Search

InAlGaN-based laser diodes (LDs) can be designed to emit across a wide range of wavelengths spanning UV to green. A common challenge across all wavelengths lies in the difficulty in producing low resistance p-type InAlGaN layers. For shorter wavelength devices, the requirement of high aluminium containing p-AlGaN leads to high device series resistance. For the longer wavelength devices approaching the green wavelengths, the thermal degradation of the indium-rich quantum wells during the growth of the p-GaN and p-AlGaN cladding layers reduces the device efficiency. In this paper we discuss how BluGlass’s remote plasma chemical vapour deposition (RPCVD) technology can address these challenges through improvements to intrinsic material properties as well as enabling novel design architectures.

The unique growth conditions of BluGlass’ low growth temperature technology Remote Plasma Chemical Vapour Deposition (RPCVD) are capable of producing Activate As-Grown (AAG) buried p-GaN layers. This ability renders RPCVD a highly attractive technique to produce GaN-based Tunnel Junctions (TJ) without the complexities associated with the post-growth lateral activation steps required by MOCVD. In this paper we discuss the use of hybrid RPCVD/MOCVD TJs for MOCVD-grown ridge guide laser diode (LD) applications. The impact of both the structure and placement of the TJ on the total optical loss of the LD are investigated. TJs conforming to the strict compositional requirements in order to yield a net reduction in optical loss are demonstrated, paving the way to improved conversion efficiencies through the replacement of the highly resistive p-AlGaN cladding layers and p-type Ohmic contacts with lower resistance n-AlGaN cladding layers and n-type Ohmic contacts.