Method of inspecting semiconductor substrate and method of manufacturing semiconductor device

A method of inspecting a semiconductor substrate, the method comprising:

• measuring light intensity of light reflected on the semiconductor substrate while the semiconductor substrate rotates;
• analyzing a frequency distribution of the measured light intensity;
• and
• determining a state of the semiconductor substrate based on the frequency distribution of the light intensity,
• wherein the analyzing of the frequency distribution of the light intensity comprises normalizing the frequency distribution of the light intensity, and
• wherein the normalizing of the frequency distribution of the light intensity comprises extracting from the measured light intensity a direct-current (DC) component corresponding to a frequency of 0 Hz, a first frequency component corresponding to a first frequency, and a second frequency component corresponding to a second frequency, which is twice the first frequency, and normalizing the first frequency component and the second frequency component by using the DC component.

A method of manufacturing a semiconductor device, the method comprising:

• setting a processing environment of a semiconductor substrate;
• processing the semiconductor substrate according to the processing environment;
• inspecting the semiconductor substrate in real-time to determine a state of the semiconductor substrate;
• and
• determining whether the processing of the semiconductor substrate is to be continued based on the determined state of the semiconductor substrate,
• wherein the inspecting the semiconductor substrate in real-time comprises:
• measuring light intensity of light reflected on the semiconductor substrate while the semiconductor substrate rotates;
• calculating a frequency distribution of the measured light intensity;
• and
• determining the state of the semiconductor substrate by using the frequency distribution of the light intensity,
• wherein the calculating of the frequency distribution of the measured light intensity comprises extracting a plurality of frequency components corresponding respectively to a plurality of frequencies from the measured light intensity, and
• wherein the calculating of the frequency distribution of the measured light intensity comprises extracting from the measured light intensity a direct-current (DC) component corresponding to a frequency of 0 Hz, a first frequency component corresponding to a first frequency, and a second frequency component corresponding to a second frequency, which is twice the first frequency.