Abstract:Quartz tapered sidewall etching with two-step etching method has been studied based on photoresist modification technology. Firstly, the vertical sidewall of the photoresist was modified to a tapered profile using Ar/O2/CF4 plasma. Then the transfer of the tapered sidewall of the photoresist to quartz is carried out in the same etching chamber. The influence of gas flow, etching power, temperature and etching time on the etching rate, selectivity and morphology in the photoresist modification process was studied in detail. Through optimizing the process parameters, tapered quartz profile with a sidewall angle of 60°and a smooth surface was prepared. This work provides a helpful guideline for tapered sidewall etching of SiO2 as well as other materials.