Critical Technologies for Poly-Si TFT in High Resolution AM-LCD

1997 ◽  
Vol 471 ◽  
Author(s):  
I-Wei Wu

ABSTRACTPolycrystalline silicon (p-Si) TFT offers higher aperture ratio with integrated driver circuits compared to the conventional a-Si TFT in AM-LCD application. The advantages of the p-Si TFT as the pixel switching element will be more pronounced for AM-LCDs with large number of scan lines and/or high pixel density. This paper reviews challenges and issues associated with the technology of p-Si TFT, particularly in active silicon layer deposition, solid phase and laser crystallization, hydrogenation, leakage current, performance of different device architectures and reliability. Critical issues affecting the p-Si TFT AMLCD pixel design are analyzed, including: lithographic resolution and overlay accuracy, pixel density and aspect ratio, display format, storage to LC capacitance ratio, and gate dielectric thickness. Predictions on the regimes of dominance for different flat-panel technologies by advantages in performance and-or cost with respect to panel size and pixel density will be presented.

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Kuninori Kitahara ◽  
Toshitomo Ishii ◽  
Junki Suzuki ◽  
Takuro Bessyo ◽  
Naoki Watanabe

Raman microscopy was applied to characterize polycrystalline silicon (poly-Si) on glass substrates for application as thin-film transistors (TFTs) integrated on electronic display panels. This study examines the crystallographic defects and stress in poly-Si films grown by industrial techniques: solid phase crystallization and excimer laser crystallization (ELC). To distinguish the effects of defects and stress on the optical-phonon mode of the Si–Si bond, a semiempirical analysis was performed. The analysis was compared with defect images obtained through electron microscopy and atomic force microscopy. It was found that the Raman intensity for the ELC film is remarkably enhanced by the hillocks and ridges located around grain boundaries, which indicates that Raman spectra mainly reflect the situation around grain boundaries. A combination of the hydrogenation of films and the observation of the Si-hydrogen local-vibration mode is useful to support the analysis on the defects. Raman microscopy is also effective for detecting the plasma-induced damage suffered during device processing and characterizing the performance of Si layer in TFTs.


1997 ◽  
Vol 472 ◽  
Author(s):  
H.-S. Choi ◽  
C.-M. Park ◽  
J.-H. Jeon ◽  
B.-H. Min ◽  
M.-K. Han

ABSTRACTThe effects of nitrogen-radical treated amorphous silicon (a-Si) films on laser-crystallization behavior have been studied for the improvement of the grain-growth and the surface roughness. The radical treatments were performed by the rf (13.56 MHz) plasma-enhanced-chemical-vapor-deposition (PECVD) system with N2 gas before the laser-crystallization. The grain-size of the laser-crystallized polycrystalline silicon (poly-Si) film with 600 seconds of radical-treatment time was remarkably increased by the relaxation of solidification process caused by the possible evolution of solid phase SiNx compounds which shows the low thermal conductivity. The electrical conductivity at 30 °C was rather lager value of 3×10-5 Ω-1cm-1 than 1×10-5 Ω-1cm-1 of poly-Si without radical treatment, while the highly resistive SiNx compounds were formed. From the SEM images, the surface roughness was also improved by the selective etching of the 5%-water-diluted hydrofluoric (HF) acid on the grain boundaries which the SiNx compounds were well segregated into during the laser-crystallization.


1983 ◽  
Vol 23 ◽  
Author(s):  
T. P. Smith ◽  
P. J. Stiles ◽  
W. M. Augustyniak ◽  
W. L. Brown ◽  
D. C. Jacobson ◽  
...  

ABSTRACTFormation of buried insulating layers and redistribution of impurities during annealing are important processes in new semiconductor device technologies. We have studied pulsed ruby laser and furnace annealing of high dose (D>1017 N/cm2) 50 KeV nitrogen implanted silicon. Using He Back scattering and channeling, X-ray diffraction, transmission electron microscopy, and infrared transmission spectroscopy, we have compared liquid and solid phase regrowth, diffusion, impurity segregation and nitride formation. As has been previously reported, during furnace annealing at or above 1200C nitrogen redistributes and forms a polycrystalline silicon nitride (Si3N4 ) layer. [1–4] In contrast, pulsed laser annealing produces a buried amorphous silicon nitride layer filled with voids or bubbles below a layer of polycrystalline silicon.


2013 ◽  
Vol 210 (12) ◽  
pp. 2729-2735 ◽  
Author(s):  
Ingmar Höger ◽  
Thomas Schmidt ◽  
Anja Landgraf ◽  
Martin Schade ◽  
Annett Gawlik ◽  
...  

2018 ◽  
Vol 924 ◽  
pp. 490-493 ◽  
Author(s):  
Muhammad I. Idris ◽  
Nick G. Wright ◽  
Alton B. Horsfall

3-Dimensional 4H-SiC metal-oxide-semiconductor capacitors have been fabricated to determine the effect of the sidewall on the characteristics of 3-Dimentional gate structures. Al2O3 deposited by Atomic Layer Deposition (ALD) was used as the gate dielectric layer on the trench structure. The 3-D MOS capacitors exhibit increasing accumulation capacitance with excellent linearity as the sidewall area increases, indicating that ALD results in a highly conformal dielectric film. The capacitance – voltage characteristics also show evidence of a second flatband voltage, located at a higher bias than that seen for purely planar devices on the same sample. We also observe that the oxide capacitance of planar and 3-D MOS capacitors increases with temperature. Finally, we have found that the 3-D MOS capacitor has a weaker temperature dependence of flatband voltage in comparison to the conventional planar MOS capacitor due to the incorporation of the (1120) plane in the sidewall.


Author(s):  
А.О. Замчий ◽  
Е.А. Баранов ◽  
И.Е. Меркулова ◽  
Н.А. Лунев ◽  
В.А. Володин ◽  
...  

A novel fabrication method of polycrystalline silicon by indium-induced crystallization (InIC) of amorphous silicon suboxide thin films with a stoichiometric coefficient of 0.5 (a-SiO0.5) is proposed. It was shown that the use of indium in the annealing process of a SiO0.5 allowed to decrease the crystallization temperature to 600°С which was significantly lower than the solid-phase crystallization temperature of the material - 850°С. As a result of the high-vacuum InIC of a-SiO0.5, the formation of free-standing micron-sized crystalline silicon particles took place.


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