Wet-chemical treatment method, treatment method of semiconductor substrate, and manufacturing method of semiconductor device

Abstract

In a wet-chemical treatment of a semiconductor substrate with a chemical treatment fluid containing ammonia and hydrogen peroxide, an experiment is carried out in a system where the concentrations of chemical species are known, to experimentally previously determine a relation between an etching rate of an SiO,film with a mixture of ammonia and hydrogen peroxide and the concentrations of the dissolved chemical species (calculated by a chemical equilibrium analysis) or the temperature of the chemical treatment fluid, and the determined relation is then expressed. The concentrations of the chemical species are calculated by the chemical equilibrium analysis on the basis of values measured by a chemical treatment fluid composition monitor at a suitable interval and values measured by a fluid temperature sensor, and in accordance with the expressed relation, the etching rate of the SiO,film with the chemical treatment fluid is calculated at the suitable interval. This result is fed back to a replenish mechanism of a wet-chemical treatment apparatus to regulate the amounts of the chemicals, thereby controlling the concentrations of the chemical treatment fluid. In consequence, there can be provided a wet-chemical treatment method which can stably treat the semiconductor.