SIMULATION OF ULTRA SHALLOW JUNCTION FORMATION FOR NANO DEVICES APPLICATIONS BY DOPANT DIFFUSION FROM SPIN ON GLASSES

For realizing deep submicron MOSFETs, ultra shallow junctions with low sheetresistance and high doping concentrations are required to suppress short channel effects andto increase the performance. In this paper, ultra shallow junctions were simulated usingATHENA software package from Silvaco TCAD Tools to model the diffusion from spin ondopant (SOD) into silicon. High performance 40 nm P+N shallow junction fabricated byrapid thermal diffusion of B150 into silicon have been obtained. The junction showed verygood characteristics with leakage currents as low as 0.5 nA/cm2. Shallow junctions less than20 nm have also been obtained but the quality was not very good due to very high surfaceleakage current. Junction formation by diffusion of polysilicon layer on Si substrates thenSOD layer deposition on top of it produced shallower junctions with low sheet resistance.