Youjia He

Project: UNIFORMITY OF QUANTUM DOT LASERS GROWN ON SILICON WAFERS

Lab Group: Bowers Lab

Graduate Mentor: Rosalyn Koscica

Abstract: The rapid advancement of AI and the growing demand for high-speed data transmission have motivated researchers to explore cost-effective, scalable methods for manufacturing photonic integrated circuits (PICs). One solution is the monolithic integration of quantum dot (QD) lasers on 300 mm silicon wafers as opposed to conventional quantum well (QW) lasers. QD lasers are inherently more compatible with silicon and display a higher defect tolerance than QW due to their improved carrier confinement. In contrast, QW lasers grown on silicon tend to have much shorter operational lifetime and are more susceptible to damage, whereas QD lasers demonstrate robust performance with lifetimes exceeding 20 years at 80°C (Shang et al., 2021). However, a critical challenge lies in achieving uniform quantum dot growth and fabrication across the entire 300 mm wafer. To investigate this, we analyzed wafer-level trends in material and device performance using electrical, optical, and thermal measurements. Wafer-scale photoluminescence revealed a mere 0.27% center-to-edge variation in wavelength, a 37.08% variation in emission intensity, and a 4.85% variation in full width at half maximum, indicating exceptional material uniformity. Device-level electrical and optical measurements further confirmed that performance differences between the wafer’s center and edge fell within noise error margins, suggesting that nonuniformity has minimal impact on device functionality. These findings will be shared with industry collaborators at AIM Photonics, who are actively manufacturing 300 mm wafers, which could revolutionize semiconductor technology in the next decade