Electro-mechanical properties of metal-insulator-metal device fabricated on polymer substrate using low-temperature process

High-performance metal-insulator-metal (MIM) devices on flexible polymer substrates were successfully fabricated without any defects such as cracks, delamination and blistering. This work examines the mechanical and electrical properties of MIM devices constructed using anodic Ta₂O₅ films. Using newly developed methods including stepped heating process and low-temperature post-annealing below 180°C, we obtained high-performances MIM devices on polymer substrates. Here, we propose the use of stacked bottom electrode and water barrier layer in order to enhance the ductility of the Ta electrode and to prevent blistering problems, respectively. Rutherford backscattering spectroscopy (RBS), auger electron spectroscopy (AES) and transmission electronic microscope (TEM) observations were performed for the structural investigation of the MIM devices on polymer substrates. Electrical measurements were also carried out for as-deposited and thermally treated MIM devices including Al/Ta/Ta₂O₅/Cr or Ti structures. They exhibit a low leakage current (below 10^-7 A/cm² at 2 MV) and reasonable breakdown voltage (5-7MV/cm) with a uniformity of 92%. Finally, under low-temperature post-annealing conditions, The Current-Voltage (I-V) behaviors and conduction mechanisms of MIM devices on polymer substrates are discussed based on the results of electrical measurements, structural investigations and conduction band modeling.