Correlation between photoluminescence lifetime and interface trap density in silicon-on-insulator wafers

We investigated the correlation between optical lifetime and interface trap density in silicon-on-insulator (SOI) wafers. The temporal decay of electron-hole droplet (EHD) luminescence exclusively from the ultrathin superficial Si layer was measured under pulsed ultraviolet laser excitation. The interface trap density of the SOI wafers in the area adjacent to the luminescence measurement region was determined by the charge-pumping method. For such wafers, the lifetime increases as the trap density decreases. The correlation between the two values is discussed on the basis of the recombination process for EHD in the SOI structure.