Polyimides for Dielectric Layers

The capability to layer interconnection levels is critical for many complex circuit designs. An organic polymer dielectric has several advantages over inorganic dielectrics in such applications. These advantages include a lower dielectric constant, ease of coating, and, in some instances, photodefinability. However, there are a number of material and processing constraints placed on the use of organic polymers. The polymer must be stable, metallizable, processable, and compatible with further processing steps. We selected a base polyimide for evaluation. The conditions of its preparation and imidization were characterized. The processing behavior was then correlated with the polymer characteristics. This work allowed identification of directions for further improvements to polyimides for dielectric applications.