The methods of microwave-detected photo-induced current transient spectroscopy (MD-PICTS) and microwave-detected photoconductivity (MDP), which proved themselves as very successful for defect investigations in GaAs wafers, were applied to Fe-doped SI-InP samples. It was possible to observe characteristic defect levels. One important defect center showed a similar behavior as the well known EL2 defect in GaAs. This defect exhibits positive and negative PICTS signals depending on the Fe concentration. The associated activation energies show that these signals can be interpreted as an interaction of the Fe2+/3+ level in InP with both, the valence and the conduction band.
Beside this major defect we discovered a wide range of shallow defects which may be important for material properties.
This result and successful microwave detected photoconductivity mappings of InP wafers show that the new non-destructive investigation methods provide valuable information on defect distribution and characteristics.