| 摘要 |
<p>Metallic contaminants in a submicron silicon surface layer of a semiconductor wafer (105) are detected by first applying a photon flux to the wafer (105) using a high-injection surface photovoltage technique over a range of frequencies to obtain a frequency dispersion plot of the wafer. First and second optical chopping frequencies are then selected from the frequency dispersion plot, and the semiconductor wafer (105) is again radiated with the photon flux at the first selected optical chopping frequency for generation of a surface barrier height map (400) showing a distribution of charges and values of such charges on the surface layer at the selected chopping frequency. The surface layer of the semiconductor wafer (105) is then radiated again with the photon flux at the second, different optical chopping frequency for generation of a second surface barrier height map (500) of the wafer. The wafer (105) is the annealed, and the process is repeated for generation of a frequency dispersion plot and surface barrier height maps (700, 800) for the annealed wafer. The frequency dispersion plots and surface barrier height maps (700, 800) generated for the annealed wafer are compared with the plots and maps (400, 500) generated for the un-annealed wafer in order to gauge the level of metal contaminants in the submicron surface layer of the wafer. <IMAGE></p> |
