Effects of dopant concentration, crystallographic orientation, and crystal morphology on secondary electron emission from diamond

Secondary electron emission properties from crystalline and polycrystalline diamond films containing different boron concentrations were measured. The secondary electron yields delta were high. Yields were independent of incident beam angle and crystallographic orientation. The secondary electron yields were greatest for boron concentrations of 10(19)-10(20) cm(-3). The angular distribution was peaked about the surface normal with a half width at half maximum of 37 +/- 7 degrees. The secondary electron yield decreased with prolonged energetic electron beam bombardment. The energy distribution of the emitted electrons contained a large, relatively narrow, low energy peak that disappeared with extended electron beam bombardment The large secondary electron yields and narrow energy distributions of the emitted electrons were consistent with nearly thermalized electron emission from negative electron affinity states. (C) 1997 American Institute of Physics. [S0021-8979(97)01919-1].