ABSTRACT
The mean inner potential of GaAs (14.2V), InAs (14.5V), GaP (14.5V) and InP (14.5V) has been measured by transmission electron holography in combination with convergent beam electron diffraction and high-resolution transmission electron microscopy. Transmission electron microscopy (TEM) is a valuable tool for composition measurements in semiconductors on an atomic scale of spatial resolution. Possible approaches to a quantitative TEM analysis include the direct exploitation of the mean inner potential (MIP) and the measurement of the local modulus of a chemically sensitive reflection. A direct exploitation of the MIP for TEM concentration measurements is hardly applicable in the InGaAs and InGaP systems, because the difference between the particular MIPs is insignificant compared to the typical noise level. The TEM investigations were performed with a Philips CM200 field emission gun/scanning transmission electron microscope operated at a nominal acceleration voltage of 200 key.
