Characteristics of multi GUN MgO physical vapor deposition system

Summary form only given. MgO thin film is used as a protective layer of dielectric layer in plasma display panel. The MgO film is usually coated by physical vapor deposition process, in which plasma gun or electron gun is used as a heating source. To reduce the production cost, most PDP panel makers produce several PDP panel at once by using a large glass. To make uniform MgO film on such a large glass of 100 inches, the MgO PVD evaporator should have multi plasma or electron guns. In the multi gun evaporation system, one could expect symmetric profile of evaporated film with symmetric gun condition. In the electron gun system, evaporation rate shows linear relation with electron gun power, regardless of the gun position. However, there is strong dependence of evaporation rate with gun position in plasma gun evaporation system, i.e. the profile of MgO film is not symmetric even if the plasma gun conditions of geometry, power, magnetic field and others are all symmetric. In this paper, evaporation profiles of the electron and plasma gun evaporator systems will be analyzed based on plasma dynamics. The abnormal evaporation behavior of multi plasma gun evaporation system will be explained by plasma drift motion