| About this Abstract |
| Meeting |
2011 Electronic Materials Conference
|
| Symposium
|
2011 Electronic Materials Conference
|
| Presentation Title |
P5, Low-Temperature Processed Schottky-Gated Field-Effect Transistors Based on Amorphous Gallium-Indium-Zinc-Oxide |
| Author(s) |
Michael Lorenz, Alexander Lajn, Heiko Frenzel, Holger von Wenckstern, Marius Grundmann, Pedro Barquinha, Elvira Fortunato, Rodrigo Martins |
| On-Site Speaker (Planned) |
Michael Lorenz |
| Abstract Scope |
We demonstrate metal-semiconductor field-effect transistors (MESFET) based on amorphous oxide channel material. The gallium-indium-zinc-oxide (GIZO) thin films and the AgxO-Schottky gate electrodes were deposited at room-temperature. Annealed thin film devices exhibit a subthreshold swing of S = 112 mV/decade and gate sweep voltages of 2.4 V. The field-effect mobility is 15 cm²/Vs and on-off-current ratios > 10<SUP>7</SUP> are achieved. Compared to as-grown thin film transistors increased reproducibility and lower gate leakage currents are attained on annealed thin films. Oxide based electronics have recently gained more attention in the research, e.g. due to their applicability in transparent electronics. The current research in this field is entirely focused on metal-insulator-semiconductor field-effect transistors. We demonstrate that the MESFET device concept is not only compatible with polycrystalline zinc oxide thin films, but also with amorphous oxide channel materials. GIZO thin films were grown by radio frequency magnetron sputtering at room temperature on Corning 1737 glass substrates. Subsequent annealing at 150 °C has strong effects on the electrical properties of the thin films (e.g. Hall-effect mobility) and on device characteristicts of the transistors, e.g. increased field-effect mobility. The MESFET were fabricated by standard photolithography using lift-off technique. The ohmic source and drain electrodes were sputtered using an Au target in an argon atmosphere. The Schottky gate contacts were sputtered by means of an Ag target in a mixed argon/oxygen atmosphere, which yields a partial oxidization of Ag and hence to higher effective barrier heights for the Schottky contact. The effective barrier height of the Schottky contacts on GIZO channel material, extracted assuming thermionic emission only, is 0.95 eV. The ideality factors of contacts on GIZO were determined for the annealed thin films to be n = 1.9 and for the as-grown thin film n = 2. |
| Proceedings Inclusion? |
Undecided |