Hybrid III-V/Silicon technology for laser integration on a 200 mm fully CMOS-compatible silicon photonics platform

In this paper we present the hybrid III-V/Si photonic platform developed in CEA-LETI. The overall integration is done in a fully CMOS compatible 200mm technology, scalable to 300mm wafers, leveraging the large scale integration capabilities of silicon photonics. III-V material is integrated on top of a mature silicon photonic front-end wafer through direct molecular bonding enabling the monolithic integration of light sources. DFB and DBR laser reference designs are used as test vehicules for the process validation. A modular approach is used in order to minimize the impact on the already qualified silicon-based devices. Collective III-V die bonding is proposed in this platform. CMOS compatible metallizations are used to form ohmic contact on n-InP and P-InGaAs leading to contact resistivity in the range of $10^{-6}\Omega$ .cm2. A planarized 2-metal level BEOL is used to connect the device, leading to a drastic reduction of series resistance. Finally, the funcitonnality of both types of lasers is demonstrated with SMSR up to 50dB and maximum output power of 5mW.