1.3-μm buried-heterostructure lasers using a CH₄ reactive-ion-etched mesa structure grown by metalorganic vapor phase epitaxy

This paper reports of our study on using dry etching and metalorganic vapor phase epitaxy (MOVPE) to fabricate of buried-heterostructure (BH) InGaAsP-InGaAsP strained layer MQW lasers. With a dry-etched mesa there was anomalously large Zn diffusion into the mesa structure and it seriously degraded the lasing characteristics. Therefore, we inserted a buffer layer between the side wall of the dry-etched mesa and the p-InP current blocking layer. The buffer layer almost entirely eliminates Zn diffusion without changing the mesa geometry unlike the wet-etching treatment of the mesa structure. Fabricated lasers show high performance, high uniformity and good reliability