Tungsten microcone arrays grown using nanosecond pulsed-Nd : YAG laser in a low-pressure He-gas atmosphere

Tungsten microcone arrays with a high aspect ratio are formed by the cumula tive nanosecond pulsed-Nd:YAG laser irradiation of single-crystal tungsten under low pressure in an inert atmosphere. The morphology of the microcones and their density were strongly affected by the number of laser pulses. Th e microcones grew to a length of 20 mum with a diameter of about 1.5 mum at the tip after irradiation with more than 1200 pulses under our experimenta l conditions. They may have potential applications for emission cathodes in a field-emission display (FED) and in microelectronic devices.