Performance of refractory metal multilevel interconnection system

High-temperature multilevel interconnection systems are discussed from a materials fabrication, yield, and circuit performance point of view. Refractory metal interconnections are compared to diffused Si planar runs and heavily doped polycrystalline Si films. Circuit configurations and their relative importance for these material-circuit performance considerations are considered. All of the high-temperature refractory systems will have higher yield and better passivation properties than many low-temperature systems. Metallic interconnections are always best from a circuit performance point of view. The relative difference between the high-temperature systems considered depends on circuit configuration. In particular, high-temperature refractory metal (Mo, W) interconnections which are a natural by-product of the self-registered refractory metal gate MOS technology (RMOS) are superior for memory circuits where long address lines are used.