Room temperature approach to fully transparent, all-oxide thin-film transistors

Thomas Rembert and Ali Javey

EECS Department
University of California, Berkeley
Technical Report No. UCB/EECS-2015-148
May 18, 2015

http://www2.eecs.berkeley.edu/Pubs/TechRpts/2015/EECS-2015-148.pdf

In this report, a room temperature cathodic arc deposition technique to produce nanocrystalline ZnO thin films for low voltage thin film transistors (TFTs) and digital logic inverters is presented. Room-temperature deposited ZnO films exhibit high Hall mobilities exceeding 21 cm2V-1s-1. All-oxide fully transparent ZnO-channel TFTs were realized on alkali-free glass and flexible polyimide foil. Devices exhibited subthreshold swings as low as 204 mV/dec, saturation mobilities as high as µsat = 3.1 cm^2/Vs, threshold voltages between Vt = 0.36-1.2 V, and on/off current ratios of 10^5, all while operating at ±3 V. Bending studies were performed on the ZnO TFTs on polyimide, displaying retention of its original performance characteristics while bent at r = 8 mm. The all-oxide inverter is fabricated on polyimide and operates at 2 V, exhibiting a peak gain of ~ 8. The work presents a practical materials and device platform for low-temperature fabrication of TFTs with high performance on virtually any substrate.

Advisor: Ali Javey


BibTeX citation:

@mastersthesis{Rembert:EECS-2015-148,
    Author = {Rembert, Thomas and Javey, Ali},
    Title = {Room temperature approach to fully transparent, all-oxide thin-film transistors},
    School = {EECS Department, University of California, Berkeley},
    Year = {2015},
    Month = {May},
    URL = {http://www2.eecs.berkeley.edu/Pubs/TechRpts/2015/EECS-2015-148.html},
    Number = {UCB/EECS-2015-148},
    Abstract = {In this report, a room temperature cathodic arc deposition technique to produce nanocrystalline ZnO thin films for low voltage thin film transistors (TFTs) and digital logic inverters is presented. Room-temperature deposited ZnO films exhibit high Hall mobilities exceeding 21 cm2V-1s-1. All-oxide fully transparent ZnO-channel TFTs were realized on alkali-free glass and flexible polyimide foil. Devices exhibited subthreshold swings as low as 204 mV/dec, saturation mobilities as high as µsat = 3.1 cm^2/Vs, threshold voltages between Vt = 0.36-1.2 V, and on/off current ratios of 10^5, all while operating at ±3 V. Bending studies were performed on the ZnO TFTs on polyimide, displaying retention of its original performance characteristics while bent at r = 8 mm. The all-oxide inverter is fabricated on polyimide and operates at 2 V, exhibiting a peak gain of ~ 8. The work presents a practical materials and device platform for low-temperature fabrication of TFTs with high performance on virtually any substrate.}
}

EndNote citation:

%0 Thesis
%A Rembert, Thomas
%A Javey, Ali
%T Room temperature approach to fully transparent, all-oxide thin-film transistors
%I EECS Department, University of California, Berkeley
%D 2015
%8 May 18
%@ UCB/EECS-2015-148
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/2015/EECS-2015-148.html
%F Rembert:EECS-2015-148