Abstract This paper presents the post-annealing effects, caused by rapid thermal annealing (RTA), on amorphous indium gallium zinc oxide (a-IGZO) thin film transistor's (TFT) electrical characteristics, and its contact resistance ( R C ) with thermally grown SiO 2 gate dielectric on silicon wafer substrates. The electrical characteristics of two types of TFTs, one post-annealed and the other not, are compared, and a simple model of the source and drain contacts is applied to estimate the R C by a transmission line method (TLM). Consequently, it has been found that the post-annealing does improve the TFT performances; in other words, the saturation mobility ( μ sat ), the on/off current ratio ( I ON/OFF ), and the drain current ( I D ) all increase, and the R C and the threshold voltage ( V T ) both decrease. As-fabricated TFTs have the following electrical characteristics; a saturation mobility ( μ sat ) as large as 0.027 cm 2 /V s, I ON/OFF of 10 3 , sub-threshold swing (SS) of 0.49 V/decade, V T of 32.51 V, and R C of 969 MΩ, and the annealed TFTs have improved electrical characteristics as follows; a μ sat of 3.51 cm 2 /V s, I ON/OFF of 10 5 , SS of 0.57 V/decade, V T of 27.2 V, and R C of 847 kΩ.

The effect of annealing on amorphous indium gallium zinc oxide thin film transistors

Indium-tin-zinc-oxide (ITZO) as the channel layer grown by co-sputtering of ZnO target and ITO target in the bottom gate thin-film transistors (TFTs) is proposed in this work. The microstructure and optical properties of ITZO thin films at different annealing temperatures were analyzed. The impact of various annealing temperatures on the ITZO TFT performance characteristics was systematically investigated as well. It was found that ITZO TFT with annealing temperature of 300 °C exhibits excellent electrical performance with a high saturation field-effect mobility (μsat) of 27.4 cm2 V−1 s−1, a low threshold voltage (Vth) of −0.64 V, a small subthreshold swing (SS) value of 0.23 V per decade, and the high on-off current ratio (Ion/Ioff) of 1.8 × 107. In addition, it also shows good output curves including gate control capabilities and good electrode contact as well as extreme atmospheric stability. As shown by photoluminescence (PL) analysis and X-ray photoelectron spectroscopy (XPS) analysis, the beneficial effects of various annealing temperatures on device performance are attributed to the reorganization of the amorphous network and the control of defect chemistry in the films. The correlation between the post-deposition thermal treatment and the characteristics of a transistor was investigated and excellent performance of the transistor was demonstrated.

/pdf/effects-of-annealing-temperature-on-properties-of-insnzno-1o3hrptgic.pdf

Effects of annealing temperature on properties of InSnZnO thin film transistors prepared by Co-sputtering

Preparation and electrical properties of N-doped ZnSnO thin film transistors

Solution processing of amorphous oxide semiconductors (AOS) is used for electronic and optoelectronic applications. However, the device performance is much lower than that for a device that is fabricated using vacuum processing. This study uses acetylacetone (acac) as an additive in the precursor solution to reduce the nanocluster size in a ZnSnO (ZTO) film. A metal-semiconductor-metal (MSM)-type UV photodetector (PD) is fabricated using as-prepared ZTO film. ZTO film that features a smaller nanocluster size, so more oxygen vacancies are induced, which produces more electrons and the photocurrent is increased. The surface at the metal/semiconductor interface is smoother so there is greater contact with fewer interface states and the dark current is decreased. An extremely high photo-to-dark current ratio (PDCR) of 1314 is achieved for a solution-processed ZTO MSM-type PD.

High-performance metal-semiconductor-metal ZnSnO UV photodetector via controlling the nanocluster size.

Implementation of ZnSnO3 nanosheets and their RE (Er, Eu, and Pr) materials: Enhanced photocatalytic activity

Preparation and electrical characteristics of N-doped In-Zn-Sn-O thin film transistors by radio frequency magnetron sputtering

Fabrication and electrical characteristics of Li-N co-doped InZnO TFTs prepared by radio frequency magnetron

In this paper, the authors attempt to fabricate thin film transistors using Li doped MgZnO (MgZnO:Li) as the active layer. The MgZnO:Li films were deposited by the radio frequency magnetron sputtering technique at room temperature. As the ideal active layer thickness is controlled at 35 nm, the mechanism on the electrical characteristic transition induced by Ar/O2 mixed plasma treatment was discussed. The results confirm that the appropriate sputtering Ar/O2 gas flow ratio (30/3) could compensate for the intrinsic defects in the channel, which is beneficial to MgZnO:Li thin film transistors. In addition, the fabricated device exhibited the best performance with a saturation mobility of 12.9 cm2/V s, a threshold voltage of −15 V, and a large on/off current ratio of 2.5 × 107.

Preparation and effects of O2 flow on the electrical characteristics of Li doped MgZnO thin film transistors

The invention provides a manufacturing method of a zinc indium tin oxide-based film transistor and aims to manufacture a transparent film transistor. The method comprises steps that a substrate is connected with a bottom grid or a source and a drain, an insulation layer is connected with the grid and an active layer, the insulation layer completely contacts with the active layer, the active layeris connected with the insulation layer, the source and the drain, the insulation layer with the thickness of 30-300nm is prepared, the ZnxInySnzO:(Lia, Nb) active layer with the thickness of 10-50 nmis prepared, targets of the ZnxInySnzO:(Lia, Nb) comprise ZnO, In2O3, SnO2, Li2O, and Zn2N3, the x is greater than 0 and is not greater than 2, the y is greater than 0 and is not greater than 2, the zis greater than 0 and is not greater than 0.5, the a is not smaller than 0 and is not greater than 0.1, the b is not smaller than 0 and is not greater than 0.1, the active layer is prepared through magnetron sputtering, the sputtering power is 75-200W, the oxygen/argon pressure ratio is 0-30%, the growth temperature is in a range of room temperature to 300 DEG C, the annealing temperature is in arange of room temperature to 350 DEG C, and the annealing atmosphere is the air, nitrogen or oxygen. The method is advantaged in that the structure is simple, design is reasonable, and problems of low mobility of commercial film transistors and high preparation temperature of high mobility film transistors are solved.

Qi Wang

Papers

Preparation and electrical properties of N-doped ZnSnO thin film transistors

Preparation and electrical characteristics of N-doped In-Zn-Sn-O thin film transistors by radio frequency magnetron sputtering

Fabrication and electrical characteristics of Li-N co-doped InZnO TFTs prepared by radio frequency magnetron

Preparation and effects of O2 flow on the electrical characteristics of Li doped MgZnO thin film transistors

Zinc indium tin oxide-based film transistor and manufacturing method thereof