In order to find out the Si FEA coating material suitable to microelectronics devices,a serial of function material grown by ion Beam assisted Deposit Technology and others have,been adopted as a coating layer.Measurement of the emission by I-V characteristics at the pressure of 10~-6Pa range revealed that all coating layer improved the emission property exceptAu, Mo and TaN coating FEA shown the highest mission current. The effective surfacework function and effective surface emission area were evaluated f...