ANISOTROPIC THERMAL ETCHING OF SiO2
AssigneeLam Research Corporation
InventorsEric A. HUDSON, Prabhat KUMAR
Life of this patent
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Abstract
A method for etching features in a stack is provided. A plurality of cycles is provided. A thermal etch step for etching the features in the stack is provided in the cycle, where the stack comprises at least one silicon oxide layer, and the thermal etch step, comprises providing a thermal etch gas in vapor phase comprising a halogen containing vapor or gas and a vapor catalyst and providing thermal energy to drive a reaction that etches the features in the stack. A passivation step for depositing a passivation layer on sidewalls of the features is provided in the cycle.
Claims23
A method for etching features in a stack, comprising providing a plurality of cycles, wherein each cycle comprises:
- a) providing a thermal etch step for etching the features in the stack, wherein the stack comprises at least one silicon oxide layer, the thermal etch step comprising:
- providing a thermal etch gas in vapor phase, comprising:
- a halogen containing vapor or gas;
- and
- a vapor catalyst;
- and
- providing thermal energy to drive a reaction that etches the features in the stack;
- and
- b) providing a passivation step for depositing a passivation layer on sidewalls of the features.
A method for etching features in a stack, comprising providing a plurality of cycles, wherein each cycle comprises:
- a) providing a plasma etch;
- and
- b) providing a thermal etch for etching features in the stack, wherein the stack comprises at least bilayers, wherein at least one layer of the at least bilayers is a silicon oxide layer, comprising:
- providing a thermal etch gas in vapor phase, comprising:
- a halogen containing vapor or gas;
- and
- a vapor catalyst;
- and
- providing thermal energy to drive a reaction that etches features in the stack.
An apparatus for etching a substrate, the apparatus comprising:
- a. a reaction chamber configured to provide a pressure between about 0.2-10 Torr in the reaction chamber;
- b. a substrate support configured to support the substrate in the reaction chamber;
- c. at least one inlet for introducing a gas mixture to the reaction chamber;
- d. a halogen vapor or gas source for providing a halogen vapor or gas to the at least one inlet;
- e. a vapor catalyst source for providing a vapor catalyst to the at least one inlet;
- f. at least one of a passivation gas source and an etch plasma gas source connected to the at least one inlet;
- g. a heater for providing thermal energy to the substrate;
- h. an outlet for removing vapor from the reaction chamber;
- and
- f. a controller configured to provide a cyclical process, wherein the cyclical process, comprising:
- a thermal etch step;
- and
- at least one of a passivation step and a plasma etch.
Dependencies are inferred from the claim text.