Influence of Metal Contamination on Minority Carrier Diffusion Length and Oxide Charge

Many kinds of ULSI Circuit (DRAM, LOGIC, FRAM [1] etc.) are produced at the same production line to reduce the costs. So we have to control many kinds of metal contamination. We investigated the influence of metal contamination on minority carrier diffusion length and oxide charge. The metal impurities we studied are Fe, Cu, Ni, Cr, Al, Na, Ca, FRAM electrode metals (Pt, Ru), metals included in PZT ferro-electric capacitors (Pb, Zr, Ti) [2], metals added to PZT (La, Nb) [3], and metals used for SBT Ferro-electric capacitors (Sr, Bi, Ta) [4].