Fabrication and Characterization of the Pd-Silicided Emitters for Field-Emission Devices

Abstract

The structure of Pd-silicided field emitters based on the silicon micromachining technology has been demonstrated. The uniform and extremely sharp silicided emitters are formed using wet chemical etching, low-temperature oxidation sharpening (LTOS), metal coating, and furnace annealing. The silicided emitters are firstly identified by the bright-field, dark-field images, and diffraction patterns of transmission electron microscope (TEM). Under the applied voltage of 1100 V, the anode currents of the Pd-coated and silicided emitters are 16 µ A and 26 µ A, respectively. The values of threshold voltage V T for Pd-coated and silicided emitters are about 745 V and 785 V, respectively. The lower threshold voltage of the Pd-coated emitters is duo to the smaller emission work function of palladium. The emission work function of the Pd-silicided emitters is calculated to be 8.31 eV. Furthermore, the long and short-term current stabilities of silicided emitters is also better than that of Pd-coated ones. These results show that these silicided emitters have potential applications in vacuum microelectronics to obtain superior lifetime, reliability, and stability.