Reliability improvements of thin film platinum resistors on wafer-level and micro-hotplates at stress temperatures in the range of 140-290 ℃

摘要

In this work, we present the improvement of thermal long-term reliability of platinum resistors through transition from a quasi-stoichiometric SiO2 layer to silicon-rich SiOx cover layers. The physical effects were investigated on a platinum meander test structure using a wafer-level based approach. As a result, reliability can be studied simultaneously on several hundreds of chips with a great statistical certainty. In addition, possible influences of chip dicing and packaging technology can be avoided. The activation energy for drift is extracted from a linear fit to the Arrhenius diagram. Furthermore, a comparison of drift data with an analytical equation is done as proposed in literature. Investigations with resistors on fabricated micro-hotplates exemplify the validity of improving the long-term reliability even on device-level.