Plasma Etching Method
AssigneeTokyo Electron Limited
InventorTetsuya Nishizuka
Life of this patent
Estimating the term…
Abstract
This invention relates to a method for conducting an etching process which uses a plasma of a process gas. This etching process is conducted on a wafer W including a substrate 101, an underlying film 102, 103 formed on the substrate, and a film 104 to be etched that is formed on the underlying film. A main etching gas formed up of a chlorine-containing gas and an oxygen-containing gas, and a nitrogen-containing gas are used as the process gas. In this etching method, etching is conducted under a condition that an N2+/N2 intensity ratio of N2+ to N2, derived from emission spectra of the plasma, is at least 0.6.
Claims16
An etching method using a plasma of a process gas to carry out an etching process for an object including a substrate, an underlying film formed on the substrate, and a film to be etched that is formed on the underlying film, wherein:
- a main etching gas and a nitrogen-containing gas are used as the process gas to etch the film under a condition that an N2+/N2 intensity ratio of N2+ to N2, derived from emission spectra of the plasma, is at least 0.6.
An etching method using a plasma of a process gas to carry out an etching process for an object including a substrate, an underlying film made of a silicon-containing film formed on the substrate, and a film to be etched that is made of a tungsten-containing film formed on the underlying film, wherein:
- a chlorine-containing gas, an oxygen-containing gas, and a nitrogen-containing gas are used as the process gas to etch the film under a condition that an N2+/N2 intensity ratio of N2+ to N2, derived from emission spectra of the plasma, is at least 0.6.
An etching apparatus using a plasma of a process gas to carry out an etching process for an object including a substrate, an underlying film formed on the substrate, and a film to be etched that is formed on the underlying film, the apparatus comprising:
- a processing vessel configured to accommodate the object;
- a gas supply system configured to supply a main etching gas and a nitrogen-containing gas as the process gas into the processing vessel while controlling respective flow rates of the gases;
- a plasma generating system configured to generate the plasma in the processing vessel;
- an emission spectrum detection system configured to detect emission spectra of the plasma of the process gas generated in the processing vessel;
- and
- a controller configured to control the gas supply system and the plasma generating system to obtain plasma-generating conditions under which an N2+/N2 intensity ratio of N2+ to N2, derived from the emission spectra of the plasma detected by the detection system, is at least 0.6.
An etching apparatus using a plasma of a process gas to carry out an etching process for an object including a substrate, an underlying film made of a silicon-containing film formed on the substrate, and a film to be etched that is made of a tungsten-containing film formed on the underlying film, the apparatus comprising:
- a processing vessel configured to accommodate the object;
- a gas supply system configured to supply a chlorine-containing gas, an oxygen-containing gas, and a nitrogen-containing gas as the process gas into the processing vessel while controlling respective flow rates of the gases;
- a plasma generating system configured to generate the plasma in the processing vessel;
- an emission spectrum detection system configured to detect emission spectra of the plasma of the process gas generated in the processing vessel;
- and
- a controller configured to control the gas supply system and the plasma generating system to obtain plasma-generating conditions under which an N2+/N2 intensity ratio of N2+ to N2, derived from the emission spectra of the plasma detected by the detection system, is at least 0.6.
A computer-readable storage medium storing a control program for executing an etching method using a plasma of a process gas to carry out an etching process for an object including a substrate, an underlying film formed on the substrate, and a film to be etched that is formed on the underlying film, the method being carried out by using a main etching gas and a nitrogen-containing gas as the process gas to etch the film under a condition that an N2+/N2 intensity ratio of N2+ to N2, derived from emission spectra of the plasma, is at least 0.6.
Dependencies are inferred from the claim text.