The Advantages of TFT LCD Display part one

TFT technology was developed in the 1990s. It adopts new materials and new processes for large-scale semiconductor all-integrated circuit manufacturing technology. It is used for liquid crystal (LC), inorganic and organic thin-film electroluminescence (EL and OEL) flat panel displays. Base. TFT is a non-single wafer such as a glass or plastic substrate (of course, it can also be on a wafer) through sputtering and chemical deposition processes to form various films necessary for manufacturing circuits, and large-scale semiconductor integrated circuits (LSIC) are manufactured by processing the films. . The use of non-single crystal substrates can greatly reduce costs, and is an extension of traditional large-scale integrated circuits to large-area, multi-function, and low-cost directions. It is more technically difficult to manufacture TFTs that control the switching performance of pixels (LC or OLED) on large-area glass or plastic substrates than to manufacture large-scale ICs on silicon wafers. The requirements for the production environment (purification degree is 100), the requirements for the purity of raw materials (the purity of electronic special gas is 99.999985%), and the requirements for production equipment and production technology exceed the large-scale integration of semiconductors. It is the top of modern large-scale production. Technology. Its main features are:

(1) Large area: The first generation of large-area glass substrate (300mm×400mm) TFT LCD production line was put into production in the early 1990s. By the first half of 2000, the area of ​​the glass substrate had been expanded to 680mm×880mm), and the size of the glass substrate was 950mm×1200mm. The glass substrate will also be put into operation. In principle, there is no area limitation.

(2) High integration: The 1.3-inch TFT chip used for liquid crystal projection has a resolution of XGA containing millions of pixels. The 16.1-inch TFT array with a resolution of SXGA (1280×1024), the film thickness of amorphous silicon is only 50nm, and the TABONGLASS and SYSTEMONGLASS technologies, the integration level of its IC, the requirements for equipment and supply technology, and the technical difficulty exceed the traditional ones. LSI.

(3) Powerful functions: TFT was first used as a matrix addressing circuit to improve the light valve characteristics of liquid crystals. For high-resolution displays, through voltage adjustment in the range of 0-6V (typically 0.2 to 4V), precise control of the object is achieved, making it possible for the LCD to achieve high-quality and high-resolution displays. TFT-LCD is the first flat panel display in human history that exceeds CRT in display quality. And people begin to integrate the driver IC on the glass substrate, and the function of the entire TFT will be more powerful, which is unmatched by traditional large-scale semiconductor integrated circuits.

(4) Low cost: Glass substrates and plastic substrates fundamentally solve the cost problem of large-scale semiconductor integrated circuits, and open up a broad application space for the application of large-scale semiconductor integrated circuits.

(5) Flexible process: In addition to sputtering, CVD (Chemical Vapor Deposition) MCVD (Molecular Chemical Vapor Deposition) and other traditional processes for film formation, laser annealing technology has also begun to be applied, which can produce amorphous films, polycrystalline films, and Single crystal films can be manufactured. It can not only make silicon film, but also make other Ⅱ-VI group and Ⅲ-V group semiconductor thin films.

(6) The application field is wide. The LCD panel display based on TFT technology is the pillar industry of the information society, and the technology can also be applied to the rapidly growing thin film transistor organic electroluminescence (TFT-OLED) flat panel display. Growing.