Non-Destructive, Remote Testing of Silicon Wafers by Observation of Photo-Luminescence Characteristics at Room Temperature
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Jan-31
A non-destructive, remote testing of silicon wafers by the observation of photo-luminescence (PL) characteristics from a silicon wafer in an imaging mode at room temperature exposes various types of wafer defects that are detrimental to the ultimate performance of the inscribed circuitry. Flashlamps 11 (with reflectors 10) pulsed at 10 - 50 Hz, with a pulse duration of 50 - 300 mms and with a filtered (12) spectral emission of 400 - 800 nm, can be used to illuminate the wafer 13 with a power density of 50 - 100 W/cm2 (Fig. 1). Electrons and holes (EH) generated by the flashlamp 11 excitation recombine in defect-free silicon by emitting radiation in a band near 1.1 eV. Certain crystal defects will act as regions for non-radiative EH recombination, resulting in very weak local PL.