5 edition of Two aspects of GaAs/AlGaAs device modelling found in the catalog.
Two aspects of GaAs/AlGaAs device modelling
by National Library of Canada = Bibliothèque nationale du Canada in Ottawa
Written in English
|Series||Canadian theses = Thèses canadiennes|
|The Physical Object|
|Pagination||1 microfiche : negative.|
I have a very small (~um) GaAs p-n junction device (with AlGaAs QW) and would like to collect PL images from, using an optical microscope . 1 day ago VCSEL (vertical cavity surface emitting laser) is a promising optoelectronic device, but its high manufacturing cost limits its scope of applications. Growing on larger size wafers is an effective way to reduce the cost. However, the growth rate uniformity needs to be optimized to ensure the uniformity of the devices’ performance over the wafers. This paper investigates the factors which.
Since GaAs has higher electron affinity, free electrons in the AlGaAs layer are transferred to the undoped GaAs layer where they form a two dimensional high mobility electron gas within ångström (10 nm) of the n-type AlGaAs layer of the HEMT is depleted completely through two depletion mechanisms: Trapping of free electrons by surface states causes the surface depletion. Both models consider the device gate width and therefore both are scalable. Results of modelling of three different AlGaAs/GaAs HEMTs in a wide range of operating bias conditions using the considered approaches are given. Different modelling aspects are discussed.
Current–voltage characteristics of an inverted GaAs–AlGaAs modulation doped transistor are calculated using a charge control model. Our calculations show that the electron concentration of the two dimensional electron gas for the inverted structure is comparable to those obtained in normal MODFET’s. The optimum design of an inverted device calls for a doped AlGaAs layer thin enough to be. Abstract: This paper elucidates the stabilities of the dc current gain, ideality factor, and offset voltage against variations in temperature and currents for GaAs-based heterojunction bipolar transistors (HBTs). The InGaP/GaAs HBT markedly reduces the offset voltage and improves the temperature stability of the dc current gain relative to those of AlGaAs/GaAs benchmark devices.
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Multiple quantum wells GaAs/AlGaAs were obtained by the MBE on the GaAs () substrate with a buffer consisting of a μm GaAs layer. The doped GaAs layers of μm thickness were used as a base contact, whereas the upper ohmic contact was provided by the doped GaAs of μm : Michael A.
Dem'yanenko, Dmitry G. Esaev, Natalia A. Valisheva Aleksandr I. Toropov, Sergey A. Dvoret. The model takes into consideration the effects of the design parameters including concentration levels, structural properties of the device (well length, etc.), operating temperature and electric field effects.
The results generated are for a bare AlGaAs/GaAs cell and the same cell with a Cited by: 8. Just as in Si devices, the seeds of GaAs contact reliability problems are often planted during processing.
A good example is reproduced in the transmission electron microscopic cross-sectional image of a high-electron-mobility transistor contact structure (Figure ).Due to a 1–2 nm thick oxide barrier between the metallization and underlying AlGaAs, metal alloying occurred nonuniformly.
Abstract: Device models for GaAs devices and GaAs/AlGaAs heterostructures are much less advanced than those for silicon devices. The author critically reviews recent advances in the modeling of GaAs/AlGaAs devices. The review is based on an examination of five selected device models that contain features common to the majority of device models for heterostructure bipolar and field effect.
Results of modelling of three different AlGaAs/GaAs HEMTs in a wide range of operating bias conditions using the considered approaches are given. Different modelling aspects are discussed.
A pnpnpn AlGaAs/GaAs heterostructure has been used in the simulation of the RT-SCR device. The circuit given in Fig.
1 is used to model the RT-SCR structure. It is the modified two-transistor model, which has T 1 as a traditional pnp bipolar transistor and T 2 as an RTT.
Download: Download full-size image Fig. Here, we design and engineer an axially asymmetric GaAs/AlGaAs/GaAs (G/A/G) nanowire (NW) photodetector that operates efficiently at room temperature. Based on the I-type band structure, the device can realize a two-dimensional electron–hole tube (2DEHT) structure for the substantial performance enhancement.
The 2DEHT is observed to form at the interface on both sides of GaAs/AlGaAs. The composition n-GaAs–p-GaAs–p-AlGaAs (Fig. 1A) was the first widely used structures were grown by LPE [3–14] or by MOCVD [21,22].For example, a μm-thick p-GaAs layer is either grown epitaxially (MOCVD) or formed by zinc or beryllium diffusion during the growth (LPE) of the Al x Ga 1– solid solution doped with one of these impurities.
