Evaluation of the reliability of high radiance Burrus diodes

Results are reported of life tests conducted under five conditions of constraint (temperature current) on Burrus diodes, emitters at 0.9 mm, belonging to two generations of devices. Analysis of failures identified two dominant modes of degradation: dark line effect defects, and dark spot defects. The percentage of bright devices increased among the second generation diodes, confirming improvement of technology. Numerical analysis led to the formulation of an hypothesis of a functional between average life and constraints; consequently, a MTBF of 2/8 time 10 to the 4th power h was extrapolated for the dark diodes and a MTBF of approximately 5.5 times 10 to the 6th power h was extrapolated for the bright devices. Life tests conducted on a small number of diodes isolated by implantation, shows that the technology, at present, is still not perfected.