1. Resistivity Properties of interconnect materiak resistivity Which material Melting point (C) is better for local and which for 40-70 28-35 15-20 polysilicon(heavily doped) Properties of commonly used interconnected materials in both Si and GaAs technologies Material Bulk Resistivity(uf2-cm Melting Point (C) LAu use for gaAs 2. Ohmic and Schottky junctie ons Even after selecting conductor material no guarantee it will make good electrical contact to Si, GaAs, etc Nature of contact depends on charge transfer at metal/semiconductor interface charging = band bending bending depends on work functions, m, and electron affinity, x Vacuum E Metal n-type semiconductor ll/703 3.155J6.l52J3 11/17/03 3.155J/6.152J 5 1. Resistivity Which material is better for local and which for global interconnects? use for GaAs 11/17/03 3.155J/6.152J 6 2. Ohmic and Schottky junctions Even after selecting conductor material, no guarantee it will make good electrical contact to Si, GaAs, etc. Nature of contact depends on charge transfer at metal/semiconductor interface; charging => band bending & bending depends on work functions, fm , fs and electron affinity, c. Ef Energy Metal n-type semiconductor Vacuum fm c fs Ef Ec Ev