Field-emission properties of diamond grains grown on textured Fe/Si substrates

Diamond grains were produced by the hot-filament chemical-vapor deposition technique using a mixture of CH4/H-2 as the synthesis gas. The Si substrate s were textured (random pyramids) by chemical etching before growth of diam ond grains, because emission of electrons is facilitated at the top of the pyramids. In order to increase the diamond nucleation density, an iron thin film (Fe) was deposited on the textured Si substrate by a radio-frequency plasma sputtering technique. Moreover, partial iron thin films (20% surface coverage) were fabricated for application as field emitter displays using a metal mask. The relationship between the nucleation density and the thick ness of the iron films has been investigated by scanning electron microscop y (SEM). The samples were placed in a high-vacuum chamber with a pumping sy stem and the emission current was measured as a function of the applied vol tage. The voltage-current (V-I) characteristics were estimated for the fiel d emitter. In order to etch nondiamond components, these samples were etche d by O-2 and CF4 plasmas. SEM observation revealed that diamond growth is c oncentrated at the textured Fe/Si area. The nucleation density was 10(7) cm (-2) on the textured Fe/Si area. On the plain textured Si substrate diamond growth could not be observed. Numberless tips were observed on the Fe/Si a rea after etching. The V-I characteristics revealed a current 10(-8) Angstr om at an applied voltage of 1.8 kV. The V-I characteristics could be enhanc ed by using the textured Fe/Si substrate. (C) 2000 American Institute of Ph ysics. [S0021-8979(00)07804-X].