Impact of cation compositions on the performance of thin-film transistors with amorphous indium gallium zinc oxide grown through atomic layer deposition

Numerical Analysis of Oxygen-Related Defects in Amorphous In-W-O Nanosheet Thin-Film Transistor

“…First, the DOS of the metal-ions s-band [10,12,23] can be modeled by conduction band tail DOS g TA (E) in Equation ( 12), and Figure 1b describes the conduction band edge intercept densities N TA and its decay energy W TA. N TA is associated with lowering the electron concentration [3].…”

“…In this simulation, we assumed g TA (E) was fixed by setting N TA at 5.0 × 10 19 cm −3 •eV −1 and W TA at 0.01 eV [32], because by controlling N d and N C , we could observe the change of electron concentration dependent on the oxygen ratio of a-IWO in later sections. On the other hand, the deep DOS of the oxygen p-band [23] can be represented by valance band tail DOS g TD (E) in Equation ( 13) and Figure 1b relating to valence band edge intercept densities N TD and its decay energy W TD . Since the transfer I D -V G curve was found not affected by deep defect N TD [32], we assumed g TD (E) was fixed by setting N TD of 8.0 × 10 20 cm −3 •eV −1 and W TD of 0.12 eV for various oxygen ratios of a-IWO [11].…”

“…Furthermore, by using the unique feature of junctionless transistors (JLTs) [21] in CMOS technology, critical control of the dopant profile of source/drain can be avoided to resolve short channel effects (SCEs), such as the instability in threshold voltage (V TH ) as the channel length (L) scales down to a nanometer scale scheme. Additionally, for the gate insulator (GI), certain high-κ materials [22], such as aluminum oxide (Al 2 O 3 ) and hafnium oxide (HfO 2 ), have been deposited by atomic layer deposition (ALD) [23] with several advantages such as atomic-scaled thickness control, high film density, and superior step coverage and uniformity. Therefore, our previous study demonstrated that the integration of a HfO 2 GI and ultra-thin amorphous indium tungsten oxide (a-IWO) junctionless TFT can be achieved with promising electrical characteristics, such as high field-effect mobility (µ FE ), near ideal subthreshold swing (S.S.) (63 mV/dec), and large ON/OFF current ratios (I ON /I OFF ) (1.5 × 10 8 ) [24].…”

Recent progress and perspectives on atomic‐layer‐deposited semiconducting oxides for transistor applications

“…Although binary metal‐oxide channel systems offer simple composition and processing, securing the high mobility and controllability of V TH and excellent I ON/OFF ratio simultaneously can be difficult. To overcome this limit of binary oxides, multi‐component oxide materials such as ternary (indium gallium oxide [IGO], 55–57 indium zinc oxide [IZO], 58–60 and zinc tin oxide [ZTO] 61,62 ) and quaternary oxide (indium gallium zinc oxide [IGZO], 63–68 and indium zinc tin oxide [IZTO] 69,70 ) species have been examined as active‐material candidates for high‐performance TFTs. The design rationale should balance mobility enhancement and carrier suppression.…”

Selective Scan Driver for Low-Power Consumption Using Oxide Thin Film Transistors

“…Meanwhile, with the development of oxide thin film transistors (TFTs), low refresh rates have also become possible [2], [3]. Unlike low temperature polycrystalline silicon (LTPS) TFTs, oxide TFTs have an ultra-low leakage current characteristic [4]- [8]. It means pixel voltage is maintained for a very long time without refreshing.…”