Employ Present Five Masks Amorphous Silicon Thin-Film Transistor Design and Process Flow to Realize 5-in. InGaZnO Active-Matrix Liquid Crystal Display with Improved Stress Stability

Abstract

The present five masks bottom gate and staggered amorphous silicon (a-Si) thin-film transistor (TFT) process flow is not suitable for indium–gallium–zinc-oxide (IGZO) TFT because of its vulnerability to post etching process during the source/drain pattern. Bottom gate and coplanar IGZO TFTs were made feasible through the reverse of second (channel layer) and third (source/drain electrodes) masks process flow to avoid etching damage problem. Besides, the post IGZO nitrous oxygen (N2O) plasma treatment was employed to improve the stress instability. On the basis of secondary ion mass spectrometry (SIMS) and X-ray spectroscopy (XPS) results, it is believed that the post N2O plasma treatment passivates the interface states and converts the inhomogeneous and low quality IGZO to the homogeneous and high quality IGZO. In the end, a 5-in. IGZO active-matrix liquid crystal display was demonstrated via five masks bottom gate and coplanar TFT configuration.

Depth-Profiling Study on Amorphous Indium–Gallium–Zinc Oxide Thin-Film Transistors by X-ray Photoelectron Spectroscopy

“…[11][12][13] It was also reported that dry etching of S/D electrodes results in a conductive a-IGZO active layer, and a N 2 O plasma treatment before the deposition of a passivation layer can recover the original conductive characteristics of the back-channel surface. 14,15) Ti and Mo have been widely used as S/D electrode materials in a-IGZO TFTs because of their process compatibility with conventional Si-based TFTs. However, to date, there have been few reports on the chemical states at the interfaces and on surfaces composed of these materials.…”

Low-Operating-Voltage Solution-Processed InZnO Thin-Film Transistors Using High-k SrTa2O6

“…However, the mobility is not sufficiently high for application in flat panel displays. 3) The obtained low V th and high on/off current ratio could be easily understood using eq. ( 1) because of the use of a high-k material.…”

“…Zinc oxide (ZnO)-based thin-film transistors (TFTs) have attracted significant attention owing to their high performance and optical transparency in the visible region. [1][2][3][4][5][6][7][8][9][10] However, despite their superior performance, most fabrication methods for the production of ZnO-based thin films involve vacuum processes, such as sputtering, pulsed laser deposition, and plasma-enhanced chemical vapor deposition. [1][2][3][4][5][6][7][8][9][10] Vacuum deposition methods require expensive equipment and result in high manufacturing costs.…”

“…[1][2][3][4][5][6][7][8][9][10] However, despite their superior performance, most fabrication methods for the production of ZnO-based thin films involve vacuum processes, such as sputtering, pulsed laser deposition, and plasma-enhanced chemical vapor deposition. [1][2][3][4][5][6][7][8][9][10] Vacuum deposition methods require expensive equipment and result in high manufacturing costs. In contrast, solution-process deposition methods could offer many advantages, such as low cost, simplicity, high throughput, and accurate control of composition for multicomponent thin films.…”

Influence of white light illumination on the performance of a-IGZO thin film transistor under positive gate-bias stress

“…[1] Due to their superior properties, such as high channel mobilities, low processing temperatures, low off-state leakages, and high optical transparencies, a-IGZO TFTs are considered as the backplane technology for next generation active matrix liquid crystal displays (AMLCDs) and organic light-emitting diode displays (OLEDs). [2][3][4][5][6] In spite of their promising performance, reliability remains a critical issue for a-IGZO TFT technology. These devices could suffer serious performance shift or degradation under bias stress, under illumination, and under environmental aging.…”