Channel Defect Analysis Method of a-IGZO TFTs on Polyimide for Flexible Displays

Kim, Hyojung; Jeon, Bohyeon; Park, Jong Woo; Kim, June-Hwan; Kim, Soonkon; Song, Minjun; Choi, Pil Cho; Park, Jung Min; Kim, Kihwan; Song, Jang‐Kun; Choi, Byoungdeog

doi:10.5573/jsts.2020.20.5.474

Cited by 5 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For bending experiments, TFT backplane on polyimide (PI) substrate was laminated on protective film (adhesive-coated polymer film) or sandwiched between two protective, which can establish the neutral plane close to TFT layer. 13 To evaluate mechanical durability of a flexible LTPS TFT backplane, a cyclic bending test was also performed at a bending radius (R). When a TFT on PI substrate is bent, stress is distributed inside TFT backplane.…”

Section: Methodsmentioning

confidence: 99%

Flexible TFT backplane development for extremely small bending radius with organic ILD and novel TFT structures

Kim,

Seol,

Lee

et al. 2024

J Soc Info Display

View full text Add to dashboard Cite

A new flexible low‐temperature polycrystalline silicon thin film transistors (LTPS TFTs) on PI substrate with organic ILD layer, island TFT, and TFT channel perpendicular to stress direction was proposed. AMOLED display panel manufactured with organic ILD did not show any visible degradation of panel image after outward rolling cycles of 200,000 at rolling radius of 4 mm or inward folding cycles of 200,000 at folding radius of 1 mm. Another novel structure of TFT with channel perpendicular to stress direction significantly reduced change of threshold voltage of −0.03 V compared with change of threshold voltage of −0.6 V for TFT with channel parallel to stress direction for reliability test of high drain current (HDC) after 100,000 outward‐bending cycles at bending radius of 3 mm. After inward‐bending cycles of 200,000 at bending radius of 1 mm, reliability test results for TFT device with organic ILD layer showed that change of on‐current is 10.07% for hot carrier instability (HCI) test, change of threshold voltage −0.31 V for negative bias thermal instability (NBTI) test, change of threshold voltage −0.24 V for hysteresis test, and breakdown voltage of gate insulator 7.73 MV/cm, respectively, and these performances are similar to those of TFT device with inorganic ILD (SiNx).

show abstract

Section: Methodsmentioning

confidence: 99%

Flexible TFT backplane development for extremely small bending radius with organic ILD and novel TFT structures

Kim,

Seol,

Lee

et al. 2024

J Soc Info Display

View full text Add to dashboard Cite

show abstract

“…Since the glass transition temperature of PI is less than 500 °C, a low-temperature process is essential to the fabrication of PI-substrate-based TFTs 7 . As such, low-temperature polycrystalline silicon (LTPS) TFTs with good mobility or amorphous indium gallium zinc oxide (a-IGZO) TFTs with a good on/off ratio are used 8 – 11 . However, the occurrence of specific threshold voltage (V th ) behavior during the reliability evaluation of TFTs fabricated on PI substrates was recently reported 12 , 13 .…”

Section: Introductionmentioning

confidence: 99%

Effects of polyimide curing on image sticking behaviors of flexible displays

Kim

Park

Bak

et al. 2021

Sci Rep

View full text Add to dashboard Cite

Flexible displays on a polyimide (PI) substrate are widely regarded as a promising next-generation display technology due to their versatility in various applications. Among other bendable materials used as display panel substrates, PI is especially suitable for flexible displays for its high glass transition temperature and low coefficient of thermal expansion. PI cured under various temperatures (260 °C, 360 °C, and 460 °C) was implemented in metal–insulator–metal (MIM) capacitors, amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFT), and actual display panels to analyze device stability and panel product characteristics. Through electrical analysis of the MIM capacitor, it was confirmed that the charging effect in the PI substrates intensified as the PI curing temperature increased. The threshold voltage shift (ΔVth) of the samples was found to increase with rising curing temperature under negative bias temperature stress (NBTS) due to the charging effect. Our analyses also show that increasing ΔVth exacerbates the image sticking phenomenon observed in display panels. These findings ultimately present a direct correlation between the curing temperature of polyimide substrates and the panel image sticking phenomenon, which could provide an insight into the improvement of future PI-substrate-based displays.

show abstract

Charging Compensation Layer on Polyimide for Enhanced Device Stability in Flexible Technology

Kim

Park

et al. 2021

Electron. Mater. Lett.

View full text Add to dashboard Cite

Channel Defect Analysis Method of a-IGZO TFTs on Polyimide for Flexible Displays

Cited by 5 publications

References 0 publications

Flexible TFT backplane development for extremely small bending radius with organic ILD and novel TFT structures

Flexible TFT backplane development for extremely small bending radius with organic ILD and novel TFT structures

Effects of polyimide curing on image sticking behaviors of flexible displays

Charging Compensation Layer on Polyimide for Enhanced Device Stability in Flexible Technology

Contact Info

Product

Resources

About