Modification of GaAs surface by low-current Townsend discharge

E L Gurevich (1) , S Kittel (1) , R Hergenröder (1) , Yu A Astrov (2) , L M Portsel (2) , a N Lodygin (2) , V A Tolmachev (2) , a V Ankudinov (2)

1 ISAS - Leibniz-Institut für Analytische Wissenschaften
2 A.F. Ioffe Physical-Technical Institute

Influence of stationary spatially-homogeneous Townsend discharge on the (100) surface of semi-insulating GaAs samples is studied. Samples exposed to both electrons and ions in nitrogen discharge at the current density j=60 µA/cm 2 are studied by means of X-ray photoelectron spectroscopy, ellipsometry and atomic force microscopy. It is shown that exposure to low-energy ions (< 1 eV) changes crystal structure of the semiconductor on the depth up to 10-20 nm, although the stoichiometric composition does not change. The exposure to low-energy electrons (< 10 eV) forms an oxide layer, which is 5-10 nm thick. Atomic force microscopy demonstrates that the change in the surface potential of the samples may exceed 100 mV, for the both discharge polarities, while the surface roughness does not increase.

Mots clés: 52.80.Dy; 68.47.Fg; 52.77.Bn; 68.37.Ps

E L Gurevich, S Kittel, R Hergenröder, Yu A Astrov, L M Portsel, et al.. Modification of GaAs surface by low-current Townsend discharge. Journal of Physics D: Applied Physics, 2010, 43 (27), pp.275302. ⟨10.1088/0022-3727/43/27/275302⟩. ⟨hal-00629972⟩