Characterization of the Co-Silicide Penetration Depth into the Junction Area for 0.15 and Sub-0.15 Micron CMOS Technology

Abstract

The penetration depth of cobalt silicide layer in shallow junction is assessed using the current–voltage curve both in reverse and forward bias regions. The reverse leakage current characteristics said that silicide has affected both of the areal and peripheral intensive n+/p diodes because the leakage current is increased about one order of magnitude by silicidation. In case of p+/n junction, there is no increase of reverse leakage current. In case of forward region, however, only the forward current of peripheral intensive diode was increased by silicidation. From the different junction current behavior in forward and reverse bias region, it can be said that the penetrated depth of silicide layer is almost near to the space charge region but not into it for area diode. However, in case of peripheral intensive diode, silicide has penetrated into the space charge region. The Schottky contact area formed by silicide penetration is extracted as 3.02 µm2. The extracted Schottky barrier for n+/p parameter diode is 0.63 eV which is quite similar to the theoretical value of 0.64 eV.