The semiconductor industry continues to move forward with the introduction of high-k and low-k materials for use as gate dielectrics and interlayer insulators, respectively. The successful integration of these materials into the manufacturing process requires an understanding of the chemical, physical, and electrical properties of the new materials. Secondary ion mass spectrometry (SIMS) can provide valuable chemical information about high- and low-k materials, either using static SIMS to investigate surface chemistry or dynamic SIMS for depth profiling. However, these advanced materials are often complex mixtures of elements and physical phases that can complicate the analysis. This presentation will describe some of the current progress in the use of SIMS depth profiling to characterize both high- and low-k materials, and the challenges that remain. Examples from our lab will be used to demonstrate the difficulties (e.g., charging, beam damage) encountered when profiling new generation, porous low-k materials. Examples of backside SIMS to assess barrier metal diffusion will be also be shown. For high-k materials, particularly thin HfO@sub 2@ and HfSiO films, examples from our lab will be used to show the presence of several SIMS artifacts including preferential sputtering and sputter rate and ion variations. Also, the issue of dopant penetration through the films will be discussed.