Strippers for removal of organic films and deposits, such as the polymeric etch resists employed in the manufacture of semiconductors from inorganic surfaces commonly encountered in the electrical and electronic industries, are composed of solutions of chromium trioxide in mixtures of strong nitric and sulfuric acids containing about 2 percent to about 20 percent water.
This application is a continuation-in-part of application Ser. No. 75660 filed Sept. 25, 1970 now U.S. Pat. No. 3,676,219 which is in turn a continuation-in-part of application Ser. No. 866,036 filed Oct. 13, 1969 now abandoned.
A method for preparing and using a certain conditioning and passivation composition on metals and the composition of matter used for such conditioning and passivation, which method involves immersing the metal in a bath consisting of specified quantities of nitric acid, sulfuric acid and chromium trioxide in water. The treatment produces a clean and bright surface on the metal that is resistant to corrosion, without attacking the substrate metal. The passivation composition of the present invention can be used as a final passivation and corrosion removal treatment for stainless steel and as a corrosion removal and passivation treatment for other non ferrous metals.
A stripping solution comprising between 80 and 98% H.sub.2 SO.sub.4, between 0.5 and 4% HClO.sub.4, between 0.5 and 4% CrO.sub.3 and H.sub.2 O. The principal application of the solution is to remove polymerized photoresist layers formed during the manufacture of semiconductor devices.
The present invention provides a method of removing a photoresist film, which exhibits the high ability to remove photoresist and excellent safety and handling properties such as workability, In the removing method, the photoresist film is removed by chemical decomposition in an inorganic aqueous solution under ultraviolet-light irradiation. The inorganic aqueous solution is an aqueous solution of peroxomonosulfate or an aqueous solution containing 4.5 to 36 wt % of sulfuric acid and 0.05 to 0.8 wt % of hydrogen peroxide.
Disclosed is an interdispersed three-phase ferrite composite which comprises from about 0.1 mole to about 1.0 mole of a spinel phase having the general formula MFe.sub.2 O.sub.4 where M is at least one element that forms a spinel ferrite and is selected from the group consisting of cobalt, manganese, iron and mixtures thereof, to about 2.5 moles of a magnetoplumbite phase having the general formula PO.6Fe.sub.2 O.sub.3 where P is selected from the group consisting of strontium, barium, calcium, lead and mixtures thereof and, as a third phase, from about 0.02 to about 2.0 percent by weight, based on the combined weight of the spinel phase and the magnetoplumbite phase, of TiO.sub.2 or SiO.sub.2. Also disclosed are carrier particles formed from magnetized particles of the composite which optionally can be polymerically coated, an electrostatic charged toner particles mixed with oppositely charged carrier particles formed from magnetized, and optionally polymerically coated, particles of the composite, and a method of developing an electrostatic image by contacting the image with a two-component dry developer composition described above.
Process for rinsing a metallized substrate subject to metal microcorrosion using an acidic aqueous rinsing solution wherein the rinsing solution comprises at least one strong inorganic acid in an amount enough to reduce the alkalinity of the rinse solution to a level low enough to reduce microcorrosion of the said metal layer while rinsing.
