Substrate treating apparatus and method of treating substrate

A method of treating a substrate, the method comprising:

• supplying a chemical solution to a substrate in a bath to perform a process on the substrate, the chemical solution having a first temperature including a silicon compound and a phosphoric acid aqueous solution;
• circulating the chemical solution;
• sampling at least a portion of the circulated chemical solution;
• measuring a water concentration and a silicon concentration of the sampled chemical solution having a second temperature lower than the first temperature;
• and
• calculating a revised silicon concentration of the chemical solution in the bath at the first temperature based on the water concentration and the silicon concentration of the sampled chemical solution at the second temperature,
• wherein measuring the silicon concentration includes preventing a measurement error of the silicon concentration and preventing a silicon deposit, which occur by the silicon concentration increasing during the process.

A method of treating a substrate, the method comprising:

• supplying a chemical solution to a substrate in a bath to perform a process on the substrate, the chemical solution having a first temperature and including a silicon compound and a phosphoric acid aqueous solution;
• circulating the chemical solution;
• sampling at least a portion of the circulated chemical solution;
• measuring a water concentration and a silicon concentration of the sampled chemical solution having a second temperature lower than the first temperature;
• and
• calculating a revised silicon concentration of the chemical solution in the bath at the first temperature based on the water concentration and the silicon concentration of the sampled chemical solution at the second temperature,
• wherein:
• performing the process on the substrate increases the silicon concentration of the chemical solution, and
• measuring the silicon concentration includes cleaning a silicon concentration measurer that measures the silicon concentration.