The Research Of The High Aperture Ratio’s The Pixel Design And The Picture Quality Improvement

In recent years, with the continuous development of the fierce market competition and TFT-LCD technology, the image quality enhancement (aperture ratio, crosstalk, etc.) has become the most important issue of the TFT-LCD companies. In order to have great improvement in image quality; companies keep improving technical capability so as to adapt to market needs. Therefore, the image quality has become the sustainable development direction of TFT-LCD in the display area. This article focuses on research about how to improve vertical crosstalk and provides a reference for the future.1. In the silicon nitride deposition conditions of experimental analysis and study, fully analysing the effects of changing parameters on the film quality:(1) as the temperature increases the deposition rate of the film increases, the silicon nitride film refractive index also increases with increasing temperature; the uniformity of the film changed for the better after the variation with increasing temperature.(2) the greater the RF power, the faster the deposition rate, and the deposited silicon nitride film structure is dense, the film refractive index decreases, but the RF power cannot be too large, otherwise too fast deposition rate leads to lower uniformity of the film, loose structure and reduced passivation;(3) As the pressure increases, the deposition rate increases, the reaction pressure is greater than1000mtorr to ensure the plasma in the particular structure of the reactor to produce normal and stable glow discharge; and the experimental data show that when the pressure is higher than1500mtorr, the silicon nitride film uniformity is poor, having a significant adverse impact on the quality of the film, besides the pressure has little effect on the refractive index.(4) With the increase of SiH4/NH3, the film growth rate increases, but with the increase of its proportion of the increase in film growth rate becomes slow, and in order to ensure the device is functioning properly, this ratio should be less than240sccm/720sccm; the refractive index of the film also increases with increasing SiH4/NH3, at the same time changing for better.2. In the analysis of influences of PVX passivation layer on TFT characteristics and TFT array structure, the PVX passivation layer between Resin Layer and S/D layer can improve the fault phenomena of Resin and S/D direct connection; and when the thickness of PVX reaches about300A, smaller Ioff will be obtained, the TFT characteristics improved as well. It also reduces the possibility of vertical crosstalk rising resulting from TFT leakage.3. By changing the design of pixel structure, increasing the Resin thickness, reducing the dielectric constant of the Resin material or decrease of ITO between Data and the Pixel Overlap value can achieve the purpose of improving the vertical crosstalk within the process conditions. In the actual test, when Resin thickness reduces from3μm to2.5μm, Crosstalk decreases from5.1%to2.9%.