SiGeSn quantum well for photonics integrated circuits on Si photonics platform: a review

Abstract

Recent studies of SiGeSn materials and optoelectronic devices hold great promise for photonics integrated circuits (PICs) on Si platform featuring scalable, cost-effective, and power-efficient. Thanks to the breakthrough of low temperature material growth techniques, device-quality level materials have been grown, following by the demonstration of light-emitting diodes, photodetectors, and optically pumped and electrically injected band-to-band lasers. While the exciting developments in bulk devices were reported, the quantum wells (QWs) have been investigated targeting the dramatically improved and/or novel device performance via variety of quantum confinement effects. In this review, we summarize the recent progress on development of SiGeSn QWs, including the fundamental optical and transition studies and optoelectronic device applications. The inspirational results reveal the possibility of all-group-IV PICs with photonics and electronics monolithically integrated on a single-chip.

High-κ Gate Dielectric on Tunable Tensile Strained Germanium Heterogeneously Integrated on Silicon: Role of Strain, Process, and Interface States

“…As the industry is adopting high mobility Ge and SiGe channel materials, − and ε-Ge has recently been experimentally reported to increase the carrier mobility than unstrained Ge, alternate measurement method to independently confirm strain in Ge is important for scientific research as well as for technological considerations. The strain relaxation values were further substantiated via Raman spectroscopy.…”

“…29 Recently, we have experimentally demonstrated the 2× increase in electron mobility of the biaxially tensile strained (1.6%) epitaxial Ge (ε-Ge) layer through the In 0.24 Ga 0.76 As/In x Ga 1−x As strain template. 30 Although the potential success of this material and its related compounds (i.e., GeSn, SiGeSn) is achievable in photonics, 1,2,5,8,9 there are many challenges that need to be dealt by the microelectronic industries before Ge or SiGe can be considered as viable candidates for a transistor channel material, listing two of them: (i) monolithic heterogeneous integration of Ge or ε-Ge on Si and (ii) high-κ/ε-Ge heterointerface. The potential solution in the former is to bridge the lattice constant between the upper layer of interest (i.e., Ge, SiGe, or ε-Ge) and the Si substrate, and the latter is to insert an interface passivation layer (IPL) between the highκ/Ge or ε-Ge interface to reduce interface defects.…”

“…Group IV based materials, germanium (Ge), silicon–germanium (SiGe), and germanium–tin (GeSn), are under consideration for nanoelectronics and photonics. − Due to their high carrier mobilities, supplementing these materials along with tunable compositional In x Ga 1– x As (0.1 ≤ x ≤ 0.4) as channel materials will boost the on-current and ultimately device/circuit performance in an alternate channel CMOS, , tensile-strained Ge/In x Ga 1– x As based tunnel transistors, , energy-efficient SRAM cell architecture for ultralow voltage applications, and photonic devices. ,,, For high-performance ultralow voltage CMOS logic, RF circuits, and mixed signal low-noise amplifier circuits, it is widely accepted that InGaAs and Ge will serve as n -channel and p -channel transistor materials, respectively. ,− However, implementing these two different materials (i.e., Ge and InGaAs) on a Si wafer requires defect-controlled buffer engineering for the monolithic heterogeneous integration process rather than direct growth of Ge or SiGe on Si. Furthermore, Ge is an excellent choice for CMOS logic due to its 2.8× and 4.2× higher electron and hole mobilities, respectively, compared to Si.…”

The growth of Ge and direct bandgap Ge1−xSnx on GaAs (001) by molecular beam epitaxy

“…1,2 The tunability of GeSn lends itself to be a great candidate for the next generation of near-and mid-infrared lasers and photodetectors. 1,[3][4][5][6][7][8] However, achieving the growth of good quality GeSn with signicant Sn content is typically challenged by a lattice mismatch between the substrate and GeSn. One possibility is to use a tuneable substrate that allows for a lattice match of different alloy compositions of GeSn.…”

Carrier Recombination Dynamics of Surface-Passivated Epitaxial (100)Ge, (110)Ge, and (111)Ge Layers by Atomic Layer Deposited Al2O3

“…Group-IV materials (i.e., Ge, GeSn, SiGeSn, SiGe) exhibit a potential application in line with quantum science and technology, due to their unique spintronic and optoelectronic functionalities valuable for qubits. − By exploiting strain and bandgap engineering of these materials via intelligent buffer engineering − and precise control of tin (Sn) composition in GeSn or SiGeSn during materials synthesis, ,,− , it will offer widespread applications in Si-compatible photonics and quantum technology, provided that one could synthesize device-quality group-IV materials. In addition, downscaling of silicon (Si) transistors was possible by changing the device geometry from planar to fin field effect transistors (FinFETs).…”