Hydrogen Diffusion and Threshold Voltage Shifts in Top-Gate Amorphous InGaZnO Thin-Film Transistors

Chen, Hong-Chih; Chen, Jianjie; Zhou, Kuan‐Ju; Chen, Guan-Fu; Kuo, Chang-Hung; Shih, Yu‐Shan; Su, Wan-Ching; Yang, Ching‐Chieh; Huang, Hui‐Chun; Shih, Chih‐Cheng; Lai, Wei-Chih; Chang, Ting‐Chang

doi:10.1109/ted.2020.2998101

Cited by 29 publications

(19 citation statements)

References 37 publications

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“…This is a general behavior for coplanar a‐IGZO TFTs with SiO 2 passivation. [ 15,16,31,32 ] Chen et al reported that hydrogen diffuses into the intrinsic a‐IGZO for the coplanar oxide TFTs. [ 15,31 ] Therefore, the TFT becomes more depletion mode by decreasing L .…”

Section: Resultsmentioning

confidence: 99%

“…[ 15,16,31,32 ] Chen et al reported that hydrogen diffuses into the intrinsic a‐IGZO for the coplanar oxide TFTs. [ 15,31 ] Therefore, the TFT becomes more depletion mode by decreasing L . [ 13–15 ] Therefore, the TFT has a large negative shift of V th from −0.6 V ( L = 10 μm) to −11.4 V ( L = 1.5 μm), as shown in Figure 2a.…”

Section: Resultsmentioning

confidence: 99%

“…[ 15,31 ] Therefore, the TFT becomes more depletion mode by decreasing L . [ 13–15 ] Therefore, the TFT has a large negative shift of V th from −0.6 V ( L = 10 μm) to −11.4 V ( L = 1.5 μm), as shown in Figure 2a. However, the TFTs with ZAO interlayer exhibit stable V th dependence with decreasing L .…”

Section: Resultsmentioning

confidence: 99%

“…This behavior appears to be related to shortening the effective L by unintentional doping due to the lateral diffusion of donor‐like defects such as oxygen vacancy and/or hydrogen. [ 13–16 ]…”

Section: Introductionmentioning

confidence: 99%

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Improvement of Thermal and Environmental Stabilities of Short Channel Coplanar Amorphous InGaZnO Thin‐Film Transistors by Introducing Amorphous ZrAlO_x Interlayer

Lee

Islam

et al. 2021

Adv Eng Mater

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The short channel coplanar amorphous indium gallium zinc oxide (a‐IGZO) thin‐film transistor (TFT) is reported by introducing a ZrAlO x (ZAO) interlayer deposited by spray pyrolysis at the substrate temperature of 350 °C. The atomic ratio (at. %) of In:Ga:Zn:O is 1:2.5:1.2:5.2 in the a‐IGZO film deposited by sputtering. The a‐IGZO TFT with ZAO layer with 0.87 μm channel length exhibits the field‐effect mobility of 6.44 cm2 V−1 s−1, the threshold voltage of −2.16 V, and on/off current ratio of 7.6 × 107. It is found from the X‐ray photoelectron spectroscopy depth profile and high‐resolution transmission electron microscope analysis that some Zr atoms diffuse into the a‐IGZO underlayer. The formation of ZrO bonds on a‐IGZO surface region reduces the carrier concentration in the a‐IGZO TFT offset region, between source/drain contact and the channel, and blocks the carrier diffusion into the channel. This reduces the field‐effect mobility of 10 μm channel length TFT from 21.86 to 14.01 cm2 V−1 s−1, but the ZAO layer protects the a‐IGZO from the diffusion of H2O and O2. As a result, 0.87 μm TFT shows high on/off current ratio and stable under 85 °C and 85% relative humidity test for 2 days.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improvement of Thermal and Environmental Stabilities of Short Channel Coplanar Amorphous InGaZnO Thin‐Film Transistors by Introducing Amorphous ZrAlO_x Interlayer

Lee

Islam

et al. 2021

Adv Eng Mater

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“…Besides the formation of H i and H O , a part of H + can also continue to diffuse into the backchannel of ITZO TFTs under E y . The H + aggregation at the backchannel would lower down the source/drain barriers [ 33,72,73 ] and thus further make the device easier to be turned on. Additionally, with the assistance of large E y induced by PBS, the MO bonds may be broken down and additional V O s may be introduced, bringing the increase of the free carrier concentration and further making the device turned on early.…”

Section: Mechanism Discussionmentioning

confidence: 99%

Effect of Moisture Exchange Caused by Low‐Temperature Annealing on Device Characteristics and Instability in InSnZnO Thin‐Film Transistors

