Investigating the etch Performance of Zirconium-Based Photoresist for Direct Silicon Oxide Etching

In this work we investigated one step direct silicone oxide etching using a novel zirconium based photoresist instead of the multilayer method commonly used in the semiconductor industries, It’s cost and time effective and also minimizes the chances of error. After optimizing important parameters including Pressure, Bias power and ICP power and other etch conditions we obtained selectivity of resist to silicon oxide of over 18.8 to 1 with 97% resist still left on the surface. This is much higher than the selectivity’s of 1 to 4 reported in the literature for the etches of silicon oxide using conventional e-beam resists. The etch depth obtained after 180 seconds is about 866 nm with an etch rate up to 288 nm/min. Overall, our results suggest that a zirconium resist could be used in a simplified process without a hard mask or trilayer setup and still get deep etch depths. This may be an opportunity for useful process simplification.