Gold, in Silicon–Germanium (SiGe) Nanostructures, Model. We consider an interacting two-dimensional electron gas in the xy-plane with an in-plane effective mass m* = m e and confinement in the z-direction. m e represents the free electron mass.
The effective mass perpendicular to the xy-plane is m z = m e, m z being important for IRS in the case of QWs and for. Gallium arsenide (GaAs), or more generally the AlGaAs system, is particularly interesting because it exhibits a huge second-order nonlinearity (d 14 ~ pm/V), a broad transparency window (from to 17 μm), and a large variety of design and fabrication solutions.
Because AlGaAs is neither birefringent nor ferroelectric, phase matching is. Modeling for electron transport in AlGaAs/GaAs/AlGaAs double-heterojunction structures Abstract: Two-dimensionally quantized electron transport in modulation-doped double-heterojunction structures is investigated using a Monte Carlo simulation in which the energy quantization in a well is considered.
Photoluminescence (PL) measurements at a wide temperature range, up to room temperature, for high-quality and high-density GaAs/AlGaAs quantum dots (QDs) fabricated by droplet epitaxy were carried.
The two-dimensional device simulator PISCES incorporates a set of III-V models and examples for GaAs-based, AlGaAs/InGaAs, InAlAs/InGaAs MESFETs and HEMTs. Further AlGaAs/GaAs, InP/InGaAs, and InGaP/GaAs HBTs are simulated.
G-PISCES, a development by Gateway modeling, also demonstrated the simulation of AlGaN/GaN HEMTs. The two- and three. 1. Introduction. Quantized Hall resistors (QHRs) made with alloyed AuGe/Ni ohmic contacts to GaAs/AlGaAs heterostruc-tures are quite widely used as resistance standards by many national standards laboratories [1, 2].These devices are repeatedly cooled and warmed between room temperature and temperatures below K over periods of many years.
To model the capture process in a laser device or in a time-resolved experiment, it is in general necessary to consider the capture AlGaAs/GaAs/AlGaAs region. GaAs-z 0 b 2 w + Figure 1. Energy band proﬁle of the separate conﬁnement heterostructure quantum well consisting of the GaAs quantum well between two AlGaAs barriers and.
Main Fabrication of GaAs Devices. Fabrication of GaAs Devices Baca, Albert G., Ashby, Carol I.H. This book provides fundamental and practical information on all aspects of GaAs processing.
The book also gives pragmatic advice on cleaning and passivation, wet and dry etching and photolithography, and dry etching. Other topics covered include. The GaAs/AlGaAs modulation-doped heterostructure presents a two-dimensional electron gas (2DEG) confined to the interface between the AlGaAs and the GaAs layers.
These samples are grown by molecular beam epitaxy to obtain a low impurity density which, combined with the modulation-doping technique, leads to high electron mobility in the 2DEG.
Abstract: Presented in this paper are investigations regarding the influence of doping concentration in RTD barriers and on IV-characteristics. One-band combined RTD model is based on semiclassical and quantum-mechanical (the wave-function formalism) approaches.
It takes into account the effect of charge in different regions, including surface charge at heterointerfaces, the shape of. Most current techniques for analyzing amino acids require substantial instrumentation and significant sample preprocessing.
In this study, we designed, fabricated, and tested a scalable diode-based. Data presented in Table 2 show that for AlGaAs/GaAs HPT-1δ the optimal value of the broadening of the Gauss dopant distribution W δ is 10 nm (f T = GHz, K= dB).
In the case of AlGaAs/GaAs HPT-2δ structures, the best device parameters (f T = GHz, K= dB) were obtained for W δ = 8 nm and distance between two delta-doped. Device characteristics of AlGaAs/GaAs heterostructure field effect transistors fabricated by molecular‐beam epitaxial growth are related to the condition of the substrate‐epitaxial layer interface.
The presence of carbon on the GaAs wafer surface prior to growth has been found to produce a p‐type, conducting interfacial region. We demonstrate that the concentration of carbon on the wafer. An N ++-GaAs/P ++-AlGaAs tunnel junctions (TJs) structure has been used for connecting each sub-cell in this vertically-stacked PPC device.
The thickness of the each GaAs sub-cell has been derived based on the calculation of absorption depth of photons with a wavelength of nm using absorption coefficient obtained from ellipsometry measurements.Gallium arsenide ranks second to silicon with regard to two primary aspects; it is a wider bandgap semiconductor suitable for high-temperature operation and with technological maturity.
The high electron mobility in GaAs together with its direct bandgap make this material a strong competitor to silicon for the fabrication of high-temperature.