Defect inspection device and defect inspection method

A defect inspection method comprising:

• emitting, by a light source, light onto a substrate disposed on a stage via an objective lens;
• measuring, by a light quantity measurement sensor, an amount of the light reflected from a first region of a main surface of the substrate;
• receiving, by a controller, information about the amount of the light measured by the light quantity measurement sensor;
• calculating, by the controller, a difference value between the amount of the light that is measured by the light quantity measurement sensor and a reference amount of light that is preset and then transmitting the difference value to a light quantity regulator;
• correcting, by the light quantity regulator, an amount of light emitted to the first region based on the difference value;
• after the correcting of the amount of the light in the first region based on the difference value by the light quantity regulator, measuring, by the light quantity measurement sensor, an amount of light that is reflected from an nth region adjacent to an n−1th region of the main surface of the substrate;
• receiving, by the controller, information about the amount of the light measured by the light quantity measurement sensor;
• calculating, by the controller, a difference value between the amount of the light in the nth region that is measured by the light quantity measurement sensor and the reference amount of light that is preset and then transmitting the difference value to the light quantity regulator;
• and
• correcting, by the light quantity regulator, an amount of light emitted to the nth region based on the difference value,
• where n is an integer of 2 or more.

A defect inspection device comprising:

• a stage configured on which to mount a substrate;
• an objective lens disposed above the stage to project light onto the substrate;
• a light source configured to provide light onto a main surface of the substrate via the objective lens;
• a light quantity measurement sensor disposed above the stage and configured to measure an amount of the light that is reflected from a first region of the main surface of the substrate;
• a light quantity regulator located between the light source and the objective lens and configured to regulate an amount of the light that is emitted from the light source onto the main surface of the substrate;
• a controller configured to control the light quantity regulator so that the light quantity regulator regulates the amount of the light provided to the first region on a basis of information about the amount of the light reflected from the first region measured by the light quantity measurement sensor;
• and
• an image sensor configured to capture an image of the light reflected from the main surface of the substrate,
• wherein the light quantity measurement sensor is disposed between the stage and the image sensor,
• wherein the controller is configured to control the light quantity regulator so that the amount of the light emitted to the first region decreases when the amount of the light in the first region measured by the light quantity measurement sensor is greater than a reference amount of light that is preset and the amount of the light emitted to the first region increases when the amount of the light in first region measured by the light quantity measurement sensor is less than the reference amount of light that is preset,
• wherein the light quantity measurement sensor is configured to measure an amount of light reflected from an nth region adjacent to an n−1th region of the main surface of the substrate after the light quantity regulator regulates the amount of the light emitted to the first region on the basis of the information about the amount of the light reflected from the first region measured by the light quantity measurement sensor, and
• where n is an integer of 2 or more.