IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Dielectrics Wednesday Sessions
       Session DI-WeA

Paper DI-WeA7
Temperature-dependent Current Transport in Low-k Inorganic Polymer Dielectrics

Wednesday, October 31, 2001, 4:00 pm, Room 130

Session: Low K Dielectrics
Presenter: J.W. Tringe, U.S. Air Force Research Laboratory
Authors: J.W. Tringe, U.S. Air Force Research Laboratory
R.A.B. Devine, U.S. Air Force Research Laboratory
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Low-k dielectrics are an increasingly important class of materials for high-performance integrated circuits, promising to significantly increase processing speeds by lowering resistance-capacitance delays in global interconnects. However, since these new dielectrics are anticipated to cover large areas of the chip they also represent a potential reliability risk. It is therefore important to understand how charge transport occurs in the low-k films over a range of temperatures in order to avoid breakdown or excess leakage current during circuit operation. Low-k dielectric films based on inorganic polymers such as FOx flowable oxide from Dow Corning have been examined. Spun-on films, 3000 Å thick, were patterned into metal-insulator-semiconductor capacitor structures, then probed to measure current and capacitance as a function of voltage. Temperature-dependent current-voltage measurements, over the range 26 to 150 °C, show that current conduction is predominately via either Schottky or Frenkel-Poole emission. A field-independent thermally activated barrier height of approximately 0.1-0.2 eV is deduced. The measured exponential term proportional to the square root of the electric field in the current-voltage dependence is smaller than expected for Frenkel-Poole emission, however. Additionally, the temperature and field dependences of the exponential prefactor do not enable us to clearly distinguish between Schottky or Frenkel-Poole emission over the experimental temperature range.