TFT is the short name of  Thin Film Transistor,general generation refers to the thin-film liquid crystal display, actually refers to the thin film transistor (matrix)——can be"active" control per individual pixels on the screen , this is the origin of  active matrix TFT,TFT technology was developed in 1990s,using new material and new process of a large scale fully integrated circuit semiconductor manufacturing technology,which is the  FPD   foundation of LC、 EL and OEL。TFT is essential manufacturing various  film of the circuit which is on the glass or plastic substrate, etc not-single crystal chip (of course single  crystal chip can also be)  formed by the sputtering and chemical deposition process.through processing film to make large-scale semiconductor integrated circuit(LSIC).using not-single crystal substrate can greatly reduce the cost,it Is the traditional large scale integrated circuit' extendtion of large area ,Multifunction, low cost. Making  TFT with control    On the large area glass or plastic substrate is more  difficulty than making large scale IC on the silicon chip.require the production environment (Purification degree for level 100),require the purity of raw material(Electronic gas purity is(99.999985%) ,require the produce equipmet and produce technology etc.all requirements are  more than the large-scale integrated semiconductor,it  is the top of modern production technology.TFT-LCD(Color thin film transistor liquid crystal display) is mainly used in computer, Video terminal,Communication and instrumentation and other industries.Main application fields is  laptop, desktop computer monitor, workstations, industrial monitors, global positioning system (GPS), personal data processing, game consoles, video phone, portable VCD, DVD and other portable devices. 

APG in Flat display indusrty to provide target material basically has: