The polished nominal (100) surfaces of 4 types of diamond were exposed to atomic H by means of the hot-filament cracking of H2 gas, or immersion in a H2 plasma discharge. The (100) surfaces of both type-IIa and type-IIb diamonds exhibited a secondary electron yield increase of a factor of about 30, as measured by scanning electron microscopy. Also, near-surface non-topographical defects were directly observed by using the secondary electron mode of the scanning electron microscope. Finally, the surface conductance increased by up to 10 orders of magnitude. These changes were only weakly observed in N-containing type-Ia and type-Ib diamonds.

D.P.Malta, J.B.Posthill, T.P.Humphreys, R.E.Thomas, G.G.Fountain, R.A.Rudder, G.C.Hudson, M.J.Mantini, R.J.Markunas: Applied Physics Letters, 1994, 64[15], 1929-31