Patent ID: 9048191
Filing Date: 2015-06-02
Classification: H01J,H01L

Abstract:
1. A plasma etching method that involves supplying an etching gas containing an oxygen gas and a sulfur fluoride gas at a predetermined flow rate into a processing chamber that accommodates a processing substrate, which includes a silicon layer and a resist layer that is arranged into a predetermined pattern on the silicon layer, and etching the silicon layer with plasma generated from the etching gas supplied to the processing chamber using the resist layer as a mask, the method comprising: a first step of etching the silicon layer while a flow ratio of the oxygen gas to the sulfur fluoride gas is adjusted to a first flow ratio; a second step of etching the silicon layer while decreasing a flow rate of the oxygen gas to decrease the flow ratio of the oxygen gas to the sulfur fluoride gas to a second flow ratio, which is lower than the first flow ratio; and a third step of etching the silicon layer while the flow ratio of the oxygen gas to the sulfur fluoride gas is adjusted to the second flow ratio, wherein