Development of oxide thin-film transistor using all spin-on-glass insulators with addition of hydrogen peroxide: Buffer, gate insulator, and interlayer dielectric

Abstract

A top-gate oxide thin-film transistor (TFT) with all spin-on-glass (SOG) insulators was developed. The SOG is based on methyl siloxane and was used for the buffer layer, gate insulator, and interlayer dielectric instead of a vacuum process. The SOG was diluted with ethanol, and a small amount of hydrogen peroxide was added. The diluted SOG was applied to top-gate amorphous indium–gallium–zinc-oxide TFTs, and the effects of the dilution and the hydrogen peroxide added were investigated. The TFTs with the optimized SOG insulators showed a mobility of 7.1 cm2/(V·s), a threshold voltage of 0.5 V, a subthreshold slope of 0.1 V/dec, and an on/off current ratio of 3.6 × 107.

Effect of the spin-on-glass curing atmosphere on In–Ga–Zn–O thin-film transistors

“…Figure 2(a) shows the transfer characteristics of the IGZO TFTs with SOG gate insulators cured in N 2 , air, and O 2 atmospheres. The effects of the dilution of SOG are shown in Figure 2(b), in which the mobility was shown to have been improved by the dilution of SOG [10]. As the gate insulator was formed from a nondiluted SOG solution, the mobilities were less than those of the TFTs with gate insulators obtained from the diluted SOG.…”

“…Siloxane-based SOG, which contains CH 3 or C 2 H 5 with an Si-O bond, has higher viscosity and shows higher planarity than the other SOG types [3,5]. SOG has been studied as an insulator for thin-film transistors (TFTs) and flexible and large area electronics, but there have not been many studies on the use of SOG as a gate insulator in TFTs, especially oxide TFTs [6][7][8][9][10][11]. The dilution of SOG using 2-propanol and deionized (DI) water was reported to reduce the curing temperatures, and curing at 200°C was tested [6].…”

“…Also, the application of the SOG gate insulator was reported for both the ZnN and a-SiGe TFTs [9,11]. Even though several solution-based materials have been evaluated for TFTs, the SOG gate insulator is rarely applied to oxide TFTs [10,12].…”

P‐196: Late‐News Poster: Stretching Compensation Pixel Circuit for AMOLED

“…When the extracted parameters are modeled on the device, the simulation results are shown in figure 6. Therefore, a new 4T2C pixel circuit was simulated using the extracted parameters [5]. The fabricated 4T2C pixel circuit was simulated by the circuit simulation tool.…”

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“…1 shows a cross-sectional structure of the top-gate a-IGZO TFT fabricated on glass. The detailed fabrication process of the top-gate a-IGZO TFTs appears elsewhere [7]. First, a 50-nmthick a-IGZO layer was deposited by RF magnetron sputtering at room temperature and annealed at 250 ℃ in an O2 atmosphere for 1 hour after patterning to reduce the oxygen vacancies and process-related defects.…”