The research presented at IEDM was conducted under the IRT Nanoelec silicon photonics program. The objective of the research is to integrate hybrid III-V silicon laser sources into 200 mm photonics using CMOS-compatible processes.
The longer-term objective of the research is to achieve large-scale integration of these types of components by locally die-attaching III-V chips on silicon wafers. The latest results, presented at IEDM in December 2017, validate the majority of the fabrication processes used. A DFB-type laser was fabricated entirely on a 200 mm wafer.
In particular, a brick of processes to locally thicken the silicon to enable the optical transition with the III-V material was introduced, making the integration of the laser modular and compatible with any mature photonics fabrication line. The use of CMOS-compatible metallization (Ni and Ni2P on n-InP and P-InGaAs) for the electrical contacts was also demonstrated.
The laser presented at the conference delivers optical power of around 4mW with a SMSR of 50dB. Additional research is underway to improve and stabilize the processes and new laser designs that take into account the unique features of the integration process are also being evaluated.