Patent ID: 9548214
Date: 2017-01-17
CPC Classifications: H01J,H01L

Claim:
1. A plasma etching method of introducing a processing gas containing fluorocarbon into a processing vessel in which a processing target object is provided; applying a first high frequency power for excitation of the processing gas into plasma and a second high frequency power for attraction of ions to the processing target object, which has a frequency lower than a frequency of the first high frequency power, between electrodes within the processing vessel; and etching the processing target object by the generated plasma, the plasma etching method comprising: a first process of applying, while applying the first high frequency power to the electrode, the second high frequency power to the electrode while switching ON/OFF of the second high frequency power cyclically; and a second process of applying, while applying the first high frequency power to the electrode, the second high frequency power to the electrode while maintaining the second high frequency power ON continuously, wherein the processing target object includes a multilayered film in which a first film and a second film having different permittivities are alternately stacked on top of each other; and a mask formed on the multilayered film, the first process and the second process are alternately performed such that deposits, which are originated from the processing gas and stuck to an inner surface of a hole or a groove formed by the etching, are uniformly formed from a vicinity of a top portion of the hole or the groove to a bottom portion of the hole or the groove, and a first period during which the first process is performed and a second period during which the second process is performed are set to have a range from 10 sec to 60 sec and have a range 10 sec to 60 sec, respectively.