An etching method includes: providing a substrate having a film and a patterned mask on the film; forming a silicon-containing layer including silicon, carbon, and nitrogen on the substrate using a precursor gas containing silicon; and performing a plasma etching on the film. The substrate is placed under a depressurized environment for a time period from a start time point of the step of forming the silicon-containing layer on the substrate to an end time point of the step of performing the plasma etching on the film.

A semiconductor device manufacturing method includes: forming an organic film composed of a polymer having a urea bond in a recess by supplying amine and isocyanate to a surface of a substrate having the recess; performing a predetermined process on the substrate on which the organic film is formed in the recess; and removing the organic film in the recess by heating the substrate that has been subjected to the predetermined process to depolymerize the organic film. The amine and the isocyanate have a terminal bifunctional linear chain structure having two functional groups at both ends of a linear chain. At least one of the amine or the isocyanate has side chains connected to the linear chain contained in the linear chain structure.

A protective film forming agent that, in dicing of a semiconductor wafer, is used to form a protective film on the surface of the semiconductor wafer, can form a protective film that has excellent laser processability, and has excellent solubility of a light-absorbing agent; and a method for producing a semiconductor chip using the protective film forming agent. The protective film forming agent includes a water-soluble resin, a light-absorbing agent, a basic compound, and a solvent. The basic compound is an alkylamine, an alkanolamine, an imidazole compound, ammonia, or an alkali metal hydroxide. The light-absorbing agent content of the protective film forming agent is 0.1-10 mass % (inclusive).

Embodiments of the disclosure relate to methods of selectively depositing polysilicon after forming a flowable polymer film to protect a substrate surface within a feature. A first silicon (Si) layer is deposited by physical vapor deposition (PVD). The flowable polymer film is formed on the first silicon (Si) layer on the bottom. A portion of the first silicon (Si) layer is selectively removed from the top surface and the at least one sidewall. The flowable polymer film is removed. In some embodiments, a second silicon (Si) layer is selectively deposited on the first silicon (Si) layer to fill the feature. In some embodiments, the remaining portion of the first silicon (Si) layer on the bottom is oxidized to form a first silicon oxide (SiOx) layer on the bottom, and a silicon (Si) layer or a second silicon oxide (SiOx) layer is deposited on the first silicon oxide (SiOx) layer.