Si-based III-V virtual substrates for cmos-compatible SWIR detectors

Overview

This innovative solution involves the creation of Si-based III-V virtual substrates for the development of low-cost, CMOS-compatible short-wave infrared (SWIR) photodetectors. Utilizing molecular beam epitaxy (MBE), the technology aims to grow high-quality InGaAs photodetectors on silicon (Si) substrates instead of the traditional indium phosphide (InP) substrates. This approach offers several advantages, including significant cost reduction, enhanced compatibility with existing semiconductor manufacturing processes, and the potential for high-volume production.

Technical specifications

The core of the technology is the use of ternary III-V virtual substrates grown on Si via a modified interfacial misfit approach. This method efficiently relieves strain due to the lattice mismatch through in-plane misfit dislocations, preventing threading dislocations that could impair device performance. The adjustable lattice constant of these substrates allows strain-free growth of InGaAs with customizable bandgaps, enabling tuning of the photodetector's cut-off wavelength. The process is inherently compatible with CMOS technology, facilitating integration with Si-based readout integrated circuits (ROICs).

Key features include:

• Growth of III-V substrates on Si to reduce cost by over 10x compared to InP
• Potential for high-volume manufacturing with 200-300 mm Si wafers
• Enhanced hybridization with Si-based ROICs
• Tunable photodetector performance beyond traditional InP-based devices

Technology readiness level

The research is currently at Technology Readiness Level 3, indicating active research and development with initial experimental validation. The next steps involve further development of III-V virtual substrates on Si and performance comparison with devices grown on InP, aiming to demonstrate comparable performance and material quality within a one-year timeline.