Electronic transport properties of amorphous indium-gallium-zinc oxide semiconductor upon exposure to water

The effect of water exposure on amorphous indium-gallium-zinc oxide (a-IGZO) semiconductors was reported. It was found that water can diffuse in and out of the a-IGZO film, reversibly affecting the transistor properties. Two competing mechanisms depending on the thickness of the active channel were clarified. The electron donation effect caused by water adsorption dominated for the thicker a-IGZO films (⩾100nm), which was manifested in the large negative shift (>14V) of the threshold voltage. However, in the case of the thinner a-IGZO films (⩽70nm), the dominance of the water-induced acceptorlike trap behavior was observed. The direct evidence for this behavior was that the subthreshold swing was greatly deteriorated from 0.18V/decade (before water exposure) to 4.4V/decade (after water exposure) for the thinnest a-IGZO films (30nm). These results can be well explained by the screening effect of the intrinsic bulk traps of the a-IGZO semiconductor.

[1]  Yeon-Gon Mo,et al.  High mobility bottom gate InGaZnO thin film transistors with SiOx etch stopper , 2007 .

[2]  Daihua Zhang,et al.  Electronic transport studies of single-crystalline In2O3 nanowires , 2003 .

[3]  Benjamin J. Norris,et al.  ZnO-based transparent thin-film transistors , 2003 .

[4]  E. Fortunato,et al.  Fully Transparent ZnO Thin‐Film Transistor Produced at Room Temperature , 2005 .

[5]  Changjung Kim,et al.  Amorphous gallium indium zinc oxide thin film transistors: Sensitive to oxygen molecules , 2007 .

[6]  Cherie R. Kagan,et al.  Operational and environmental stability of pentacene thin-film transistors , 2005 .

[7]  H. Ohta,et al.  Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors , 2004, Nature.

[8]  J. Boyle,et al.  The effects of CO, water vapor and surface temperature on the conductivity of a SnO2 gas sensor , 1977 .

[9]  Yeon-Gon Mo,et al.  Improvements in the device characteristics of amorphous indium gallium zinc oxide thin-film transistors by Ar plasma treatment , 2007 .

[10]  D. Greve.  Field Effect Devices and Applications: Devices for Portable Low Power, and Imaging Systems , 1998 .

[11]  Cherie R. Kagan,et al.  Thin-Film Transistors , 2007 .

[12]  Q. Wan,et al.  Electronic transport through individual ZnO nanowires , 2004 .

[13]  Z. Fan,et al.  ZnO nanowire field-effect transistor and oxygen sensing property , 2004 .

[14]  Oana D. Jurchescu,et al.  Electronic transport properties of pentacene single crystals upon exposure to air , 2005 .

[15]  Evidence of water-related discrete trap state formation in pentacene single-crystal field-effect transistors , 2005, cond-mat/0508607.

[16]  Bias-dependent generation and quenching of defects in pentacene. , 2003, Physical review letters.

[17]  Noboru Yamazoe,et al.  Interactions of tin oxide surface with O2, H2O AND H2 , 1979 .

[18]  Y. Shimizu,et al.  Humidity‐Sensitive Characteristics of La3+‐Doped and Undoped SrSnO3 , 1989 .