Patent ID: 9330888
Filing Date: 2016-05-03
CPC Classification: H01J,H01L

Claim Text:
1. A dry etching method, comprising steps of: etching a first medium layer on a substrate in a reaction chamber by a first gas as a reaction gas with a first radiofrequency power level provided by a radiofrequency module; introducing a second gas into the reaction chamber while the radiofrequency module keeps working and exciting the second gas into a plasma with a second radiofrequency power level while the radiofrequency module keeps working, so that the plasma formed from the second gas is combined with particulate pollutants in the reaction chamber to form a dust plasma, and the particulate pollutants keep in a suspended state instead of falling onto the substrate after the first medium layer is etched; pumping down the reaction chamber to a vacuum; and etching a second medium layer on the substrate in the reaction chamber by a third gas as a reaction gas.