Chen

Zhang

Deng

et al. 2022

Adv Materials Inter

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Thin‐film transistors (TFTs) in practical operations are inevitably impacted by moisture and temperature. An investigation on the joint effect of environmental moisture and working temperature on device characteristics and instability is becoming necessary. However, few related studies have been performed. In this work, a low‐temperature (LT) annealing in air is proposed to simulate the working conditions of TFTs in display applications. The effect of moisture exchange caused by LT annealing on device characteristics and instability of InSnZnO (ITZO) TFTs is systematically investigated. Combined with X‐ray photoelectron spectroscopy analysis, TCAD design simulation, and the measurement of relative humidity (RH) change on the device surface, a model considering water diffusion and water ionization is proposed. The negative shift of the transfer curve is attributed to the extra electrons released from the water ionization and the positive‐bias‐stress‐induced instability is mainly attributed to the generation of interstitial/substitutional hydrogens and aggregation of hydrogen ions at the backchannel. The temperature and the RH on the device surface jointly determine the moisture diffusion direction. Furthermore, the model is verified by an LT vacuum annealing. The results and the model will be beneficial for the further reliable design of ITZO TFTs in commercial applications.

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One Micrometer Channel Length, Coplanar Polycrystalline InGaO Thin Film Transistors Exhibiting 85 cm² V⁻¹ s⁻¹ Mobility and Excellent Bias Stabilities by Using Offset Engineering

Rabbi,

Arnob,

Nahar

et al. 2024

Adv Funct Materials

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The effect of N+ resistivity in the offset region, for ≈1 µm channel length coplanar, polycrystalline InGaO (PC‐IGO) thin‐film transistors (TFTs) is studied. The room temperature deposited amorphous IGO is solid phase crystallized at 450 °C. The PC‐IGO TFT exhibits a maximum effective field‐effect mobility (µFE) of ≈86.69 cm2 V−1 s−1, a threshold voltage of ≈1.5 V, and a subthreshold swing of ≈300 mV decade−1, with remarkable stability under bias and temperature stress. The offset length (Loff) is varied from 1 to 3 µm and their electrical performances are analyzed. Upon increasing the Loff from 1 to 3 µm, the on current (Ion) and the µFE drops from 50.31 to 17.72 µA and 85.40 to 67.64 cm2 V−1 s−1, respectively, which can be attributed to a greater voltage drop in the Loff, resulting in the reduction of effective VDS applied to the channel. Technology computer‐aided design simulations shows that at the sheet resistance of 14.5 Ω sq−1. in the N+ offset region, the Ion dependency disappears with the change in Loff, which is attributed to the negligible voltage drop. These results provide valuable insight into optimizing N+ doping, for high‐performance, short‐channel coplanar oxide TFTs.

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Hydrogen Diffusion and Threshold Voltage Shifts in Top-Gate Amorphous InGaZnO Thin-Film Transistors

Cited by 29 publications

References 37 publications

Improvement of Thermal and Environmental Stabilities of Short Channel Coplanar Amorphous InGaZnO Thin‐Film Transistors by Introducing Amorphous ZrAlO_x Interlayer

Improvement of Thermal and Environmental Stabilities of Short Channel Coplanar Amorphous InGaZnO Thin‐Film Transistors by Introducing Amorphous ZrAlO_x Interlayer

Effect of Moisture Exchange Caused by Low‐Temperature Annealing on Device Characteristics and Instability in InSnZnO Thin‐Film Transistors

One Micrometer Channel Length, Coplanar Polycrystalline InGaO Thin Film Transistors Exhibiting 85 cm² V⁻¹ s⁻¹ Mobility and Excellent Bias Stabilities by Using Offset Engineering

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Hydrogen Diffusion and Threshold Voltage Shifts in Top-Gate Amorphous InGaZnO Thin-Film Transistors

Cited by 29 publications

References 37 publications

Improvement of Thermal and Environmental Stabilities of Short Channel Coplanar Amorphous InGaZnO Thin‐Film Transistors by Introducing Amorphous ZrAlOx Interlayer

Improvement of Thermal and Environmental Stabilities of Short Channel Coplanar Amorphous InGaZnO Thin‐Film Transistors by Introducing Amorphous ZrAlOx Interlayer

Effect of Moisture Exchange Caused by Low‐Temperature Annealing on Device Characteristics and Instability in InSnZnO Thin‐Film Transistors

One Micrometer Channel Length, Coplanar Polycrystalline InGaO Thin Film Transistors Exhibiting 85 cm2 V−1 s−1 Mobility and Excellent Bias Stabilities by Using Offset Engineering

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Product

Resources

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Improvement of Thermal and Environmental Stabilities of Short Channel Coplanar Amorphous InGaZnO Thin‐Film Transistors by Introducing Amorphous ZrAlO_x Interlayer

Improvement of Thermal and Environmental Stabilities of Short Channel Coplanar Amorphous InGaZnO Thin‐Film Transistors by Introducing Amorphous ZrAlO_x Interlayer

One Micrometer Channel Length, Coplanar Polycrystalline InGaO Thin Film Transistors Exhibiting 85 cm² V⁻¹ s⁻¹ Mobility and Excellent Bias Stabilities by Using Offset Engineering