The hydrogenated amorphous silicon (a-Si:H) Alms on molybdenum coated glass substrates were microstructured by irradiating the films using KrF excimer laser with a slope beam profile. By varying the laser processing parameters i.e., the laser pulse energy, the number of laser pulses and the laser energy distribution along the sample scan directions, the homogeneous, high density, and conical polycrystalline silicon features can be fabricated on the thin film surfaces. The electron field emission measurement results show that this kind of laser processed a- Si:H films possess good field emission characteristics with a low turn on electric field of less than 15 V/mum and a larger saturation emission current. The diode configured field emission display devices have been demonstrated by using the laser irradiated a- Si:H films as the electron cold cathode emitters.