Paper NS+EM-MoM1
ZnO Nanowire Logic Inverter with the Difference of Two Gate Electrode

Monday, October 31, 2011, 8:20 am, Room 203

Recently, zinc oxide nanowires (ZnO NWs) have attracted much attention for high mobility and sensing properties. These advantageous give us strong possibility to use nanostructures as nanoelectronic device application; such as field effect transistors (FETs), diodes, and logic circuit devices.[1] In this work, we fabricated the logic circuit inverter using difference of gate electrodes which have the different work function.[2]

In order to fabricate the inverter devices, grown ZnO NWs were dispersed to the SiO₂/Si substrate by using a drop-and-dry method. The Ni/Ti source and drain electrodes were deposited by e-beam evaporator with a combination of photo-lithography and lift-off process. To make 30nm-thick Al₂O₃ gate insulator layer, we used Atomic Layer Deposition (ALD) system. And then, Pd and Ni/Ti top gate electrodes were deposited and these two devices were connected by wire bonding technique.

The threshold voltage of the Pd top gate ZnO NWs FET shows more positive value (~ 0 V) than that of the other FET (~ -1 V) with Ni/Ti top gate, and these transistors are able to be used as a driver and a load, respectively. The linear mobility of the driver shows about 119 cm²/Vs at V_D = 0.6 V and the inverter device has high gain value of ~15 at V_DD = 5 V. Furthermore, the dynamic property of the logic inverter was measured under the 5 V square input voltages.

More details will be discussed in the meeting.

References

1. G.J, W. K. Hong, J.S. Maeng, M.H. Choe, W.J. Park, and T. K. Lee, Appl. Phys. Lett. 94 173118 (2009)

2. K.M. Lee, J.H. Kim and S.I. Im, Appl. Phys. Lett. 88, 023504 (2006)