Patent ID: 8643836

Claim:
An inspection method for inspecting defects of wafer surface, wherein the wafer surface has a predetermined lattice orientation, the method comprising: encircling peripheral region of the wafer surface by a first light source set and a second light source set; using a control module to control the first light source set and the second light source set to irradiate light alternately from different directions; using an image pick-up module to receive a scattered light image during each time when the first light source set or the second light source set irradiates the light on the wafer surface; and using a process module to obtain a defect image of the wafer surface by processing each of the scattered light images; wherein the first light source set comprises a first light source and a third light source opposite to the first light source, the second light source set comprises a second light source and a forth light source opposite to the second light source, and the step of using the control module further comprises controlling the first light source and the third light source to irradiate the light simultaneously, and then controlling the second light source and the forth light source to irradiate the light simultaneously.