Deposition of Multi-Functional Coatings by Physical Vapour Deposition
Multifunctional coatings open new dimensions due to a combination of properties like high friction and wear resistance, electrical attributes, heat or corrosion protection in one system. In this study multifunctional coatings for in-situ temperature measurements on cutting inserts as well as multilayer coatings have been investigated. Corresponding metallurgical analyses together with mechanical tests are presented.
It is found that a spurious leakage path from the emitter to the collector of a lateral p-n-p or a trench-defined n-p-n device may be induced by the applied collector voltage. This voltage influences the surface potential at the emitter-base junction through the charging of the polyimide used as interlevel dielectric or as trench fill, respectively. A simple model of the effect is developed, and several successful process features are discussed. >