Optical evaluation of spatial carrier concentration fluctuations in doped InP substrates

Nondestructive electrical characterization of LEC and VGF grown InP:S substrates is achieved with innovative photoluminescence line shift topography. The optical data, satisfactorily in agreement with band-gap renormalization and band filling theory, are absolutely calibrated against Hall effect measurements in the range 2.10(exp17) cm3 up to 2.10(exp19) cm-3. The 70 µm lateral resolution and 1 % sensitivity of the fall wafer carrier concentration imaging allow to discern characteristic variations, such as doping striations.