Abstract: Provided is a plasma etching method increasing the selectivity of a silicon nitride film in relation to the silicon oxide film or silicon functioning as a base. In a plasma etching method setting a pressure in a processing container as a predetermined level by exhausting a processing gas while supplying the processing gas into the processing container, generating plasma by supplying external energy to the processing container, and setting a bias applied to a holding stage holding a substrate in the processing container as predetermined value to selectively etch the silicon nitride film with respect to a silicon and/or silicon oxide film, the processing gas includes a plasma excitation gas, a CHxFy gas, and at least one oxidizing gas selected from the group consisting of O2, CO2, CO, and a flow rate of the oxidizing gas with respect to the CHxFy gas is set to be 4/9 or greater.

Abstract: An etching method can improve etching accuracy as well as secure selectivity when forming a dummy gate of a fin-type field effect transistor. In the etching method, the dummy gate of a fin-type field effect transistor is formed with a target object. In the etching method, a gate material deposited between multiple fins is etched by using surface wave plasma. A pressure in the etching method is 50 mTorr (6.67 Pa) or more, a frequency of a power to be applied to a mounting table configured to mount thereon the target object is in a range of 10 Hz or more to 200 Hz or less, and the power is pulse-modulated such that a duty ratio as a ratio of an ON-time to a pulse cycle is 50% or less.

Abstract: An etching method can improve etching accuracy as well as secure selectivity when forming a dummy gate of a fin-type field effect transistor. In the etching method, the dummy gate of a fin-type field effect transistor is formed with a target object. In the etching method, a gate material deposited between multiple fins is etched by using surface wave plasma. A pressure in the etching method is 50 mTorr (6.67 Pa) or more, a frequency of a power to be applied to a mounting table configured to mount thereon the target object is in a range of 10 Hz or more to 200 Hz or less, and the power is pulse-modulated such that a duty ratio as a ratio of an ON-time to a pulse cycle is 50% or less.

Abstract: Provided is a plasma etching method increasing the selectivity of a silicon nitride film in relation to the silicon oxide film or silicon functioning as a base. In a plasma etching method setting a pressure in a processing container as a predetermined level by exhausting a processing gas while supplying the processing gas into the processing container, generating plasma by supplying external energy to the processing container, and setting a bias applied to a holding stage holding a substrate in the processing container as predetermined value to selectively etch the silicon nitride film with respect to a silicon and/or silicon oxide film, the processing gas includes a plasma excitation gas, a CHxFy gas, and at least one oxidizing gas selected from the group consisting of O2, CO2, CO, and a flow rate of the oxidizing gas with respect to the CHxFy gas is set to be 4/9 or greater.