Plasma generation method, cleaning method, and substrate processing method
AssigneeTokyo Electron Limited
InventorsHiroshi Kannan, Noboru Tamura, Kazuya Dobashi
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Abstract
A plasma generation method in a toroidal plasma generator that includes a gas passage having a gas entrance and a gas outlet and forming a circuitous path and a coil wound around a part of the gas passage includes the steps of supplying a mixed gas of an Ar gas and an NF3 gas containing at least 5% of NF3 and igniting plasma by driving the coil with a high-frequency power, wherein the plasma ignition step is conducted under a total pressure of 6.65-66.5 Pa.
Claims20
A cleaning method for cleaning an interior of a processing vessel by plasma-excited radicals of a cleaning gas under a first pressure, said method comprising the steps of:
- introducing a mixed gas of a diluting gas and said cleaning gas to a plasma generator under a second pressure lower than said first pressure;
- igniting plasma directly in said mixed gas at said second pressure by energizing said plasma generator;
- and
- increasing, after ignition of said plasma, a pressure inside said processing vessel to said first pressure from said second pressure while maintaining said plasma,
- wherein said step of increasing said pressure includes a phase in which a flow rate of said mixed gas is increased together with said pressure,
- wherein said plasma generator is a toroidal plasma generator, said toroidal plasma generator comprising a gas passage, said gas passage having a gas entrance and a gas outlet, forming a circuitous path, and having a coil wound around a part of said gas passage such that said coil winds around said gas passage at least twice, and
- wherein said energizing is conducted by feeding a current to said coil.
A substrate processing method for etching a surface of a substrate to be processed by plasma-excited radicals under a first pressure, comprising the steps of:
- introducing a mixed gas of a diluting gas and an etching gas into a plasma generator under a second pressure lower than said first pressure;
- igniting plasma directly in said mixed gas at said second pressure by energizing said plasma generator;
- and
- increasing, after ignition of said plasma, said pressure inside said processing vessel to said first pressure from said second pressure while maintaining said plasma,
- wherein said step of increasing said pressure includes a phase in which a flow rate of said mixed gas is increased together with said pressure,
- wherein said plasma generator is a toroidal plasma generator, said toroidal plasma generator comprising a gas passage, said gas passage having a gas entrance and a gas outlet, forming a circuitous path, and having a coil wound around a part of said gas passage such that said coil winds around said gas passage at least twice, and
- wherein said energizing is conducted by feeding a current to said coil.
Dependencies are inferred from the claim text.