Methods and systems for plasma etching process
AssigneeTokyo Electron Limited
InventorsDu Zhang, Yu-Hao Tsai
Life of this patent
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Abstract
A method is provided for processing a substrate. The method includes loading a substrate in a process chamber, the substrate including a mask layer disposed over a layer to-be-etched. A patterned mask layer is formed from the mask layer through a lithography process. An etch gas including chlorine and fluorine, or bromine and fluorine and a passivation gas including oxygen or fluorocarbon are flowed into the process chamber. The etch gas is supplied in periodic pulses while the passivation gas is supplied continuously. A radio frequency (RF) source power is applied to generate a plasma from the etch gas and the passivation gas. The layer to-be-etched is etched through the patterned mask layer to form a feature in the layer to-be-etched.
Claims20
A method for processing a substrate, the method comprising:
- loading a substrate in a process chamber, the substrate comprising a mask layer disposed over a layer to-be-etched;
- forming a patterned mask layer from the mask layer through a lithography process;
- flowing an etch gas comprising chlorine and fluorine, or bromine and fluorine and a passivation gas comprising oxygen or fluorocarbon into the process chamber, wherein the etch gas is supplied in periodic pulses while the passivation gas is supplied continuously;
- applying a radio frequency (RF) source power to generate a plasma from the etch gas and the passivation gas;
- and
- etching the layer to-be-etched through the patterned mask layer to form a feature in the layer to-be-etched, the etching selectively etching bottom surfaces of the feature and forming passivation layer over sidewalls of the feature to protect the sidewalls from etching.
A method for processing a substrate, the method comprising:
- providing a substrate in a process chamber, the substrate comprising a patterned mask layer disposed over a layer to-be-etched;
- performing a cyclic etch processing on the substrate, the cyclic etch processing comprising:
- flowing an etch gas comprising chlorine and fluorine, or bromine and fluorine into the process chamber,
- applying a radio frequency (RF) source power to generate a first plasma from the etch gas, wherein the first plasma etches the layer to-be-etched through the patterned mask layer to form a feature in the layer to-be-etched,
- after stopping the flow of the etch gas, flowing a passivation gas comprising oxygen or fluorocarbon into the process chamber, and
- applying the RF source power to generate a second plasma from the passivation gas, wherein the second plasma forms a passivation layer over sidewalls of the feature;
- and
- continuing the cyclic etch processing until a predetermined aspect ratio of the feature is achieved.
A method for processing a substrate, the method comprising:
- loading a substrate in a process chamber, the substrate comprising a layer to-be-etched disposed over an etch stop layer;
- flowing a plurality of gases in the process chamber, the plurality of gases comprising an etch gas comprising chlorine and fluorine, or bromine and fluorine and a passivation gas comprising oxygen or fluorocarbon;
- applying cyclic power pulses to power electrodes in the process chamber to generate a plasma from the plurality of gases, wherein one cycle of the cyclic power pulses comprising:
- a first plurality of pulses to a source power (SP) electrode, and
- a second plurality of pulses to a bias power (BP) electrode, wherein the second plurality of pulses are synchronized with the first plurality of pulses;
- and
- etching the layer to-be-etched using the plasma to form a feature in the layer to-be-etched until a top surface of the etch stop layer is exposed, the etching selectively etching bottom surfaces of the feature and forming passivation layer over sidewalls of the feature to protect the sidewalls from etching.
Dependencies are inferred from the claim text.