THE EFFECTS OF PROBE SPOT SIZE AND SAMPLING GRID DENSITY ON PROCESS-CONTROL VALUES DERIVED FROM PHOTOLUMINESCENCE MAPPING

Whole wafer processing of III-V compound semiconductor materials has c reated a need for spatially resolved characterization tools. Photolumi nescence mapping has been widely adopted for this purpose. In order to make an accurate assessment of an epitaxial layer using this techniqu e, careful attention must be paid to the probe spot size and to die sa mpling statistics. In this paper we discuss both spot size and grid sp acing and demonstrate the effects of undersampling an inhomogeneous ep itaxial layer. Guidelines for the routine photoluminescence mapping of III-V epilayers are established.