An apparatus and method for automatically collecting metallic impurities of a semiconductor wafer. In one aspect, an apparatus includes an air tight process chamber including a loading unit for loading the semiconductor wafer and unloading unit for unloading the semiconductor wafer; a vapor phase decomposition unit disposed in the process chamber for decomposing a silicon oxide layer on the semiconductor wafer; and a scanning unit disposed in the process chamber for scanning the semiconductor wafer to collect the metallic impurities. The scanning unit includes a scanning solution bottle for obtaining scanning solution that is used for absorbing metallic impurities on the semiconductor wafer; a scanning arm capable of downward, upward, and rotational movement; and a nozzle coupled to the scanning arm for drawing in scanning solution from the scanning solution bottle, and for forming a droplet of scanning solution that cohers to the nozzle when scanning a semiconductor wafer to collect metallic impurities.