Elastic Strain Sharing in Silicon/silicon Germanium Nanomembranes
Title | Elastic Strain Sharing in Silicon/silicon Germanium Nanomembranes PDF eBook |
Author | Michelle M. Kelly |
Publisher | |
Pages | 156 |
Release | 2007 |
Genre | |
ISBN |
Elastic Strain Engineering in Silicon and Silicon-germanium Nanomembranes
Title | Elastic Strain Engineering in Silicon and Silicon-germanium Nanomembranes PDF eBook |
Author | |
Publisher | |
Pages | 0 |
Release | 2012 |
Genre | |
ISBN |
Strain in crystalline materials alters the atomic symmetry, thereby changing materials properties. Controlling the strain allows tunability of these new properties. Elastic strain engineering in crystalline nanomembranes (NMs) provides ways to induce and relax strain in thin sheets of single-crystalline materials without exposing the material to the formation of extended defects. I use strain engineering in NMs in two ways: (1) elastic strain sharing between multiple layers using the crystalline symmetry of the layers to induce unique strain distributions, and (2) complete elastic relaxation of single-crystalline alloy NMs. In both cases, NM strain engineering methods enable the introduction of unique strain profiles or strain relaxation in ways not compatible with conventional bulk processing, where strain destroys the long-range crystallinity. Elastically strain-shared NMs are fabricated by releasing multi-layer thin film heterostructures from the original host substrate. If one layer of the original heterostructure contains strain, the strain will share between the layers of the freestanding NM. The extent of strain sharing will depend on the relative thicknesses, the ratio of the elastic moduli between the materials, and elastic symmetry of the layers. I calculate strain distributions in flat NMs between layers with 2-fold and 4-fold elastic symmetry. I verify my calculations with experimental proof of two examples: (1) strain sharing between biaxially isotropic layers, Si/SiGe/Si(001), and (2) strain sharing between biaxially anisotropic layers, Si/SiGe/Si(110). Strain engineering in NMs is also used to relax strain elastically in thin materials that are difficult to fabricate with conventional bulk crystal growth techniques. Thin films of SiGe grow uniformly and elastically strained on Si substrates. I release the SiGe layer from the Si growth template with NM fabrication processes and allow the SiGe allow to relax elastically to the appropriate bulk lattice constant. I confirm the high structural quality and strain uniformity of these new materials, and demonstrate their use as substrates for technologically relevant epitaxial films by growing strained Si layers and thick, lattice-matched SiGe alloy layers on them. I compare the structural quality of epitaxial films grown on SiGe NMs to those grown on plastically relaxed SiGe substrates.
Silicon Nanomembranes
Title | Silicon Nanomembranes PDF eBook |
Author | John A. Rogers |
Publisher | John Wiley & Sons |
Pages | 365 |
Release | 2016-04-08 |
Genre | Technology & Engineering |
ISBN | 3527690999 |
Edited by the leaders in the fi eld, with chapters from highly renowned international researchers, this is the fi rst coherent overview of the latest in silicon nanomembrane research. As such, it focuses on the fundamental and applied aspects of silicon nanomembranes, ranging from synthesis and manipulation to manufacturing, device integration and system level applications, including uses in bio-integrated electronics, three-dimensional integrated photonics, solar cells, and transient electronics. The first part describes in detail the fundamental physics and materials science involved, as well as synthetic approaches and assembly and manufacturing strategies, while the second covers the wide range of device applications and system level demonstrators already achieved, with examples taken from electronics and photonics and from biomedicine and energy.
