Active Interface Characteristics of Heterogeneously Integrated GaAsSb/Si Photodiodes

TL;DR

This paper investigates the integration of GaAsSb with silicon to create efficient photodiodes for 1550 nm applications, comparing transfer methods and analyzing interface quality and photo-response.

Contribution

It introduces and compares two epitaxial layer transfer techniques for GaAsSb/Si integration and characterizes the resulting heterostructure interfaces and device performance.

Findings

High-quality, defect-free interfaces confirmed by AFM and TEM.

Effective photo-response at 1550 nm demonstrated at room temperature and 200 K.

Comparison of ELO and MTP transfer methods for GaAsSb films.

Abstract

There is increased interest in the heterogeneous integration of various compound semiconductors with Si for a variety of electronic and photonic applications. This paper focuses on integrating GaAsSb (with absorption in the C-band at 1550nm) with silicon to fabricate photodiodes, leveraging epitaxial layer transfer (ELT) methods. Two ELT techniques, epitaxial lift-off (ELO) and macro-transfer printing (MTP), are compared for transferring GaAsSb films from InP substrates to Si, forming PIN diodes. Characterization through atomic force microscopy (AFM), and transmission electron microscopy (TEM) exhibits a high-quality, defect-free interface. Current-voltage (IV) measurements and capacitance-voltage (CV) analysis validate the quality and functionality of the heterostructures. Photocurrent measurements at room temperature and 200 K demonstrate the device's photo-response at 1550 nm, highlighting the presence of an active interface.