Wave-Guided Lateral-Configured Ge-Ge-Si Photodetectors Obtained by Rapid Melting Growth Technique

The synergy of photonic and electronic signal transmission in the near-infrared spectrum is an ideal solution for optoelectronic integrated circuits in high-speed communication systems. In this study, we fabricated high-quality germanium mesa on Si by rapid-melting growth technique for a PIN photodetector. The quality of Ge was investigated through standard Raman spectroscopy and electronic microscopy. Rather than a single-crystalline Ge mesa, a polycrystalline structure differs from those of our previous reports, and may be caused by the multiple vicinities with oxide and Si. Ge/Ge/Si PIN photodetector and a Si waveguide was fabricated and measured to study the photodetector's I-V characteristics at near-infrared spectrum. The normalized power-dependent current enhancement and photoresponsivity were investigated to reveal the effect of Ge mesa quality. This study demonstrated that a high-quality Ge mesa can be employed for optoelectronic integrated circuit with high photoelectric conversion efficiency and responsivity by a Si-based integrated circuit fabrication process.