Method for large-area preparation of micro-nano convex ball lens array

A method for large-area preparation of a micro-nano convex ball lens array by combining electron-beam lithography (EBL) and reactive ion etching (RIE) comprises the following steps of 1 cleaning the surface of a diamond and evaporating adhesion layer metal, 2 spin-coating an HSQ layer on the surface of a diamond sample evaporated with the adhesion layer metal and performing prebaking, 3 exposing the HSQ layer on the surface of the diamond sample in an EBL system, 4 performing development and fixation on the exposed HSQ layer, 5 adopting the RIE to remove the adhesion layer metal around a periodic cylindrical silicon oxide mask, 6 adopting the RIE to form a periodic convex ball lens array structure. The method is simple and flexible, preparation of the large-area convex ball structure on the surface of the diamond can be achieved, and the method is potentially applied to diamond NV color center single-photon devices and the like.