Bottom Palladium Quasi-Ohmic Contact to Atomic Layer Deposited Zinc Tin Oxide Thin Film

We report using evaporated palladium (Pd) to create a quasi-ohmic bottom contact to an atomic layer deposited zinc tin oxide semiconductor film. Vertical conduction test structures show that current scales with device area. A maximum current density of 165 A/cm2was achieved at a bias voltage of +1 V. The specific contact resistance between the bottom Pd and zinc tin oxide is found to be 6.43 × 10-3Ωcm2. Measurements between adjacent bottom Pd contacts show linearI-Vbehavior. These results indicate that the bottom Pd contact is quasi-ohmic. In the future, such vertical conducting structures can be used in emerging device applications such as high-density vertical back end of line oxide transistors and two-transistors-zero-capacitor (2T0C) DRAM.