Abstract
The purpose of this research is to study HfO2 and Si etch characteristic in inductivity coupled plasma etcher. Operating parameters are plasma source power, rf peak voltage, Cl2/Ar gas flow rate, and chamber pressure. The influence of those parameters on etch rate and selectivity are investigated., The impedance meter connected to the electrostatic chuck is used to measure rf peak voltage on electrostatic chuck. The controller is designed to feedback control the rf peak voltage, which is used to replace the bias power as the controlled variable. HfO2 etch rate almost does not vary when Ar % is changed. In high Ar % plasma, HfO2 surface has higher roughness, the reason is due to the effect of high ion flux and low chemical reactions. Increasing plasma source power, rf peak voltage, total gas flow rate and reducing chamber pressure can increase HfO2/Si etch selectivity. However, in Cl2/Ar plasma, the etch selectivity of HfO2/Si can not be higher than 1.