What Is a Scatterometer?

An instrument that uses optical methods to measure geometric dimensions such as the line width of a photoresist pattern is called a scatterometer. The working principle of scattermetry is: a beam of light is incident on the wafer surface, and the photoresist pattern on the wafer surface scatters and diffracts the incident light, and these lights containing surface structure information are received by the detector. The signal received by the detection instrument is analyzed to obtain the three-dimensional size of the photoresist pattern on the wafer surface. ^[1]