Research On Cu And COA Process And Its Influence On The Characteristics Of IGZO TFT Based On Advanced TFT-LCD Lines

With the construction of high generation(>G8.5)TFT-LCD,the trend of future product trend,large size,high resolution and high refresh frequency is more and more obvious.The Cu+COA technology needed is more clear,and the introduction of IGZO will become the key.This paper focuses on products based on high generation TFT-LCD line,large size,high resolution and high refresh rate,which requires RC Delay to be better,so Cu wiring technology is necessary.This paper mainly from the production process of Cu on the Cu sputtering power increased,cell size increases,the resistivity decreases,this part of the experience will affect the plate deposition uniformity;elevated Cu sputtering temperature,the main effect of Cu showed that the roughness of the parts in the production process is easy to form Hillock,resulting in products the incidence rate of ESD;Cu sputtering pressure in Cu cell and Cu show that the effects of roughness and resistivity of Cu weak correlation.At the same time,the influence degree of Cu warpage was studied:film forming temperature>film thickness>glass elastic modulus.For the selection of the thickness of the adhesive layer and the barrier layer of the Cu process,the Mo of the adhesive layer tends to be thinner,and the normal 150A thickness can be reached.The thickness of the barrier Mo is 300A which can be increased or decreased with the effect of the process.The CuNx effect is reduced by dry process,and the CuCl.by-products can be reduced by the use of NF3 gas without Cl2 etching.It is found that TFT Stress Delta Vth variability is reduced without the use of Cl2.COA is made of RGB color resistance on Array substrate,which can greatly increase the distance between Pixel and Gtae/Data Line.CO A products can greatly reduce Cpg and Cpd capacitance,and greatly reduce the RC delay.This paper mainly expounds the characteristics of COA products from the process and design.The processing side:COA product,the key management parameter is RGB stacked cow horn(Tsuno)height,and the main benefit factor that affects the cow horn height is RGB color resistance taper management.The slower taper,the smaller the cow horn height;the shorter the development time,the slower the taper.The design side:Test key test the EF value of RGB design,select the appropriate Mask Design Rule,and design the opening area with the color resistance,effectively remove the volatile gas in the color resistance during the subsequent high temperature process,and avoid TFT-LCD air bubble occurrence.This paper also studies the technology of Cu+COA+IGZO BCE TFT,and finds that IGZO TFT has natural advantages in COA process.After RGB oven for many times,the overall Vth convergence uniformity becomes better,the Mobility increases,and the traffic becomes smaller.At the same time,it decreases significantly.In addition,because of the COA process,the TFT can cover the color resistance,the stronger the water gas ability,the better the stability of the device.