Abstract: The invention is directed to an etching method. The etching method comprises steps of providing a material layer having a patterned hard mask layer formed thereon and then performing a first dry etching process by using the patterned hard mask layer as a mask, wherein a first power mode of the first dry etching process is a pulse mode and the first dry etching process is performed for a first process time. A second dry etching process is performed by using the patterned hard mask layer as a mask, wherein a second power mode of the second dry etching process is a continued wave mode and the second dry etching process is performed for a second process time, and the ratio of the first process time to the second process time is about 0.1˜2.0.

Abstract: An inductively-coupled plasma etch apparatus and a feedback control method thereof are provided. A voltage/current measuring device is connected to an electrostatic chuck of the plasma etching apparatus, so as to measure the RF current, voltage and the phase angle between them on the electrostatic chuck. The ion current and the RF bias voltage are obtained by calculation of the RF current, voltage and the phase angle. Finally, using the obtained ion current and the RF bias voltage to feedback control the RF power generator in order to achieve the desired plasma status.