Method for detecting end point in plasma etching by impedance change
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsJen-Yuan Yang, Tsai-Yi Chen, Wen-Bin Lin
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Abstract
A method for detecting end-point in a plasma etching process by monitoring plasma impedance changes on a time scale is disclosed. In the method, a plasma etching process is first conducted in a process chamber, while changes in a parameter of plasma impedance in the chamber occurring during the etching process is recorded in a curve on a time scale. An end-point of the plasma etching process is then defined for the etching of a specific material layer at a point where the direction of a slope of the curve changes.
Claims18
A method for detecting end-point in plasma etching by impedance change comprising the steps of:
- conducting a plasma etching process in a process chamber;
- recording in a curve changes in a parameter of plasma impedance in said chamber occurring during said etching process on a time scale;
- and
- defining an end-point of the plasma etching process for a specific material layer as a point where the direction of a slope of the curve changes.
A method for detecting end-point in plasma etching by RF match capacitance change comprising the steps of:
- conducting a plasma etching process in a process chamber;
- recording in a curve changes in a parameter of RF match capacitance in said chamber during said etching process on a time scale;
- and
- defining an end-point of the plasma etching process for a specific material layer as a point where a direction of a slope of the curve changes.
A method for detecting end-point in plasma etching by changes in RF coil tuning counts comprising the steps of:
- conducting a plasma etching process in a process chamber;
- recording in a curve changes in a parameter of RF coil tuning counts in said chamber during said etching process on a time scale;
- and
- defining an end-point of the plasma etching process for a specific material layer as a point where the direction of a slope of the curve changes.
Dependencies are inferred from the claim text.