Method of marking on metallic layer, metallic layer with marks thereon and semiconductor device having the metallic layer

1. Field of the Invention This marking method is carried out with an object to form a mark of high visibility on a surface of a metallic layer of such as a cover plate of a semiconductor device or the like without generating metallic debris or the like. According to this method, on a marking area of a metallic layer with a matte surface (R: 0.5 to 5 m), a laser beam is illuminated, thereby the metallic layer is melted, then re-solidified, thereby minute unevenness on the surface of the metallic layer is averaged and erased to be smooth. Thus formed marking portion reflects light specularly and is different in light reflectivity from an underlying portion which scatters light (diffuse reflection). Due to the difference of reflectivity, the marking portion can be visually discerned with excellency.