MBE development of dilute nitrides for commercial long-wavelength VCSEL applications

Dilute-nitride based 1.3 /spl mu/m VCSELs are being developed at IQE for next generation metropolitan communications applications. Both MBE and MOCVD are employed and under investigation for commercial viability. Each technique has its respective advantages and disadvantages. MOCVD has proven to be the epitaxial process of choice for the short-haul applications based on 850 nm and 980 nm VCSELs, due in part to more mature mirror technology and inherently lower manufacturing costs. However, the high nitrogen composition required for long wavelength applications has been proven difficult to realize in MOCVD. On the other hand, MBE has been proven to achieve sufficiently high N incorporation for laser emission up to 1.55 /spl mu/m. The photoluminescence (PL) efficiency of the as-grown MBE InGaAsN is inferior, though, and high temperature annealing is necessary to improve the material optical properties. This post-growth annealing process imposes additional challenges on the device growth and its impact on the final device performance has not been completely characterized.