Shallow junction formation by dopant outdiffusion from CoSi2 and its application in sub 0.5 mu m MOS processes

Two different methods for shallow junction formation and poly-Si doping based on outdiffusion of As, B, BF2 from CoSi2 have been evaluated in complete sub 0.5 mu m NMOS and PMOS processes. p+ and n+ junctions were processed with a total depth down to 100 nm and 140 nm, respectively. The leakage current density was measured in the range of 1E-9 Acm-2 at VR=-5 V for p+ diodes. The n+ diodes exhibit an increased leakage current at 1E-5 Acm-2. In order to evaluate the device performance, transistors with effective channel lengths down to 0.25 mu m and good static device behavior have been fabricated by means of X-ray lithography. A special outdiffusion technique is able to reduce the boron penetration through thin gate oxides >or=5 nm.