PhD Defense of Flore BOYER

In the present context of the Big Data era, the requirement for higher density data transmission is of the utmost importance, since the demand in terms of data exchange has been growing for over 20 years. As a result, innovative means of communications have inevitably emerged, such as optical devices and interconnections. The later consist in technologies such as emitters (laser) and receptors (photodetector), made from III-V materials and integrated onto 300 mm CMOS Si-based circuitry: this what Silicon photonics is about. The latter indeed offers the possibility to meet the growing demand in data exchange, while (i) leveraging the benefits offered by the maturity of the 300~mm CMOS Si fab-line, such as high-volume production and low cost, combined with (ii) the use of optical circuitry made from III-V materials, granting reduced power consumption and high-performance chips. In the scope of optimizing the performances of such optoelectronic circuit, an innovative integration scheme has been developed in collaboration with STMicroelectronics and CEA-Leti. It consists in the full integration of the III-V emitter, which is a III-V/Si hybrid laser, onto a silicon wafer in a 300-mm CMOS-compatible clean room. One of the key components required for such integration is the development of CMOS-compatible contacts on both n-InP and p- In0.53Ga0.47As, which are the n- and p- contact layers of the III-V/Si hybrid laser, necessary for the generation and amplification of the optical signal. In this way, the goal of this PhD thesis lies in the development of these innovative contacts, meeting specific requirements, and allowing the full integration of the III-V/Si hybrid laser onto a 300 mm Silicon Photonics wafer. In this way, the eligibility of four metallization, hence eight systems, are thoroughly investigated. The systems are namely Ni/InP, Ni/In0.53Ga0.47As, Ni0.9Pt0.1/InP, Ni0.9Pt0.1/In0.53Ga0.47As, Ti/InP and Ti/ In0.53Ga0.47As. To do so, the formation phase sequence, layer morphology, element distribution and electrical properties of the enounced systems are studied. In addition, a reliability study has been performed on the systems, providing valuable and exclusive information regarding the evolution of the properties of the systems throughout subsequent process steps such as W-plug-filling and Back-End-Of-Line, as well as throughout the emulation of long-term thermal stress. Ultimately, a promising and reliable metallization is proposed for the full integration of the III-V/Si hybrid laser onto a 300~mm Si fab-line.
 

• Quentin RAFHAY -  MCF -  University Grenoble Alpes : PhD Supervisor
• Guilhem LARRIEU - Researcher - CNRS LAAS : Reviewer
• Khalid HOUMMADA - Professor - University Aix Marseille : Reviewer
• Isabelle SAGNES - Research Director - CNRS C2N : Examiner
• Philippe Rodriguez - CEA Leti : Supervisor
• Magali Grégoire - STMicroelctronics : Supervisor
• Christophe Jany -CEA Leti : Guest member