Alfio Zanchi

                We present process probes useful to investigate the process-dependent quality 
                of p-n junctions in semiconductors. The probes are sensitive to the presence 
                of thermal generation centers, which ignite macroscopic current avalanches. 
                Since the carrier generation events are promoted by the presence of localized 
                imperfections such as dislocations, stacking faults, etc., the avalanche ignition rate 
                represents a suitable figure of merit for ranking the overall process cleanliness. 
                In particular, by using these probes we report a non-uniform distribution of 
                lattice defects within certain junctions. This phenomenon has been verified 
                by means of standard etching and infrared optical inspection. Some technological 
                hints are finally provided, capable of reducing the defectivity and improving 
                the fabrication of microelectronic devices.

                Manufacturing process quality; p-n junctions; process control monitors; 
                avalanche ignition rate; SPAD (Single Photon Avalanche Diode); thermal 
                generation centers; defect-induced carrier generation; circular junctions; 
                stretched junctions; microelectronic devices.