Self-Assembled Monolayers (SAMs)/Al₂O₃ Double Layer Passivated InSnZnO Thin-Film Transistor

Abstract

We fabricated high-performance InSnZnO (ITZO) thin-film transistors (TFTs) with self-assembled monolayers (SAMs)/Al2O3 double passivation layers (PVLs). The presented SAMs/Al2O3 double passivation leads to high-performance ITZO TFTs with a steep subthreshold slope (∼85 mV/dec), a low threshold voltage (∼0.9 V), high mobility (∼19.8 cm 2 V-1 s-1), and high on-off current ratio (∼8.7 ×10 9). Moreover, compared to devices with Al2O3 PVL, ITZO TFTs with SAMs/Al2O3 double PVLs show better stability in ambient air with a relative humidity of 60% under positive bias stress (PBS) and negative bias stress (NBS). This enhanced stability is attributed to the presence of a highquality SAM/Al2O3 dual PVL, which not only inhibits Vo-related trap sites and reduces overall trap density, but also protects the back-channel from environmental influences.

Color-Filter-Free Three-Layer-Stacked Image Sensor Using Blue/Green-Selective Organic Photoconductive Films with Thin-Film Transistor Circuits on CMOS Image Sensors

“…In this structure, the TFT circuit is not directly stacked on an OPF to avoid the difficulties in improving the sensor resolution described above. In addition, indium–tin–zinc–oxide (ITZO) was used as a high-mobility active channel material for the TFTs − to accommodate a smaller pixel size of 20 μm and a higher number of pixels of 320 × 240 (QVGA). The color video imaging operation of the sensor was confirmed, and spectral crosstalk lower than those of the previous three-layer-stacked sensors mentioned in refs and was achieved, especially in the R-light region, through the integration of the CIS and two color-selective OPFs.…”

Low Cost, Al2O3 and ZrAlOx Stack Passivation by Spray Pyrolysis for Highly Stable Amorphous InGaZnO Thin‐Film Transistors

“…To understand the reduction of µ FE , the charge trap density (N t ) is calculated from the SS. [34,42,45] The SS of MO-TFT has a close relationship with N t , including the defect states in the bulk (N bulk ) of a channel layer and the interface of GI and semiconductor layers (N it ). [34,42,45] The obtained N t of the a-IGZO TFTs with no passivation, ZAO, Al 2 O 3 , ZAO/Al 2 O 3 , and Al 2 O 3 /ZAO PA layers are 1.32 × 10 12 , 1.20 × 10 12 , 8.96 × 10 11 , 1.08 × 10 12 , and 9.38 × 10 11 cm −2 eV −1 , respectively.…”

“…[18][19][20][21]27,[38][39][40][41] However, very few of them such as Y 2 O 3 , HfO 2 , and aluminium oxide (Al 2 O 3 ) are studied as a PA layer for MO-TFTs. [27,32,34,42,43] Jewel et al investigate the effect on zinc oxide (ZnO) TFTs with Y 2 O 3 PA layer by spray pyrolysis. [27] Though the electrical stabilities of ZnO TFTs are improved, the Y diffuses into the ZnO channel layer, resulting in the reduction of carrier mobility.…”

“…[46][47][48] On the other hand, Zhong et al study the stability of Al 2 O 3 passivated indiumtin-zinc-oxide TFTs using the spin coating, exhibiting ΔV TH of 3.6 V during positive bias stress (PBS). [42] Ding et al report that the In 2 O 3 TFTs with spin-coated Al 2 O 3 PA layer exhibit moderate stability (ΔV TH = 0.116 V for 2000 s) under PBS in ambient conditions without examining the environmental stability. [43] Note that the H 2 O is reactive with Al 2 O 3 under the air environment in humid conditions.…”

“…[43] Note that the H 2 O is reactive with Al 2 O 3 under the air environment in humid conditions. [42,45,49] Therefore, the stack PA layer could be a favorable approach to obtain highly stable MO-TFTs against thermal and environmental stabilities. [42,45] Whereas, the bottom PA layer should make a clean interface with the channel semiconductor without diffusing into it and the top PA layer should act as a good thermal and environmental barrier.…”