A configuration of carbon nanotubes (CNTs) whose surfaces were fully covered with nanoscale nodes was developed in our laboratory. We named this material nodular CNTs or NCNTs. A hydrogen plasma process was used to turn common CNTs into NCNTs. Combined with this process, a technique has been developed to make planar NCNTs field emitters. Field emission experiments showed that planar NCNTs emitters had superior field emission characteristics. Specifically, the emission site density was increased by the order of 10(6)/cm(2). A suggestion was given to interpret the formation of NCNTs and a simple model was also proposed to explain the improvement of field emission properties. This technique was found to be an easy way to change the geometric character of CNTs in large quantities and will be useful for creating planar field emitters used in field emitter light sources or display devices. (C) 2003 American Vacuum Society.