Buffer-Free Quasi-Single-Crystalline Ge/Gesn-On-Si Heterostructure and Avalanche Photodetectors for Opto-Electronic Integrated Circuits

The idea of using light beams to replace metallic wires now progressively dominates the development of data/signal communications. In recent years, electronic–photonic synergy has become an increasingly potential solution to the extension of functionality of Moore's law since it combines the merit of photons in data transmission and electrons in data processing on a single chip. The advantages of high bandwidth and low energy consumption can be achieved simultaneously using this approach. A significant challenge is that traditionally optoelectronic devices are based on III–V semiconductors, which are not compatible with Si complementary metal-oxide-semiconductor field-effect transistor processing. Besides, the scale of germanium optoelectronics is far beyond the dimension of Si electronics due to the need of strain relaxing buffer layers. And yet, the integration of optical waveguided transmission and information processing has not been demonstrated in a single chip, only conceptual demonstration. In this research project, we will demonstrate an ideal solution for monolithic electronic–photonic integration by the single crystalline Ge and GeSn alloy mesa, and the investigation of its characteristics. The electrical characteristics of Ge/GeSn heterostructure photodetector would be also studied and the potential applications on high-frequency transmission would be demonstrated.The project will be conducted in one year through materials growth and design, Raman spectra, microelectronics processing and device measurement. The potential incorporation as well as the compatibility of Ge and GeSn alloy in the optoelectronic elements to correlate with circuitry would be demonstrated in this research project.