Patent ID: 6767838
Filing Date: 2004-07-27
Classification: C23F,H01J,H01L

Abstract:
A method of etching a sample having a gate electrode film and a film underlying the gate electrode film and provided on a Si substrate, having a pattern in which a minimum feature size of the gate electrode film is 0.5 &mgr;m or smaller and a thickness of the underlying film is 6 nm or smaller, and in which the gate electrode film is etched to form a fine pattern comprising lines and spaces having a wide part and a narrow part, comprising the steps of:arranging the sample on a stage provided in a chamber; continuously supplying an etching gas into the chamber and continuously generating a plasma from the etching gas during etching of the gate electrode film; applying an rf bias at a frequency of 100 kHz or higher to the stage independently of the generation of the plasma; and on-off modulating the rf bias at a frequency of 100 Hz to 10 kHz during etching of the gate electrode film.