MDP – microwave detected photoconductivity
The novel method MDP is well suited for both, defect investigation by e.g. injection dependent minority carrier lifetime measurements, as well as mapping of wafers or even bricks for inline metrology. It exceeds his competitors µPCD (microwave detected photoconductivity decay) and QSSPC (quasi steady state photo conductance) in terms of sensitivity, resolution and speed.
The photoconductivity, which is closely related to the diffusion length is measured by microwave absorption during and after the excitation with a rectangular laser pulse. Figure 1 displays the measurement principle for MDP and MD-PICTS measurements.