A Simple Method for High-Performance, Solution-Processed, Amorphous ZrO2 Gate Insulator TFT with a High Concentration Precursor

Abstract

Solution-processed high-k dielectric TFTs attract much attention since they cost relatively little and have a simple fabrication process. However, it is still a challenge to reduce the leakage of the current density of solution-processed dielectric TFTs. Here, a simple solution method is presented towards enhanced performance of ZrO2 films by intentionally increasing the concentration of precursor. The ZrO2 films not only exhibit a low leakage current density of 10−6 A/cm2 at 10 V and a breakdown field of 2.5 MV/cm, but also demonstrate a saturation mobility of 12.6 cm2·V−1·s−1 and a Ion/Ioff ratio of 106 in DC pulse sputtering IGZO-TFTs based on these films. Moreover, the underlying mechanism of influence of precursor concentration on film formation is presented. Higher concentration precursor results in a thicker film within same coating times with reduced ZrO2/IGZO interface defects and roughness. It shows the importance of thickness, roughness, and annealing temperature in solution-processed dielectric oxide TFT and provides an approach to precisely control solution-processed oxide films thickness.

Properties-Adjustable Alumina-Zirconia Nanolaminate Dielectric Fabricated by Spin-Coating

“…The result measured by XRD showed that the ZrO 2 has already crystallized and the corresponding crystallization peaks were shown in Figure 8a [22]. That was the main reason why ZrO 2 was easier to break down.…”

Effect of Annealing Environment on the Performance of Sol–Gel-Processed ZrO2 RRAM

“…In particular, we could increase the HRS by approximately 10 times due to the decreased current leakage. The annealing process in a vacuum permitted the formation of denser films and high oxidation states with a small number of oxygen vacancies in ZrO 2 films with a low leakage current [17]. Figure 4c,d shows the distribution of the representative parameters, such as the HRS, LRS, SET voltage, and RESET voltages.…”

Bias Stability Enhancement in Thin-Film Transistor with a Solution-Processed ZrO2 Dielectric as Gate Insulator

“…ZrO 2 solution was synthesized by dissolving ZrCl 2 O•8H 2 O (Richjoint, Shanghai, China) in a 2-methoxyethanol (2ME) (Fuyu Fine Chemical, Tianjin, China) solvent. The solution was stirred at 300 r/min at room temperature for 2 h, and was then aged for at least one day [25]. The precursor solution was spin-coated on the indium tin oxide (ITO) substrate at 5000 rpm for 40 s. If multiple spin-coating was used, the wet films were pre-annealed at 300 • C for 5 min after each spin.…”

“…Nowadays, a number of high-k metal-oxide dielectrics (such as Al 2 O 3 [7], ZrO 2 [8], HfO 2 [9], TiO 2 , Y 2 O 3 [10], Ta 2 O 5 and CeO 2 ) have been widely studied and used as an alternative to conventional SiO 2 dielectric layers (k = 3.9) with low leakage current density. Among these gate oxides, zirconium oxide (ZrO 2 ) is one of the attractive materials because of its excellent physical properties, for example, high dielectric constant (23)(24)(25)(26)(27)(28)(29), good thermal stability, wide band gap (5-7 eV), and large transparency in the visible and infrared ranges [11,12].…”