PLASMA ETCHING METHOD

摘要

A wafer (W) is placed on a lower electrode (106) disposed in a processing chamber (102) of an etching device (100), with a gas containing C4F8 introduced into the chamber (102). A controller (112) applies a 27 MHz power from a plasma generating power supply (120) to an upper electrode (114), and an 800 kHz power from a biasing power supply (108) to the lower electrode (106) intermittently. When a biasing power is on, an insulating film (202) consisting of SiO2 of the wafer (W) is etched, and, when it is off, a polymer (protecting film) (208) is formed on a photoresist film (206). The above method can enhance the selectivity of the insulating film with respect to the photoresist film to form a contact hole in a preset shape.