Method for etching metal lines with enhanced profile control
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsL. C. Chao, M. H. Huang, C. H. Yu
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Abstract
The present invention discloses a method for enhancing profile control in a metal line etching process in which a main etching step and an over etching step are used by incorporating a charge neutralization step for the photoresist layer by an inert gas plasma such that plasma ions aimed at the horizontal surface on the semiconductor substrate is not distorted to bombard the sidewalls on the metal lines. The anisotropic etching of the metal lines is improved to provide metal lines on a device that has enhanced profile control and without the void or cavity defect.
Claims20
A method for etching metal lines with enhanced profile control comprising the steps of:
- providing a semiconductor device having a metal layer deposited on top,
- depositing and patterning a photoresist layer on top of said metal layer,
- plasma etching lines in said metal layer and stopping at a metal/TiN interface in a first etching step,
- neutralizing charges in said photoresist layer by an inert gas plasma, and
- plasma etching said lines through said TiN layer in a second etching step.
A method for enhancing profile control in a metal line etching process comprising the steps of:
- providing a semiconductor device having a metal layer deposited on top,
- depositing and patterning a photoresist layer on top of said metal layer, said photoresist layer produces a passivation material in a gas plasma,
- anisotropically etching lines in said metal layer in a first etching step stopped by an end-point mode,
- neutralizing electrostatic charges built-up in said photoresist layer by an inert gas plasma, and
- anisotropically etching said lines in a second etching step stopped by a time mode.
Dependencies are inferred from the claim text.