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![a) The cross‐sectional view of top gate poly‐Si TFT in ESD reliability test. b) The forward/reverse transfer curves of ploy‐Si TFT before/after 40 V ESD stress. c) The poly‐Si TFT stressed at 60 V (partial failure) and d) 70 V (complete failure) ESD voltage. Reproduced with permission.[⁹¹] Copyright 2012, John Wiley and Sons.](publication/357404525/figure/fig5/AS:11431281179403077@1691182410447/a-The-cross-sectional-view-of-top-gate-poly-Si-TFT-in-ESD-reliability-test-b-The.png)
a) The cross‐sectional view of top gate poly‐Si TFT in ESD reliability test. b) The forward/reverse transfer curves of ploy‐Si TFT before/after 40 V ESD stress. c) The poly‐Si TFT stressed at 60 V (partial failure) and d) 70 V (complete failure) ESD voltage. Reproduced with permission.[⁹¹] Copyright 2012, John Wiley and Sons.
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Electrostatic discharge (ESD) is one of the most prevalent threats to the reliability of electronic components, which can result in a very high current passing through the device or microchip within a very short period of time, and cause serious irreversible damage. Thin film transistors (TFTs) are widely used in flat panel display, sensor, memrist...
Citations
... As sensor complexity increases, the manufacturing process must achieve higher precision, which also raises the risk of internal component failures. For example, on-chip integration of edgeemitting lasers with nanometer node transistor technologies can result in complex failure mechanisms due to thermal overstress [3], electrostatic discharge [4], fabrication variabilities [5], aging [6], etc. Likewise, in emerging multi-pixel LiDAR and RADAR sensors [7], interference from nearby pixels can result in cross-talk, thus corrupting their sensor readings. ...
Electrostatic discharge (ESD) is one of the common threats to the reliability of electronic components, and device-level ESD protection is the last line of defense for the stable operation of electronic products. The development of flexible electronics technology has growing requirements for thin-film transistors (TFTs) reliability. However, there is a scarcity of pertinent research on the ESD stress reliability of flexible TFTs subjected to repeated bending. In this article, the electrical properties and ESD stress reliability of flexible TFTs are studied. Polymer surface modifications are used to improve device
I
–
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characteristics, electrical stability and enhance devices’ ESD robustness. These enhancements are associated with the augmentation of semiconductor film growth, the modulation of defect state density at dielectric/semiconductor interfaces, the protection of breakdown paths, and the mitigation of bending stress through buffering. This research work provides the theoretical basis and design ideas for the fabrication of flexible TFTs with high ESD stress reliability.
In the actual HBM test, it is found that the ESD test results of various power MOSFET devices show asymmetry between forward and reverse withstand voltages, while the ESD process does not distinguish between positive and negative directions. Large differences in forward and reverse withstand voltages are unacceptable for power MOSFETs or as ESD protection devices. The problem of its causing device failure is particularly pronounced. In this paper, by establishing the analytical model of gate to source capacitance of SGT-MOSFET, VUMOSFET and VDMOS under the forward and reverse voltages, we comparatively analyze the reasons for the asymmetry of the forward and reverse withstand voltages and their different ratios of the three kinds of power MOSFET, which provides a theoretical basis for the testing of the device's ESD and the analysis of its reliability. It is found that the ESD forward and reverse withstand voltage asymmetry phenomenon of different power MOSFET structures is related to the variation of gate to source capacitance caused by the reverse-type layer. When a forward voltage is applied between the gate and source, the device gate to source capacitance consists of the oxide layer capacitance around the gate in parallel; when a reverse voltage is applied, the gate to source capacitance consists of the virtual gate to drain capacitance in series with the inverse layer capacitance and then in parallel with the other oxide layer capacitance around the gate. This results in a decrease in the gate to source capacitance at the reverse voltage, making the device reverse withstand voltage greater than the forward withstand voltage. The difference in the ratio of ESD reverse withstand voltage to forward withstand voltage for different devices is related to the change in the capacitance of the inverse layer in the gate to source capacitor under reverse voltage caused by the difference in device structure.
