TY - JOUR
T1 - Water-Induced Scandium Oxide Dielectric for Low-Operating Voltage n- and p-Type Metal-Oxide Thin-Film Transistors
AU - Liu, Ao
AU - Liu, Guoxia
AU - Zhu, Huihui
AU - Song, Huijun
AU - Shin, Byoungchul
AU - Fortunato, Elvira
AU - Martins, Rodrigo
AU - Shan, Fukai
N1 - This work was supported by the Natural Science Foundation of China (Grant nos. 51472130 and 51572135).
PY - 2015/12/9
Y1 - 2015/12/9
N2 - Solution-processed metal-oxide thin films based on high dielectric constant (k) materials have been extensively studied for use in low-cost and high-performance thin-film transistors (TFTs). Here, scandium oxide (ScOx) is fabricated as a TFT dielectric with excellent electrical properties using a novel water-inducement method. The thin films are annealed at various temperatures and characterized by using X-ray diffraction, atomic-force microscopy, X-ray photoelectron spectroscopy, optical spectroscopy, and a series of electrical measurements. The optimized ScOx thin film exhibits a low-leakage current density of 0.2 nA cm-2 at 2 MV cm-1, a large areal capacitance of 460 nF cm-2 at 20 Hz and a permittivity of 12.1. To verify the possible applications of ScOx thin films as the gate dielectric in complementary metal oxide semiconductor (CMOS) electronics, they were integrated in both n-type InZnO (IZO) and p-type CuO TFTs for testing. The water-induced full oxide IZO/ScOx TFTs exhibit an excellent performance, including a high electron mobility of 27.7 cm2 V-1 s-1, a large current ratio (Ion/Ioff) of 2.7 × 107 and high stability. Moreover, as far as we know it is the first time that solution-processed p-type oxide TFTs based on a high-k dielectric are achieved. The as-fabricated p-type CuO/ScOx TFTs exhibit a large Ion/Ioff of around 105 and a hole mobility of 0.8 cm2 V-1 at an operating voltage of 3 V. To the best of our knowledge, these electrical parameters are among the highest performances for solution-processed p-type TFTs, which represents a great step towards the achievement of low-cost, all-oxide, and low-power consumption CMOS logics.
AB - Solution-processed metal-oxide thin films based on high dielectric constant (k) materials have been extensively studied for use in low-cost and high-performance thin-film transistors (TFTs). Here, scandium oxide (ScOx) is fabricated as a TFT dielectric with excellent electrical properties using a novel water-inducement method. The thin films are annealed at various temperatures and characterized by using X-ray diffraction, atomic-force microscopy, X-ray photoelectron spectroscopy, optical spectroscopy, and a series of electrical measurements. The optimized ScOx thin film exhibits a low-leakage current density of 0.2 nA cm-2 at 2 MV cm-1, a large areal capacitance of 460 nF cm-2 at 20 Hz and a permittivity of 12.1. To verify the possible applications of ScOx thin films as the gate dielectric in complementary metal oxide semiconductor (CMOS) electronics, they were integrated in both n-type InZnO (IZO) and p-type CuO TFTs for testing. The water-induced full oxide IZO/ScOx TFTs exhibit an excellent performance, including a high electron mobility of 27.7 cm2 V-1 s-1, a large current ratio (Ion/Ioff) of 2.7 × 107 and high stability. Moreover, as far as we know it is the first time that solution-processed p-type oxide TFTs based on a high-k dielectric are achieved. The as-fabricated p-type CuO/ScOx TFTs exhibit a large Ion/Ioff of around 105 and a hole mobility of 0.8 cm2 V-1 at an operating voltage of 3 V. To the best of our knowledge, these electrical parameters are among the highest performances for solution-processed p-type TFTs, which represents a great step towards the achievement of low-cost, all-oxide, and low-power consumption CMOS logics.
KW - dielectric properties
KW - metal oxides
KW - thin films
KW - transistors
UR - http://www.scopus.com/inward/record.url?scp=85000398886&partnerID=8YFLogxK
U2 - 10.1002/adfm.201502612
DO - 10.1002/adfm.201502612
M3 - Article
AN - SCOPUS:85000398886
SN - 1616-301X
VL - 25
SP - 7180
EP - 7188
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 46
ER -