Eaton Corporation

Axcelis Technologies, Inc.

Qingyan Han

Palani Sakthivel

Ricky Ruffin

Ivan Berry

Mahmoud Dahimene

Andre G Cardoso

A method for stripping photoresist and/or removing post etch residues from an exposed low k dielectric layer of a semiconductor wafer in the presence or absence of copper. The method comprises creating an oxygen free plasma by subjecting an oxygen free gas to an energy source to generate the plasma having electrically neutral and charged particles. The charged particles are then selectively removed from the plasma. The electrically neutral particles react with the photoresist and/or post etch residues to form volatile gases which are then removed from the wafer by a gas stream. The oxygen free, plasma gas composition for stripping photoresist and/or post etch residues comprises a hydrogen bearing gas and a fluorine bearing wherein the fluorine bearing gas is less than about 10 percent by volume of the total gas composition.

Oxygen free plasma stripping process

A method for determining an endpoint for an oxygen free plasma stripping process for use in semiconductor wafer processing. The method comprises exciting a gas composition containing a nitrogen gas and a reactive gas to form the oxygen free plasma. The oxygen free plasma reacts with a substrate having a photoresist and/or residues thereon to produce emitted light signals corresponding to an oxygen free reaction product. The endpoint is determined by optically measuring a primary emission signal of the oxygen free reaction product at a wavelength of about 387 nm. The endpoint is determined when the plasma no longer reacts with the photoresist and/or residues on the substrate to produce the emitted light at about 387 nm, an indication that the photoresist and/or residues have been removed from the wafer. Secondary emission signals of the oxygen free reaction product at about 358 nm and 431 nm can also be monitored for determining the endpoint.

Method for detecting an endpoint for an oxygen free plasma process

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Columbia, MD, United States of America

Qingyan Han