Dual mode plasma etching system and method of plasma endpoint detection
First Claim
1. A method of etching a designated layer of a specified material on a substrate, the steps of the method comprising:
- depositing a thin sacrificial film of a second material distinct from said specified material on said substrate, wherein said thin sacrificial film functions as a plasma etching process marker;
forming said designated layer of said specified material on top of said thin film, wherein said thin sacrificial film is much thinner than said designed layer of said specified material;
etching said designated layer in a plasma etching chamber while applying a first level of power to said plasma etching chamber;
detecting a first endpoint at which time said plasma etching chamber begins etching said thin film of second material; and
subsequent to said first endpoint detection, ceasing application of said first level of power to said plasma chamber and removing portions of said thin film remaining on said substrate subsequent to said first endpoint detection by using a process less damaging to said substrate than etching in said plasma etching chamber while applying said first level of power to said plasma etching chamber.
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Accused Products
Abstract
A dual mode plasma etching system and method for plasma etching endpoint detection etches a designated layer of a specified material on a substrate without exposing the substrate surface to a high-energy etching plasma. The substrate is prepared for etching by depositing a thin film of a second material distinct from the specified material on the substrate surface. The designated layer of specified material is formed on top of the thin film. Etching of the designated layer in a plasma etching chamber then proceeds while a preferably high level of power is applied to the plasma etching chamber. The dual mode etching system generates an endpoint signal resulting in termination of the high-power etch when the plasma etching chamber begins etching the thin film of second material. Portions of the thin film remaining on the substrate are then removed using a process less damaging to the substrate than etching at high power.
55 Citations
7 Claims
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1. A method of etching a designated layer of a specified material on a substrate, the steps of the method comprising:
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depositing a thin sacrificial film of a second material distinct from said specified material on said substrate, wherein said thin sacrificial film functions as a plasma etching process marker; forming said designated layer of said specified material on top of said thin film, wherein said thin sacrificial film is much thinner than said designed layer of said specified material; etching said designated layer in a plasma etching chamber while applying a first level of power to said plasma etching chamber; detecting a first endpoint at which time said plasma etching chamber begins etching said thin film of second material; and subsequent to said first endpoint detection, ceasing application of said first level of power to said plasma chamber and removing portions of said thin film remaining on said substrate subsequent to said first endpoint detection by using a process less damaging to said substrate than etching in said plasma etching chamber while applying said first level of power to said plasma etching chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification