Electronic polymer devices and test structures based on PEDOT/PSS were fabricated in a fully CMOS compatible process. The resistivity of PEDOT/PSS polymer films is dependent on film thickness. The resistivity increases with decreasing film thickness for polymer film thicknesses between 190 nm and 380 nm. The resistivity differs by a factor of ~3 depending on film thickness. The evaluation of the specific contact resistivity depending on the choice of the metallization leads to a difference of the specific contact resistivity by a factor of 190. The specific contact resistivity does not follow the Schottky-Mott law and thus indicates a non-ideal behavior of the metal PEDOT/PSS interface. The lowest average specific contact resistivity was obtained for silver with an average value of 0.14 Ωcm2 and the highest specific contact resistivity was obtained for platinum. Even the lowest specific contact resistivity for silver is still very high when compared with low resistivity ohmic contacts to silicon. However, the specific contact resistivity is expected to have a significant drawback for overall device performance. Possible future applications of MEMS and electronics based on polymers will be for simple devices like transistors, ID tags, thermistors, acceleration and pressure sensors as well as radiation and UV detectors.
In this overview the mechanical, thermal and electrical properties of CVD (Chemical Vapor Deposition) diamond, determined by various non-destructive techniques, are highlighted and compared with calculations. In the case of Young's modulus the measurement results of high quality samples leads to an average value of 1126 GPa which is in good agreement with the calculated value of 1143 GPa and close to the Young+s modulus of single crystalline diamond. However, values as low as 242 GPa were determined on 300 +m thick bulk CVD diamond. The differences in the measurement results can be traced back to extended voids in the sample. A traditional heated bar technique was used to measure the temperature dependent thermal conductivity of CVD-diamond. High quality polycrystalline diamond films reached a room temperature thermal conductivity of 20.5 W cm-1 K-1. This value is comparable to the thermal conductivity of the best single crystal diamonds available. For the lower quality samples, boundary scattering and point defects are most likely responsible for the lower thermal conductivity. The electrical properties of B-doped polycrystalline diamond films were characterized by temperature dependent Hall and conductivity measurements. These measurements together with a semi-empirical model give insight in to the current transport mechanism. The model indicates, that the electrical mobility in diamond thin films is lower compared with single crystal diamond. However, the current conduction mechanism are essentially the same when compared with single crystal diamond.