Etching method and plasma processing apparatus
AssigneeTokyo Electron Limited
InventorsKoki CHINO, Hikoichiro SASAKI
Life of this patent
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Abstract
An etching method includes: (a) preparing a substrate including a silicon-containing film including a silicon oxide film and placed on a substrate support provided in a chamber; (b) supplying a processing gas containing a tungsten hexafluoride gas, a gas containing carbon and fluorine, and an oxygen-containing gas into the chamber; and (c) generating plasma from the processing gas to etch the silicon-containing film. (c) includes periodically applying a negative DC voltage to the substrate support.
Claims19
A plasma processing apparatus comprising:
- a chamber;
- a substrate support provided in the chamber;
- a gas supply configured to supply a processing gas including tungsten hexafluoride gas into the chamber;
- a plasma generator configured to generate plasma from the processing gas in the chamber;
- and
- a bias power supply configured to, when the plasma is generated to etch a silicon-containing film on a substrate disposed on the substrate support, periodically apply, as an electric bias, a DC voltage having a duty ratio of 5% or more and 40% or less to the substrate support at a time interval that is a reciprocal of a bias frequency of 100 kHz or more and 1 MHz or less.
A plasma processing apparatus comprising:
- a chamber;
- a substrate support provided in the chamber;
- a gas supply configured to supply a processing gas including tungsten hexafluoride gas into the chamber;
- a plasma generator configured to generate plasma from the processing gas in the chamber;
- and
- a bias power supply configured to, when the plasma is generated to etch a silicon-containing film on a substrate disposed on the substrate support, periodically apply an electric bias to the substrate support, thereby substituting a part of silicon atoms in the silicon-containing film with tungsten atoms on a bottom surface of a recess formed in the silicon-containing film by the etching, and etching the silicon-containing film in which the part of silicon atoms are substituted with the tungsten atoms.
A plasma processing apparatus comprising:
- a chamber;
- a substrate support provided in the chamber;
- a gas supply configured to supply a processing gas including tungsten hexafluoride gas into the chamber;
- a plasma generator configured to generate plasma from the processing gas in the chamber;
- and
- a bias power supply configured to periodically apply an electric bias to the substrate support,
- wherein (a) the gas supply supplies the processing gas into the chamber, and
- (b) the plasma generator generates the plasma from the processing gas, thereby etching a silicon-containing film on a substrate disposed on the substrate support,
- in (b), the bias power supply periodically applies an electric bias to the substrate support,
- the silicon-containing film includes a stacked film including a silicon oxide film and a silicon nitride film,
- in (b), in order to etch the silicon nitride film, the bias power supply sets a bias frequency, which is a reciprocal of a time interval during which the electrical bias is applied to the substrate support, to a first frequency, and
- in (b), in order to etch the silicon oxide film, the bias power supply sets the bias frequency to a second frequency higher than the first frequency.
Dependencies are inferred from the claim text.