Fabrication of High-Quality and Strain-Relaxed GeSn Microdisks by Integrating Selective Epitaxial Growth and Selective Wet Etching Methods

Abstract

GeSn is a promising material for the fabrication of on-chip photonic and nanoelectronic devices. Processing techniques dedicated to GeSn have thus been developed, including epitaxy, annealing, ion implantation, and etching. In this work, suspended, strain-relaxed, and high-quality GeSn microdisks are realized by a new approach without any etching to GeSn alloy. The GeSn alloy was grown on pre-patterned Ge (001) substrate by molecular beam epitaxy at low temperatures. The transmission electron microscopy and scanning electron microscopy were carried out to determine the microstructures of the GeSn samples. The microdisks with different diameters of Ge pedestals were fabricated by controlling the selective wet etching time, and micro-Raman results show that the microdisks with different dimensions of the remaining Ge pedestals have different extents of strain relaxation. The compressive strain of microdisks is almost completely relaxed under suitable conditions. The semiconductor processing technology presented in this work can be an alternative method to fabricate innovative GeSn and other materials based micro/nano-structures for a range of Si-compatible photonics, 3D-MOSFETs, and microelectromechanical device applications.

Impact of strain engineering and Sn content on GeSn heterostructured nanomaterials for nanoelectronics and photonic devices

“…146 The incorporation of Sn inside the SiGeSn barriers was controlled by the growth temperature of about 300 C. Microdisk cavities were fabricated using photolithography. [147][148][149][150] The PL spectra of MQW were obtained at different temperatures, pumping with a laser of wavelength 1064 nm. A 72 kW cm À2 peak pump power achieve dominant lasing emission at 495 meV.…”

“…Microdisk cavities were fabricated using photolithography. 147–150 The PL spectra of MQW were obtained at different temperatures, pumping with a laser of wavelength 1064 nm. A 72 kW cm −2 peak pump power achieve dominant lasing emission at 495 meV.…”

Optimal Regime for Growth of Epitaxial Germanium Layers from the Liquid Phase Based on Thermodynamic Calculations

“…The microstructures of Ge1-xSnx samples were studied by transmission and scanning electron microscopes. The results show that defects are mainly localized at the Ge1-xSnx/Ge interface [5].…”

Theoretical Investigation of Strain-Adjustable Ge0.92Sn0.08 Light-Emitting Diodes With Giant Magnetostrictive Stressor for Short-Wave Infrared Light Source

“…To avoid the growth defects caused by merely increasing the Sn content, strain engineering was taken to realize the indirect to direct bandgap transition of GeSn alloys [16][17][18]. A significant improvement of the luminous efficiency and wavelength application in the mid-infrared spectra with the tensile stressor [10,19].…”