Improvement in the bias stability of amorphous indium gallium zinc oxide thin-film transistors using an O2 plasma-treated insulator

Moon, Yeon-Keon; Lee, Sih; Kim, Woong-Sun; Kang, Byung-Woo; Jeong, Changwook; Lee, Dong‐Hoon; Park, Jong-Wan

doi:10.1063/1.3167816

Cited by 99 publications

(52 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most serious problem is the long-term stability of TFT characteristics, but recent works have achieved threshold voltage shifts of less than 2 V and even smaller than 1 V [74][75][76]. Our group has reported that thermal annealing under a wet O 2 atmosphere stabilizes the chemical bonds, leading to improved and stable TFT characteristics, and we have found that the true origin of the stability originates from the formation of acceptor-type electron traps formed under constant bias stress [77].…”

Section: Summary: Present and Future Issuesmentioning

confidence: 85%

Material characteristics and applications of transparent amorphous oxide semiconductors

2010

View full text Add to dashboard Cite

A morphous semiconductors have created a new area of electronics known as 'giant microelectronics' typifi ed by devices such as solar cells and active-matrix (AM) fl at-panel displays. Single-crystalline semiconductor technology, typifi ed by crystal silicon electronics, is unsuitable for such applications, whereas amorphous or polycrystalline fi lms can be easily formed over large areas of greater than 1 m 2 at low temperature (e.g. < 400 °C) on both glass and plastic substrates, facilitating these new applications. Due to carrier scattering and trapping at defects on grain boundaries in polycrystalline materials (the grain boundary problem), hydrogenated amorphous silicon (a-Si:H) has been used more widely than polycrystalline silicon (p-Si) for practical large-size applications. However, the critical obstacles to be overcome to realize a-Si:H in future applications are low mobility (< 1 cm 2 /V s) and instability against electric stress and photo-illumination.In late 2004, we reported that an amorphous oxide semiconductor (AOS) with the composition a-InGaZnO 4 (a-IGZO) can be applied in the fabrication of fl exible, transparent thin-fi lm transistors (TFTs) having much improved performance compared to conventional TFTs based on a-Si:H and organic materials [1]. AOS materials have superior characteristics to conventional semiconductors, and therefore AOS TFT technology has grown very rapidly toward the realization of TFT backplanes for next-generation flat-panel displays. As summarized in Figure 1, a variety of prototype AM displays have been demonstrated by several companies within the last fi ve years since the fi rst report of AOS TFTs. Herein, we review the unique characteristics of AOS materials in relation to their TFT characteristics, and discuss why AOSs have such attractive electrical properties related to the electronic structures specifi c to transparent oxides. Active-matrix displays and circuits based on AOS TFT arraysTh e fi rst AOS-TFT was reported in late 2004 (see Figure 1). Just one year later, Toppan Printing quickly followed with the fi rst AM display based on AOS as a fl exible black-and-white electronic paper (e-paper) using a-IGZO TFTs

show abstract

Section: Summary: Present and Future Issuesmentioning

confidence: 85%

Material characteristics and applications of transparent amorphous oxide semiconductors

2010

View full text Add to dashboard Cite

show abstract

“…Especially, a-IGZO TFTs have been recognized as a very promising alternative to display backplanes of active matrix organic light emitting diodes (AMOLEDs) and thin-film transistor liquid crystal displays (TFT-LCDs) [1,2]. For practical applications, it was important to have the bias independent reliability and a number of groups have studied the stability of a-IGZO TFTs [3][4][5][6][7]. Particularly, the hump characteristics were considered as one of the critical issues during the operation in TFT displays affecting pixel brightness [8].…”

Section: Introductionmentioning

confidence: 99%

Anomalous Stress-Induced Hump Effects in Amorphous Indium Gallium Zinc Oxide TFTs

Kim¹,

Jeong²,

Yun³

et al. 2012

Transactions on Electrical and Electronic Materials

View full text Add to dashboard Cite

In this paper, we investigated the anomalous hump in the bottom gate staggered a-IGZO TFTs. During the positive bias stress, a positive threshold voltage shift was observed in the transfer curve and an anomalous hump occurred as the stress time increased. The hump became more serious in higher gate bias stress while it was not observed under the negative bias stress. The analysis of constant gate bias stress indicated that the anomalous hump was influenced by the migration of positively charged mobile interstitial zinc ion towards the top side of the a-IGZO channel layer.

show abstract

“…[1][2][3][4][5] However, there are still many issues related to the control of threshold voltage and bias-induced degradation. [6][7][8][9][10][11] Therefore, there have been many studies on improving AOS TFT stability such as high-pressure oxygen annealing, 12 annealing in hydrogen environment, 13 O 2 plasma treatment, 14 suitable passivation materials, 15 long channel TFT 16 and long-time annealing, etc. 17 Especially, the performance of a-IGZO TFT depends on channel length, and the TFTs with channel length less than 2 µm exhibit mostly depletion mode behavior.…”

mentioning

confidence: 99%

Control of O-H bonds at a-IGZO/SiO2 interface by long time thermal annealing for highly stable oxide TFT

Jeon

Lee

et al. 2017

AIP Advances

View full text Add to dashboard Cite

We report two-step annealing, high temperature and sequent low temperature, for amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) to improve its stability and device performance. The annealing is carried out at 300 oC in N2 ambient for 1 h (1st step annealing) and then at 250 oC in vacuum for 10 h (2nd step annealing). It is found that the threshold voltage (VTH) changes from 0.4 V to -2.0 V by the 1st step annealing and to +0.6 V by 2nd step annealing. The mobility changes from 18 cm2V-1s-1 to 25 cm2V-1s-1 by 1st step and decreases to 20 cm2V-1s-1 by 2nd step annealing. The VTH shift by positive bias temperature stress (PBTS) is 3.7 V for the as-prepared TFT, and 1.7 V for the 1st step annealed TFT, and 1.3 V for the 2nd step annealed TFT. The XPS (X-ray photoelectron spectroscopy) depth analysis indicates that the reduction in O-H bonds at the top interface (SiO2/a-IGZO) by 2nd step annealing appears, which is related to the positive VTH shift and smaller VTH shift by PBTS.

show abstract

Improvement in the bias stability of amorphous indium gallium zinc oxide thin-film transistors using an O2 plasma-treated insulator

Cited by 99 publications

References 6 publications

Material characteristics and applications of transparent amorphous oxide semiconductors

Material characteristics and applications of transparent amorphous oxide semiconductors

Anomalous Stress-Induced Hump Effects in Amorphous Indium Gallium Zinc Oxide TFTs

Control of O-H bonds at a-IGZO/SiO2 interface by long time thermal annealing for highly stable oxide TFT

Contact Info

Product

Resources

About