title: Using chemical-mechanical polishing for planarizing a high-kappa nanocomposite polyimide insulator for organic thin film transistors application.
abstract: To solve the large leakage current of the heavily blended nanocomposite (Polyimide and nano-TiO2 particles) gate dielectric film exhibiting a high-kappa, the chemical-mechanical polishing (CMP) was adopted to flatten the surface of the PI-TiO2 nanocomposite film. An extremely high dielectric constant (is congruent to 13) of the nanocomposite with CMP treatment is obtained and its leakage current is comparable to that of the neat polyimide in our studies. An OTFT based on the nanocomposite gate dielectric exhibiting high capacitance and a smooth surface after CMP treatment shows very promising performance. Compared with the OTFT based on the neat polyimide gate dielectric, the threshold voltage is improved from -22 to -5 (V), the sub-threshold voltage is decreased from 3.44 to 0.50 (V/dec), the current on/off ratio is increased from 1.6 x 10(6) to 3.53 x 10(8), and the mobility is increased from 0.416 to 0.624 (cm2V(-1)s(-1)). Moreover, it is worth noting that the hysteresis effect of OTFT based the nanocomposite can be significantly reduced due to the few charge trapped in the interface when the nanocomposite dielectric surface was further polished by CMP treatment.
authors: Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
authors: Wen-Hsi
authors: WH
authors: Lee
authors: Chun Chieh
authors: CC
authors: Wang
authors: Sao-De
authors: SD
authors: Liu
mesh_terms: D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007094:Imides / Q000737:chemistry*; D008422:Materials Testing; D008567:Membranes, Artificial; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation*; D009930:Organic Chemicals / Q000737:chemistry*; D013499:Surface Properties; D014173:Transistors, Electronic
chemical_list: D007094:Imides; D008567:Membranes, Artificial; D009930:Organic Chemicals