Patent ID: 9075318
Filing Date: 2015-07-07
Classification: G03F,H01L

Abstract:
1. A method for stripping a resist on a plurality of substrates with a treatment liquid in a resist removal system comprising a processing chamber and recirculation system, the resist removal system having strip process parameters, the treatment liquid comprising a mixture of sulfuric acid and hydrogen peroxide, and one or more reactive products including persulfuric acid, the method comprising: (a) selecting target stripping objectives for stripping the resist on the plurality of substrates, wherein each of the plurality of substrates includes one or more silicon-containing materials, and wherein the target stripping objectives include a rate of stripping the resist and a selectivity for stripping the resist versus etching of the silicon-containing materials; (b) determining target operating ranges of the strip process parameters to achieve the target stripping objectives, the strip process parameters including a target dispense temperature and a target dispense composition for dispensing the treatment liquid into the processing chamber for exposing to the plurality of substrates, wherein the target dispense composition includes a target stripping ratio of sulfuric acid to hydrogen peroxide and a target persulfuric acid concentration; (c) after initially establishing the treatment liquid in the processing chamber, continuously recirculating the treatment liquid from the processing chamber through a recycle line in the recirculation system and dispensing the treatment liquid back into the processing chamber at the target dispense temperature and the target dispense composition; (e) during the recirculating, diverting a portion of the treatment liquid in the recirculation system from the recycle line to a bypass line along which is a reaction zone for generating persulfuric acid followed by a temperature adjustment zone; (f) during the recirculating, monitoring the composition and temperature of the treatment liquid in the recirculation system and adjusting the monitored composition and/or the temperature to achieve the target dispense temperature and the target dispense composition before dispensing the treatment liquid back into the processing chamber, wherein the adjusting includes injecting sulfuric acid, or hydrogen peroxide, or both into the treatment liquid in the recirculation system to: