| abstract |
Impurities arising from ion implantation processes employed for semiconductors, are removed by etching which removes a surface layer from the semiconductor. The depth of the layer removed is pref. up to 10% of the depth of the doped zone formed by ion implantation. The etching is pref. carried out by etching in HF; or anodic oxidn. of layer, then etching with HF; or by plasma-, ion beam-, or sputter-etching. In mfg. semiconductor devices, ion implantation often carries impurities into the substrate. These impurities can be e.g. Fe, arising from screens, diaphragms, etc. in the ion implantation appts., the impurities poison the semiconductor and must be removed. |