffraction, exposing the photoresist by a circular mask with a micron diameter to obtain circular ring shaped photoresist and then carrying out plasma etching on the substrate under the protection of the circular ring shaped photoresist to form a circular ring shaped structure with nano-sized wall thickness on the surface of the substrate. The nano-sized circular ring shaped structure is prepared by adopting micron-sized photoetching equipment and the micron-sized circular mask, so dependence on the advanced photoetching technology is overcome, thus effectively loweringthe preparation cost of the nano-sized circular ring shaped structure.