Strain-engineered Nanomembrane Substrates for Si/SiGe Heterostructures
Title | Strain-engineered Nanomembrane Substrates for Si/SiGe Heterostructures PDF eBook |
Author | Pornsatit Sookchoo |
Publisher | |
Pages | 0 |
Release | 2016 |
Genre | |
ISBN |
For Group IV materials, including silicon, germanium, and their alloys, although they are most widely used in the electronics industry, the development of photonic devices is hindered by indirect band gaps and large lattice mismatches. Thus, any heterostructures involving Si and Ge (4.17% lattice mismatch) are subject to plastic relaxation by dislocation formation in the heterolayers. These defects make many devices impossible and at minimum degrade the performance of those that are possible. Fabrication using elastic strain engineering in Si/SiGe nanomembranes (NMs) is an approach that is showing promise to overcome this limitation. A key advantage of such NM substrates over conventional bulk substrates is that they are relaxed elastically and therefore free of dislocations that occur in the conventional fabrication of SiGe substrates, which are transferred to the epilayers and roughen film interfaces. In this thesis, I use the strain engineering of NMs or NM stacks to fabricate substrates for the epitaxial growth of many repeating units of Si/SiGe heterostructure, known as a 'superlattice', by the elastic strain sharing of a few periods of the repeating unit of Si/SiGe heterolayers or a Si/SiGe/Si tri-layer structure. In both cases, the process begins with the epitaxial growth of Si/SiGe heterolayers on silicon-on-insulator (SOI), where each layer thickness is designed to stay below its kinetic critical thickness for the formation of dislocations. The heterostructure NMs are then released by etching of the SiO2 sacrificial layer in hydrofluoric acid. The resulting freestanding NMs are elastically relaxed by the sharing of strain between the heterolayers. The NMs can be bonded in-place to their host substrate or transferred to another host substrate for the subsequent growth of many periods of superlattice film. The magnitude of strain sharing in these freestanding NMs is influenced by their layer thicknesses and layer compositions. As illustrated in this dissertation, strain-engineering of such NMs can provide the enabling basis for improved Group IV optoelectronic devices.
SiGe, Ge, and Related Compounds 4: Materials, Processing, and Devices
Title | SiGe, Ge, and Related Compounds 4: Materials, Processing, and Devices PDF eBook |
Author | D. Harame |
Publisher | The Electrochemical Society |
Pages | 1066 |
Release | 2010-10 |
Genre | Science |
ISBN | 1566778255 |
Advanced semiconductor technology is depending on innovation and less on "classical" scaling. SiGe, Ge, and Related Compounds has become a key component in the arsenal in improving semiconductor performance. This symposium discusses the technology to form these materials, process them, FET devices incorporating them, Surfaces and Interfaces, Optoelectronic devices, and HBT devices.
Stress and Strain Engineering at Nanoscale in Semiconductor Devices
Title | Stress and Strain Engineering at Nanoscale in Semiconductor Devices PDF eBook |
Author | Chinmay K. Maiti |
Publisher | CRC Press |
Pages | 275 |
Release | 2021-06-29 |
Genre | Science |
ISBN | 1000404935 |
Anticipating a limit to the continuous miniaturization (More-Moore), intense research efforts are being made to co-integrate various functionalities (More-than-Moore) in a single chip. Currently, strain engineering is the main technique used to enhance the performance of advanced semiconductor devices. Written from an engineering applications standpoint, this book encompasses broad areas of semiconductor devices involving the design, simulation, and analysis of Si, heterostructure silicongermanium (SiGe), and III-N compound semiconductor devices. The book provides the background and physical insight needed to understand the new and future developments in the technology CAD (TCAD) design at the nanoscale. Features Covers stressstrain engineering in semiconductor devices, such as FinFETs and III-V Nitride-based devices Includes comprehensive mobility model for strained substrates in global and local strain techniques and their implementation in device simulations Explains the development of strain/stress relationships and their effects on the band structures of strained substrates Uses design of experiments to find the optimum process conditions Illustrates the use of TCAD for modeling strain-engineered FinFETs for DC and AC performance predictions This book is for graduate students and researchers studying solid-state devices and materials, microelectronics, systems and controls, power electronics, nanomaterials, and electronic materials and devices.
Silicon Photonics
Title | Silicon Photonics PDF eBook |
Author | |
Publisher | Academic Press |
Pages | 242 |
Release | 2018-10-08 |
Genre | Science |
ISBN | 0128155191 |
Silicon Photonics, Volume 99 in the Semiconductors and Semimetals series, highlights new advances in the field, with this updated volume presenting interesting chapters on Transfer printing in Silicon Photonics, Epitaxial integration of antimonide-based semiconductor lasers on Si, Photonic crystal lasers and nanolasers on Si, the Evolution of monolithic quantum-dot light source for silicon photonics, III-V on Si nanocomposites, the Heterogeneous integration of III-V on Si by bonding, the Growth of III-V on Silicon compliant substrates and lasers by MOCVD, Photonic Integrated Circuits on Si, Integrated Photonics for Bio- and Environmental sensing, Membrane Lasers/Photodiodes on Si, and more. Provides the authority and expertise of leading contributors from an international board of authors Represents the latest release in the Semiconductors and Semimetals series Updated release includes the latest information on Silicon Photonics