Plasma passivation

A method for forming an aluminum trace on a substrate, the method comprising:

• patterning the aluminum trace with a photoresist mask,
• etching the aluminum trace, and thereby forming a polymer layer on a top surface and sidewalls of the photoresist mask and on sidewalls of the aluminum trace, where the polymer layer contains entrained chlorine gas,
• heating the substrate on a chuck in a reaction chamber,
• generating a remote plasma from ammonia gas and oxygen gas in a ratio of between one of about 1:100 to 1:50, and about 10:1, contacting the substrate with the ammonia and oxygen plasma, thereby withdrawing a substantial portion of the entrained chlorine gas from the polymer layer,
• applying a radio frequency potential to the chuck on which the substrate resides, thereby creating a reactive ion etchant from the ammonia and oxygen plasma in the reaction chamber and removing the polymer layer from the top surface of the photoresist mask, and thereby exposing the photoresist mask, and
• removing the exposed photoresist mask in an ashing process.

A method for forming an aluminum trace on a substrate, the method comprising:

• patterning the aluminum trace with a photoresist mask,
• etching the aluminum trace, and thereby forming a polymer layer on a top surface and sidewalls of the photoresist mask and on sidewalls of the aluminum trace, where the polymer layer contains entrained chlorine gas,
• heating the substrate on a chuck in a reaction chamber,
• generating a remote plasma from ammonia gas and oxygen gas using a microwave generator,
• adjusting a ratio of the ammonia gas and the oxygen gas in the remote plasma to minimize oxidation of the sidewalls of the aluminum trace,
• contacting the substrate with the ammonia and oxygen plasma, thereby withdrawing a substantial portion of the entrained chlorine gas from the polymer layer,
• applying a radio frequency potential to the chuck on which the substrate resides, thereby creating a reactive ion etchant from the ammonia and oxygen plasma in the reaction chamber and removing the polymer layer from the top surface of the photoresist mask, and thereby exposing the photoresist mask, and
• removing the exposed photoresist mask in an ashing process.