Substrate processing device

Abstract

Disclosed is a substrate processing device that can directly detect the concentration of a processing liquid, and thus is able to perform independent concentration control mostly without being affected by the temperature of the processing liquid, and is able to accurately perform chemical processing of a substrate. The substrate processing device, which processes by immersing the substrate in the processing liquid comprising a mixture of a chemical and a diluting liquid, is provided with: a processing tank (1) that retains the processing liquid; heating means (2, 3) that heat the processing liquid; a temperature detection means (4) that detects the temperature of the processing liquid; a temperature control means (5) that operates the aforementioned heating means (2, 3) in a manner so that the detected temperature approaches a set temperature; a replenishing means (6) that replenishes the diluting liquid in the processing liquid; a concentration detection means (7) that detects the concentration of the processing liquid by measuring the light absorption characteristics of the processing liquid; and a concentration control means (8) that operates the aforementioned replenishing means (6) in a manner so that the detected concentration approaches a set concentration.

Description

technical field [0001] The present invention relates to a substrate processing apparatus for processing substrates such as semiconductor wafers, glass substrates for liquid crystal display devices, and glass substrates for photomasks (hereinafter, simply referred to as "substrates") using a processing liquid. A technique for controlling the concentration of the treatment liquid when the treatment is performed in the treatment liquid heated to a high temperature is useful. Background technique [0002] Conventionally, as such a substrate processing apparatus, one using, for example, high-temperature phosphoric acid (H 3 PO 4 ) solution to etch the silicon nitride film (SiN) on the surface of the substrate. [0003] For example, in a semiconductor wafer process, when a silicon nitride film is etched using a phosphoric acid solution, a silicon dioxide film (SiO 2 ). In this case, it is generally required that only the silicon nitride film is etched, and the silicon dioxide ...

AI Technical Summary

Problems solved by technology

However, in actual operation, there is the following problem: when the diluent is added to the treatment liquid in order to control the concentration of the treatment liquid, since the temperature of the treatment liquid also changes, the temperature of the treatment liquid will not return to the set temperature until the temperature of the treatment liquid returns to the set temperature. , cannot measure the exact concentration

As a result, the diluent evaporates, and the concentration of the processing liquid increases, causing the etching rate of the silicon nitride film to become unstable.

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