Research of the light reflex surface defects detection technology

The surface defects (indentations, humps, scores) of semiconductor wafers are the major factor to affect the performance of the semiconductor devices. Moreover, these defects make the manufacturing process difficult or yield of the semiconductor devices decrease. Consequently, it is necessary to do an on-line wafers detection in the benefit of the performance and yield of the devices. Thus, developing a way suited for practical detection is the urgent affair faced to people. The optical methods are the most suited ways for surface defects detection because of their non-contact operation. We discuss a relatively unknown method of the light reflex surface defects detection technology (Makyoh (or magic-mirror) topography (MT)). The optical system that we designed achieves the detection mode of the parallel light vertical incidence for the first time. It corrects the deviation between the tradition light path and arithmetic, promotes the detection precision. A lot of experiments based on this optical system are taken to get the difference between the detection modes of vertical incidence and the oblique incidence. The experiments prove that the vertical incidence mode excels the oblique incidence mode. The MT images are also analyzed and disposed. The quantitative measurement can be realized by digital image processing technology.