Electric characteristics of ruthenium doped InP and its application for buried‐heterostructure lasers

In recent years, ruthenium (Ru) has been focused on the new semi-insulated doping material for InP instead of Fe. Semi-insulated InP is essential for the blocking layer of high modulation speed laser diode in terms of the capacitance and heat dissipation. In this paper, we have investigated the electric characteristic of Ru doped InP (Ru-InP) which works both electron and hole trap characteristics. We fabricated n-InP/Ru-InP/n-InP (n/Ru/n-InP) and p-InP/Ru-InP/p-InP (p/Ru/p-InP) structure by Metal Organic Vapor Phase Epitaxy (MOVPE), and evaluated I-V characteristics of its structure. It turned out from this experiment that the volume resistivity of p/Ru/p-InP structure was higher than that of n/Ru/n-InP. The resistivity of p/Ru/p-InP was almost equal to that of n/Fe/n-InP. We applied the Ru-InP to the Buried-Heterostructure DFB Laser as current blocking layer. We confirmed that the temperature dependence of LD characteristics was improved, and the output power was over 10mW even at 70 °C (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)