co 2 rinse then removes the solvent mixture from the vessel a mixture consisting of pyridine and hf is then added the mixture composition by weight is 99 5 0 5 and the total concentration of adjunct added is 8 of the overall weight the second solvent mixture contacts the substrate for 10 seconds and is then followed by a pure supercritical co 2 rinse the system is vented and the substrate removed polymeric photoresist and resist residue is removed from a via post reactive ion etch rie of a test structure using the following process steps the substrate is placed in the pressure vessel morpholine and methanol in supercritical co 2 is added to the vessel at 3 000 psi at 75 u00b0 c the mixture composition by weight is 20 80 and the total concentration of the adjunct added is 2 the fluid mixture circulates through the vessel for 2 minutes a second cleaning solution consisting of pyridine hf and a high purity surfactant displaces the first cleaning solution the mixture composition by weight is 93 6 1 and the total concentration of the adjunct added is 1 of the overall weight the second mixture contacts the substrate for 1 minute finally a pure supercritical co 2 rinse is completed by the addition of pure co 2 to the vessel the system is depressurized and the substrate removed polymeric photoresist and etch residue is removed from a trench post rie of a test structure using the following process steps the substrate is loaded into the pressure vessel and supercritical co 2 is added to the vessel to 2 400 psi at 60 u00b0 c.