Destruction of Metallization Systems on Silicon From Overheating to Melt Migration

Abstract

Abstract:The article introduces the analysis of thermal degradation mechanisms related to the heating and melting of metallization system, as well as the contact fusion in transient conditions, and carries out an investigation of the thermal damage of metallization systems under the influence of current pulses. The method of pulse impact on the structure of the metal-semiconductor. The results showed that both thickness and thermal conductivity of the underlayer strongly influence the dynamics of heating of the multilayer system. The results obtained during the experiments show that the various heat-conducting properties of the SiO2 and Si3N4 films are clearly reflected in the connection oscillograms. As a result of defects, a local reduction of the film cross-section leads to an increase in current density, temperature, and consequently, appearance of a local molten area. Electron microscopy confirmed the presence of contact melting at the interface Al-Si. Phase analysis conducted in the border region has shown that the amount of Si impurities in the eutectic makes about 63%. The occurrence of the interface temperature gradients leads to stress, which contributes to the formation of structural defects near the source of thermal shock. The resulting temperature gradient causes the thermoelastic critical condition that could lead to a violation of the adhesion of the metal film, the formation of structural defects and failure of the test compound. The experimental results of thermal degradation of metallization systems, as well as the calculation of physical indicators are described.