Patent ID: 8685169

Claim:
A substrate processing apparatus comprising: a processing bath to process a substrate by immersing the substrate in SPM liquid (sulfuric acid and hydrogen peroxide mixture); a circulation path to circulate the SPM liquid in the processing bath; a heating unit provided in the circulation path to heat the SPM liquid; a sulfuric acid supply unit to supplement sulfuric acid to the SPM liquid; a hydrogen peroxide supply unit including an opening/closing valve provided at a downstream side of the heating unit in the circulation path in front of an outlet of the circulation path configured to selectively supplement hydrogen peroxide to the SPM liquid while the SPM liquid is circulating in the circulation path such that the SPM liquid is supplied to the processing bath in a state where the hydrogen peroxide supplied from the hydrogen peroxide supply unit and Caro's acid generated by a reaction between the hydrogen peroxide and the sulfuric acid are prevented from being directly heated by the heating unit, and decomposition of the hydrogen peroxide and Caro's acid is restrained; a temperature detection unit to detect a temperature of the SPM liquid in the processing bath; and a control unit that is programmed to control an overall operation of the substrate processing apparatus, the programming comprising: adjusting an output of the heating unit based on the temperature detected by the temperature detection unit such that the temperature of the SPM liquid in the processing bath is maintained in a predetermined range of 135Â° C. to 170Â° C., supplementing the SPM liquid by the hydrogen peroxide through the hydrogen peroxide supply unit such that the SPM liquid supplemented by the hydrogen peroxide is supplied to the processing bath after the substrate is immersed in the SPM liquid in the processing bath, and supplementing the sulfuric acid from the sulfuric acid supply unit to compensate for the SPM liquid as the SPM liquid is evaporated by heating.