RELIABILITY OF VAPOR-GROWN INGAAS AND INGAASP HETEROJUNCTION LASER STRUCTURES

The reliabilities of vapor-grown ternary InGaAs/InGaP and quaternary InGaAsP/InP heterojunction structures have been compared. Quaternary structures have been found to have much longer operating lives than ternary structures, with InGaAsP heterojunction LED's having attained over 9000 h of operation to date at 60°C. Room-temperature CW operation of 1.25 µm InGaAsP/InP lasers also has been obtained for 4500 h, to date, without appreciable degradation. Lattice mismatch has been found to strongly limit the operating life of heterojunction diodes, even though it does not affect initial device performance. Several device processing techniques were evaluated to determine their effect on device reliability. The use of oxide-defined stripe contacts (rather than broad-area contacts), cleaved (rather than polished) facets, and Al2O3-coated (rather than uncoated) facets all were found to enhance device reliability. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc.