Time-resolved measurement of surface band bending of cleaved GaAs 110/ and InP 110/ by high resolution XPS

GaAs 100.and InP 100.samples were cleaved in UHV to give 110.surface in order to investigate their energy band changes using high resolution x-ray photoelectron spectroscopy XPS.measurement. It was revealed that the surface band of a heavy doped n-GaAs 110.sample bent upward 0.4 eV and that of a heavy doped p-GaAs 110.bent downward 0.3 eV to the midgap after cleavage whereas the surface band of a heavy doped n-InP 110.sample bent upward 0.1 eV and that of a heavy doped p-InP 110. bent downward 0.65 eV to the midgap. As for the causes of band bending, we excluded the possibility of surface charging, X-Ray radiation damage and the effect of residual gas in UHV during XPS measurement. The experimental results strongly suggest that the band bending process was caused by the surface lattice relaxation after cleavage. q2000 Elsevier Science B.V. All rights reserved.