Metallization of High-Temperature Silicon ICs Based on Tungsten Titanium Alloy
Nowadays, one of the priority directions of development of electronics both in our country and abroad is the creation of silicon semiconductor devices and IC with the submicron topological dimensions capable of functioning at temperature 200 °C and higher. Metallization is a critical node of the silicon electronic component base from the point of view of thermal stability. Recently, as an interconnection material tungsten, which has higher electromigration resistance compared with aluminum (with silicon and copper additives) is used. In the work the results of the technological regimes research of W(Ti-15 %) alloy films magnetron sputtering have been presented. During investigating the mechanical properties of the films it has been determined that the structure W(Ti-15 %)-Si is characterized by a lower level of mechanical stresses in lateral direction compared to the built-in mechanical stresses in the W-Si structure. It has been revealed that the full force of the film of tungsten with titanium alloy approximately three times exceeds that one of the tungsten film. It has been shown that the metallization based on tungsten alloyed with titanium is characterized by a significantly higher elctromigration resistance compared to metallization based on an alloy of aluminum with copper and silicon. The results based on a comparative analysis of the electric-physical and mechanical characteristics of sputtered on silicon tungsten films and the alloy of tungsten with titanium from the point of view of using them as interconnections in heat-resistant silicon IC have confirmed their promising implementation.