Non-pattern wafer inspection device

A device to inspect a non-pattern wafer comprising:

• a light source emitting light;
• a detection unit detecting the light that is emitted from the light source and that is reflected from a wafer that comprises first and second regions;
• a support unit supporting one surface of the wafer and being movable in a vertical direction;
• and
• a judgment unit to convert the lights reflected from the first and second regions of the wafer and detected by the detection unit, into first and second quantitative measured values, respectively, to determine whether the first region of the wafer is faulty by comparing the first measured value with a first reference value, and to determine whether the second region of the wafer is faulty by comparing the second measured value with a second reference value;
• wherein the first reference value and the second reference value are different from each other;
• and
• when the first or second measured value escapes from a predetermined range, the judgment unit moves the support unit in the vertical direction so that at least one of the first measured value and second measured value is within the predetermined range.

A device to inspect a non-pattern wafer comprising:

• a light source emitting light;
• a detection unit detecting the light that is emitted from the light source and that is reflected from a center region and an edge region of a wafer;
• a support unit supporting one surface of the wafer and being movable in a vertical direction;
• and
• a judgment unit to convert the light reflected from the center region of the wafer and detected by the detection unit into a first quantitative measured value, to determine whether the center region of the wafer is faulty by comparing the first measured value with a first reference value, to convert the light reflected from the edge region of the wafer into a second quantitative measured value, and to determine whether the edge region of the wafer is faulty by comparing the second measured value with a second reference value that is different from the first reference value;
• wherein the first reference value is calculated as a sum of an average based on previously measured values that have been previously converted into quantitative measured values, respectively, by the judgment unit, and the first measured value, and a product of a standard deviation based on the previously measured values and the first measured value, and a predetermined coefficient;
• the second reference value is calculated by adding a predetermined offset value to the first reference value;
• and
• when the first or second measured value escapes from a predetermined range, the judgment unit moves the support unit in the vertical direction so that at least one of the first measured value and the second measured value is within the predetermined range.