Tensile-Strained Germanium-on-Insulator Substrate Fabrication for Silicon-Compatible Optoelectronics

TL;DR

This paper introduces a method to create high-quality tensile-strained germanium-on-insulator substrates suitable for silicon-compatible optoelectronic devices, verified through structural analysis and photodetector performance testing.

Contribution

A novel fabrication process for wafer-scale tensile-strained germanium-on-insulator substrates compatible with CMOS manufacturing.

Findings

Achieved 0.16% biaxial tensile strain in germanium films.

Demonstrated photodetectors with response beyond 1.55 μm.

Fabrication process compatible with existing CMOS technology.

Abstract

We present a method to fabricate tensile-strained germanium-on-insulator (GOI) substrates using heteroepitaxy and layer transfer techniques. The motivation is to obtain a high-quality wafer-scale GOI platform suitable for silicon-compatible optoelectronic device fabrication. Crystal quality is assessed using X-Ray Diffraction (XRD) and Transmission Electron Microscopy. A biaxial tensile film strain of 0.16% is verified by XRD. Suitability for device manufacturing is demonstrated through fabrication and characterization of metal-semiconductor-metal photodetectors that exhibit photoresponse beyond 1.55 {\mu}m. The substrate fabrication process is compatible with complementary metal-oxide-semiconductor manufacturing and represents a potential route to wafer-scale integration of silicon-compatible optoelectronics.