In this work, ballistic electron emission microscopy (BEEM) experiment
s with n-doped InAs tips are reported. Room temperature BEEM spectra o
btained with InAs tips show a different spectral behavior compared to
reference spectra measured with Au tips. The BEEM spectra were calcula
ted with an extended Bell-Kaiser model for both Au and InAs tips. For
InAs tips, excellent agreement between the measured and calculated spe
ctra is obtained only if parallel momentum conservation is assumed bot
h at the Au-GaAs interface and for the tunneling processes between the
InAs tip and the Au film. At room temperature, however, tunneling via
InAs surface states and scattering inside the Au film is found to dom
inate the spectral behavior of the BEEM spectra.