Electrostatic damage has been shown to be a common phenomenon in display applications especially in flexible organic light-emitting diodes (OLEDs). Herein, to analyze the damage formation process and the internal physical mechanism, a bottom gate-like effects model based on the accumulation of negative charges under a thin film transistor (TFT) channel was proposed. The results after electro-static discharge (ESD) test substantiated that the threshold voltage (
$\text{V}_{\text {th}}{)}$
was positively shifted and the subthreshold swing (SS) was increased, which caused the luminance variation of flexible OLEDs. Furthermore, these changes can also be reproduced by applying a voltage under the samples, which is an analogy to the bottom gate-like effects. In order to alleviate the electrostatic damage influences, hydrogen plasma was adopted as an interface modification method to enhance the stability of TFT under electro-static discharge conditions. The research opens the possibility of considering more relationship between the display performance and the microscopic charge behaviors for their actual applications.
The electrical stability of perovskite solar cells (PSCs) will play an essential role in their commercialization because field‐installed PSCs frequently operate under non‐ideal voltages. Particularly, an instantaneous extremely high voltage (IEHVs) from electro‐static discharge will be applied to PSCs due to friction in roll‐to‐roll processes. In addition, lightning strikes and surges from grids are plausible sources of IEHVs to field‐installed PSCs. Hence, the effect of IEHVs on PSCs is systematically investigated and a robust device structure is suggested. An IEHV severely deteriorates PSCs by destroying their diode characteristics. Physical and chemical damage from IEHVs to the interface between the perovskite film and buffer layers causes increased recombination losses and series resistance. To reinforce the heterointerface, a well‐known surface defect passivation method is adopted, adding excessive PbI2 to perovskite films. The excessive PbI2, mainly located at the interface, successfully protects PSCs from IEHV. Moreover, inserting well‐established defect passivation layers, C60, and phenethylammonium iodide into the interface of a perovskite film improves the device's stability against IEHV. Therefore, interface defect passivation is viable for stable PSCs against abnormal electrical stress. It is believed that this study will provide fundamental insights for designing electrically reliable PSCs, which is crucial for grid‐connected, field‐installed energy generation sources.
In this study, the failure phenomenon of high-pin-count BGA device ESD test by stressing NC pins was tested and analyzed since NC pin withstands HBM pulse as the signal pin during practical application and experiences new failure mode and mechanism. The effects of NC pins ESD test on the reliability of integrated circuits and the failure mechanism were subsequently investigated via experimental methods. Results show that ESD level identification tests with stressing NC pins exhibit abnormal failure mode compared with typical ESD failure. Meanwhile, a distributed capacitance method (DCM) is proposed to explain the phenomenon and failure mechanism, which is affected by the packaging materials and particular spacing distance between adjacent pins. When the HBM ESD pulse is applied on the NC pin, the signal pin adjacent to NC pin regularly fails due to the existence of distributed capacitance CM + CM(air) and air arc breakdown. The verification experimental tests of failure analysis reveal that the monitored huge and extremely fast current forms through the distributed capacitance coupling and air arc mode.
Oxide thin film transistors (TFTs) attract much attention in fields of advanced displays and low‐cost integrated circuits (ICs). In this work, hafnium doped InSnO (Hf‐ITO) thin films are deposited by co‐sputtering process, and are applied as the active layer to TFTs. Notably, the Hf‐ITO TFTs exhibit excellent device performance, preferable uniformity, and good gate‐bias‐stress stability. Major electrical parameters of the Hf‐ITO TFTs include a field‐effect mobility (μFE) of 7.46 cm2V−1s−1, a turn‐on voltage (VON) of 1.10 V, a sub‐threshold swing (SS) of 341.18 mV/decade, and an on/off state current ratio (ION/IOFF) over 105. Our work proposes a novel method for developing high‐mobility semiconductor oxide films and oxide TFTs.
