A six‐mask TFT‐LCD process using copper‐gate metallurgy

Fryer, P. M.; Colgan, E. G.; Galligan, E.; Graham, William P.; Horton, R.; Hunt, D.; Jenkins, L. C.; John, R.; Koke, P.; Kuo, Yue; Latzko, K.; Libsch, F.; Lien, A.; Nywening, R.; Polastre, R.; Rothwell, Mary Beth; Wilson, John S.; Wisnieff, R.; Wright, S. L.

doi:10.1889/1.1985124

Cited by 14 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several parameterized components were used to express the subgap density of states (DOS), such as the acceptor-like exponential and Gaussian functions and the donor-like exponential and Gaussian functions. 21 In this work, we introduce an exponential function g exp (E) expressed by: [ 4 ] to describe the DOS near the conduction band, where N TA is the conduction band edge intercept energy, E is the state energy, E C is the conduction band edge, and W TA is the characteristic decay energy of the exponential distribution. The sub-gap DOS function g G (E) that Cu forms in IGZO film is modeled by: 5] where N GA and N GD are the densities at the peak of Gaussian distribution, E GA and E GD are the centers of the distribution, W GA and W GD are the characteristic decay energies of Gaussian distribution for the acceptor-like and donor-like states, respectively.…”

Section: Defects Induced By Coppermentioning

confidence: 99%

“…Many attempts have been made to incorporate Cu into the amorphous silicon TFT array fabrication. [3][4][5] The process implementation of using Cu as the source/drain (S/D) metal of a-IGZO TFT is also an interesting topic to study. However, most of the previous papers about a-IGZO TFT with the application of Cu emphasized on the contact resistance and the quality of the surface between Cu and a-IGZO.…”

mentioning

confidence: 99%

See 1 more Smart Citation

The Deterioration of a-IGZO TFTs Owing to the Copper Diffusion after the Process of the Source/Drain Metal Formation

Tai¹,

Chiu²,

Chou³

2012

J. Electrochem. Soc.

View full text Add to dashboard Cite

In this work, the influence of copper on amorphous type Indium-Gallium-Zinc-Oxide (a-IGZO) thin-film transistor's (TFTs) transfer curve is studied. The I D -V G curves of a-IGZO TFTs with source/drain in the structures of Cu/Ti and Ti/Al/Ti are compared. The results show that the copper greatly deteriorates the performance of the TFTs. The presence of the copper in the channel region of the device is verified by SIMS analysis. A Cu-dipping experiment is conducted by dipping devices into the solution of CuSO 4 to confirm the role of copper in the deterioration of the I D -V G curves. The hypothesis is also verified through ATLAS device simulator.Indium-Gallium-Zinc-Oxide (a-IGZO) thin-film transistors (TFTs) have attracted great attention for the impressive transparent and high carrier mobility characteristics. They can serve in switching pixel or peripheral circuit application for active-matrix liquid crystal displays (AMLCDs) in the next generation. 1, 2 With the increase of display size, resolution, and the operating frequency in television and 3D display, Cu is applied to replace Al for the reduction of resistance loading in the signal metal bus. Many attempts have been made to incorporate Cu into the amorphous silicon TFT array fabrication. [3][4][5] The process implementation of using Cu as the source/drain (S/D) metal of a-IGZO TFT is also an interesting topic to study. However, most of the previous papers about a-IGZO TFT with the application of Cu emphasized on the contact resistance and the quality of the surface between Cu and a-IGZO. 6-10 In the present work, the influence of Cu diffusion to the electrical properties of a-IGZO TFT is observed and studied. Device and ExperimentThe experimental work was based on the bottom-gate TFT devices of back-channel-etch (BCE) structure with symmetrical S/D fabricated on the glass substrate. Shaped Ti/Al/Ti (50/200/50 nm) gate electrodes were capped with 400-nm-thick SiNx gate dielectric, which was deposited by plasma enhanced chemical vapor deposition (PECVD) at 370 • C. The active layer of 60-nm-thick a-IGZO film was deposited by DC magnetron sputtering system using a target of In:Ga:Zn = 1:1:1 in atomic ratio with the O 2 /Ar ratio about 6%. For the S/D metals, both samples of Ti/Al/Ti (50/200/50 nm) and Cu/Ti (200/50 nm) were prepared by DC sputtering at room temperature. Then, the devices are capped with passivation at 280 • C as protection layer to avoid the disturbance of outside surrounding. After that, via holes and ITO were patterned and shaped for device measurement. The final annealing step was conducted at 280 • C for 1 hour in the oven. In this study, the electrical characteristics are measured by Agilent 4156-C system at 25 • C in dark under 1 atmosphere pressure. The threshold voltage (V T ) is defined by the gate voltage (V G ) when the size-normalized drain current I D reaches 10 −9 A. The subthreshold swing (S.S) and effective field mobility (μ) are extracted at drain voltage V D = 1V. Transfer CharacteristicsFigure 1a and 1b show the electrical ...

