An etchant composition may include: a peroxosulfate; a cyclic amine compound; a first amphoteric compound including a carboxyl group; and a second amphoteric compound including a sulfone group, wherein the second amphoteric compound may be different from the first amphoteric compound.

An etchant composition may include: a peroxosulfate; a cyclic amine compound; a first amphoteric compound including a carboxyl group; and a second amphoteric compound including a sulfone group, wherein the second amphoteric compound may be different from the first amphoteric compound.

The present invention relates to a method for etching at least one surface of a plastic substrate, the method comprising steps (A) to (C), wherein step (B) comprises a contacting with a pre-treatment composition comprising one or more than one fluorine-free surface-active compound, and step (C) comprises a contacting with an etching composition comprising one or more than one manganese species, wherein after step (B) and prior to step (C) no rinsing is applied, and the etching composition is substantially free of, preferably does not comprise, fluorine-containing surface-active compounds.

The present invention relates to a method for etching at least one surface of a plastic substrate, the method comprising steps (A) to (C), wherein step (B) comprises a contacting with a pre-treatment composition comprising one or more than one fluorine-free surface-active compound, and step (C) comprises a contacting with an etching composition comprising one or more than one manganese species, wherein after step (B) and prior to step (C) no rinsing is applied, and the etching composition is substantially free of, preferably does not comprise, fluorine-containing surface-active compounds.

An electroless etching process. The process produces nanostructured semiconductors in which an oxidant (Ox.sub.1) is deposited as a metal on a semiconductor surface and used as a catalytic agent to facilitate reaction between a semiconductor and a second oxidant (Ox.sub.2). Ox.sub.2 is used to initiate etching by injecting holes into the semiconductor valence band as facilitated by the catalytic action of the deposited metal. The extent of reaction is controlled by the amount of Ox.sub.2 added; the reaction rate is controlled by the injection rate of Ox.sub.2. The process produces high specific surface area and/or hierarchically structured porous Si with higher and controllable yield. In addition, the ability is demonstrated to vary the pore size distribution of mesoporous silicon including producing hierarchically structured mesoporous silicon with more than one peak in the pore size distribution. In principle, the process applies to any semiconductor onto which metal can be deposited galvanically.

An electroless etching process. The process produces nanostructured semiconductors in which an oxidant (Ox.sub.1) is deposited as a metal on a semiconductor surface and used as a catalytic agent to facilitate reaction between a semiconductor and a second oxidant (Ox.sub.2). Ox.sub.2 is used to initiate etching by injecting holes into the semiconductor valence band as facilitated by the catalytic action of the deposited metal. The extent of reaction is controlled by the amount of Ox.sub.2 added; the reaction rate is controlled by the injection rate of Ox.sub.2. The process produces high specific surface area and/or hierarchically structured porous Si with higher and controllable yield. In addition, the ability is demonstrated to vary the pore size distribution of mesoporous silicon including producing hierarchically structured mesoporous silicon with more than one peak in the pore size distribution. In principle, the process applies to any semiconductor onto which metal can be deposited galvanically.

The present invention is in the field of chemical cleaning and surface treatments for a stainless steel substrate. In particular, the present invention provides a method, kit and use of specific solutions for removing and preferably preventing the formation of rouging (e.g. class I, II and/or III) on a stainless steel substrate, which may be used as processing station or production unit.

The present invention is in the field of chemical cleaning and surface treatments for a stainless steel substrate. In particular, the present invention provides a method, kit and use of specific solutions for removing and preferably preventing the formation of rouging (e.g. class I, II and/or III) on a stainless steel substrate, which may be used as processing station or production unit.

The polishing liquid according to the embodiment comprises abrasive grains, an additive and water, wherein the abrasive grains satisfy either or both of the following conditions (a) and (b).

(a) Producing absorbance of at least 1.50 for light with a wavelength of 400 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass %, and also producing light transmittance of at least 50%/cm for light with a wavelength of 500 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass %.

(b) Producing absorbance of at least 1.000 for light with a wavelength of 290 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 0.0065 mass %, and also producing light transmittance of at least 50%/cm for light with a wavelength of 500 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass %.

The polishing liquid according to the embodiment comprises abrasive grains, an additive and water, wherein the abrasive grains satisfy either or both of the following conditions (a) and (b).

(a) Producing absorbance of at least 1.50 for light with a wavelength of 400 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass %, and also producing light transmittance of at least 50%/cm for light with a wavelength of 500 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass %.

(b) Producing absorbance of at least 1.000 for light with a wavelength of 290 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 0.0065 mass %, and also producing light transmittance of at least 50%/cm for light with a wavelength of 500 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass %.