Updated technology of ion implantation applicable low-temperature poly-Si TFT process

Ion implantation (I/I) is very common as an ion doping method with mass separation for LSI fabrication, while the ion doping (I/D) method without mass separation is generally used for low-temperature poly-Si (LTPS) TFTs. A low-dose doping process, such as LDD doping and channel doping, in addition to high-dose doping for the source/drain, is an important key to the achievement of high-performance LTPS TFTs. The I/D method has problems of reproducibility and controllability in low-dose doping, and in removing photo-resist after the high-dose doping of the top gate structure. The I/I method is useful and effective not only for improving the problem of low-dose doping and achieving high-performance TFT characteristics, but also for improving process matters such as the difficulty of removing photo-resist, especially in high-dose boron doping.