show abstract

Section: Defects Induced By Coppermentioning

confidence: 99%

mentioning

confidence: 99%

The Deterioration of a-IGZO TFTs Owing to the Copper Diffusion after the Process of the Source/Drain Metal Formation

Tai¹,

Chiu²,

Chou³

2012

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…Cu is now tested in many ways. [16][17][18][19] Ag is particularly promising because of its good contact property with n + a-Si and with the pixel electrode. Another advantage of Ag is its high-reflection electrode for reflective-type displays.…”

Section: Future Materials For Future Four-mask Processmentioning

confidence: 99%

Current manufacturing technologies for TFT‐LCDs

et al. 2001

View full text Add to dashboard Cite

Abstract— TFT‐LCD panels for notebook‐PC applications requires a thin and light form factor, low power consumption, and good display quality, whereas the desktop monitor has different requirements such as large panel size, wide viewing angle, high resolution, brightness, etc. However, for the fifth‐generation of mass production, current panel technologies have to improve in order to cope with these requirements. In this article, various approaches to the manufacturing technologies of next‐generation TFT‐LCDs are discussed.

show abstract

“…Annealing Cu Cr ( ) alloy at 400 C in O environment gives rise to the self-passivation of Cu by forming Cr O , which showed good adhesion to the substrate glass and good stability of Cu [8]. Second, an insertion of ITO layer between glass substrate and Cu gate shows a good adhesion to glass substrate [9]. Third, the self-encapsulated Cu, upon annealing of Cu/Mg alloy in O environment, shows an efficient passivation of Cu subjected to all plasma enhanced chemical vapor deposition (PECVD) processes [10], [11].…”

Section: Introductionmentioning

confidence: 99%

Copper gate hydrogenated amorphous silicon TFT with thin buffer layers

Lee

Cho

Choo

et al. 2002

IEEE Electron Device Lett.

View full text Add to dashboard Cite

We demonstrated a Cu gate hydrogenated amorphous silicon thin-film transistor (TFT) with buffer layers. We introduced an AlN/Cu/Al 2 O 3 multilayer for a gate of an a-Si : H TFT. The Al 2 O 3 improves the adhesion to glass substrate and AlN protect the Cu diffusion to the TFT and plasma damage to Cu during plasma enhanced chemical vapor deposition of silicon-nitride. An a-Si : H TFT with a Cu gate exhibited a field effect mobility of 1.18 cm 2 /Vs, a gate voltage swing of 0.87 V/dec., and a threshold voltage of 3.5 V.Index Terms-AMLCD, low resistivity, metal, thin-film transistor (TFT).

show abstract

A six‐mask TFT‐LCD process using copper‐gate metallurgy

Cited by 14 publications

References 0 publications

The Deterioration of a-IGZO TFTs Owing to the Copper Diffusion after the Process of the Source/Drain Metal Formation

The Deterioration of a-IGZO TFTs Owing to the Copper Diffusion after the Process of the Source/Drain Metal Formation

Current manufacturing technologies for TFT‐LCDs

Copper gate hydrogenated amorphous silicon TFT with thin buffer layers

Contact Info

Product

Resources

About