Research Of TFT-LCD Four Mask Process

Along with the development of information display technology, display terminal has changed from traditional CRT display to flat panel display. Nowadays, TFT-LCD is widely used in our daily life and work, which has the features of being light, thin, portable and low electromagnetic emission, etc. TFT-LCD manufacture technique has been improved a lot during the past decade, which is driven by product design optimization, feature development of raw materials, equipment productivity improvement and better control of the process technique. One of the most important improvements is the TFT manufacture process, which changes from 7 Mask Photo Resist Process to 4 Mask Photo Resist Process. This improvement greatly reduces the manufacture cost and the TFT-LCD product prices are accepted by more and more customers.This thesis illustrates the structure and manufacture technical basis of TFT and TFT-LCD and focuses on the 5 Mask Photo Resist Process which is widely used in this industry. The author also makes a research on the development and design of gray tone photo mask, and concludes the 4 Mask Photo Resist Process can be developed, which will reduce the manufacture cost.At the same time, the author also performs tests for problems normally found in manufacture process, such as the impact of slit design to photo resist in Drain/Island, active tail remain, metal remain, etc.The development and application of 4 Mask Photo Resist Process helps to reduces manufacture cost, and brings good economic benefits to the enterprise. At the same time, it is also a landmark in the development history of TFT-LCD manufacture technique in China.