VLSI Books for Beginners

Very Large Scale Integration (VLSI), is a very vast domain and is known to be the best and most sought after field among all branches in electronics. Our idea is to bring in the basic knowledge on VLSI to our readers and for those who are interested is pursuing this field for a career. As an introduction, we shall take you readers to some of our earlier posts which gives the very basic knowledge of VLSI. VLSI mainly consists of a front end and a backend. The detailed architecture is explained in VLSI DESIGN FLOW Most demanding jobs in VLSI goes…

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Gallium Arsenide (GaAs) Fabrication

Gallium Arsenide (GaAs) Fabrication Techniques: This article is used to describe the basic fabrication methods of Gallium Arsenide (GaAs), mainly using LEC Growth process. Various methods are used for the fabrication of Gallium Arsenide (GaAs). Out of all the methods, the main growth technique that is used is the liquid-encapsulated Czochralski (LEC) growth of  GaAs  crystals from high purified pyrolytic  boron nitride (PBN) in high pressure. The GaAs crystals can be easily achieved from the above method as  the liquid-encapsulated Czochralski material grow in the <100> direction. As a results, round (100) wafers with very large diameters are obtained. The…

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Metal Semi-conductor FET (MESFET)

Metal Semi-conductor FET (MESFET) This article briefly describes the structure of MESFET , its comparison with MOSFET, D-MESFET and E-MESFET, circuit symbols, and also the characteristics of Schottky Barriers. A post on MESFET has already been discussed. TAKE A LOOK : MESFET This post also gives a brief description of MESFET and the main classification of MESFET. The gallium arsenide (GaAs) field-effect transistor (FET) is a bulk current-conduction majority-carrier device. This device is , is fabricated from bulk gallium arsenide with the help of  high-resolution photolithography as well as ion implantation method into a semi-insulating GaAs substrate. The processing of…

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Gallium Arsenide (GaAs) Devices

Gallium Arsenide (GaAs) Devices In this article, the first and second generation types of Gallium Arsenide (GaAs) devices are explained. During the last few years a number of different devices have been developed. MESFET was regarded as one of the earliest type of GaAs devices. The so-called ‘first generation’ of GaAs devices includes: Depletion-mode metal semiconductor field-effect transistor [D-MESFET] Enhancement-mode metal-semiconductor field-effect transistor [E-MESFET] Enhancement-mode junction field-effect transistor [E-JFET] and Complementary enhancement-mode junction field-effect transistor [CE-JFET] To know more about the basics of D-MESFET  and E-MESFET, click on the link below. TAKE A LOOK : METAL SEMI-CONDUCTOR FET (MESFET) To…

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Electron Velocity-Field Behaviour of Gallium Arsenide (GaAs)

Gallium Arsenide (GaAs) – Electron Velocity-Field Behaviour In this post, the graph between the electron field and the electron velocity is explained. The reason for the decrease in the drift velocity of the electrons have also been explained in detail. The charge carriers in the GaAs material that is the electrons will obtain energy as soon as an electric field [E] is applied. When the energy is obtained from the field, the electrons will also lose certain amount of energy due to collisions that occur due to optical photon scattering with the lattice. Thus, due to the gaining and losing…

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Energy Band Structure of Gallium Arsenide (GaAs)

Gallium Arsenide (GaAs) – Energy Band Structure In this article, the energy band structure of GaAs is explained with a diagram and also with respect to its comparison with Silicon. The cause of the curves in the valence band and conduction band of GaAs is thoroughly explained. Electron Mobility, a characteristic of GaAs, and its depending characteristics are also explained in detail. The light emitting diode characteristics of GaAs is also compared with Silicon. Before going into details, it is better to know the basics on GaAs in VLSI technology. Click on the link below. TAKE A LOOK : ULTRA-FAST…

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Channeling Effect of Gallium Arsenide (GaAs)

Gallium Arsenide (GaAs) – Channeling Effect This article explains the channeling effect of Gallium Arsenide (GaAs), and its orientation dependency. The concept of axial channeling is also explained. Before going into details, it is better to know the basics on GaAs in VLSI technology. Click on the link below. TAKE A LOOK : ULTRA-FAST SYSTEMS AND GaAs VLSI TECHNOLOGY The whole concept of crystal orientation becomes important when three main steps are done. The etching of the crystal Ion-implantation Passivation To know more about Ion-Implantation, click on the link below. TAKE A LOOK : ION IMPLANTATION This introduces an orientation…

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Gallium Arsenide (GaAs) Doping Process

Gallium Arsenide (GaAs) Doping This article briefly explains the compound semiconductor Gallium Arsenide (GaAs) with a figure showing the arrangement of atoms. The Gallium Arsenide (GaAs) doping process, with respect to the p-type and n-type material is also explained with diagrams. Before going into details, it is better to know the basics on GaAs in VLSI technology. Click on the link below. TAKE A LOOK : ULTRA-FAST SYSTEMS AND GaAs VLSI TECHNOLOGY TAKE A LOOK : GALLIUM ARSENIDE (GaAs) CRYSTAL STRUCTURE GaAs – A Compound Semiconductor Gallium arsenide is a compound semiconductor which may be defined as a semiconductor made…

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Gallium Arsenide (GaAs) Crystal Structure

In this post, the origin of Gallium and Arsenic, as well as the structure and properties of the Gallium Arsenide (GaAs) crystal is explained in detail. The atomic structure of Gallium and Arsenic are explained with diagrams and also compared with Silicon. The valence configuration of Ga, As and Si is also shown. Before going into details, it is better to know the basics on GaAs in VLSI technology. Click on the link below. TAKE A LOOK : ULTRA-FAST SYSTEMS AND GaAs VLSI TECHNOLOGY Gallium (Ga), a toxic material, is produced as a by-product in both the zinc and aluminium…

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Ultra-fast Systems and GaAs VLSI Technology

Ultra-fast Systems and GaAs VLSI Technology In this post, we will briefly review some of the limitations of silicon devices and then look at the emerging alternative for ultra-fast systems — gallium arsenide. Submicron CMOS technology Speed and smaller device dimensions are closely interrelated and we have already touched on the fact that the foreseeable limits on channel length for MOS transistors is in the region of 0.14 micro meters, after which further scaling down results in unworkable transistor geometry. In CMOS devices we have also seen that the p-transistors have inherently slower performance than similar n-transistors. This is primarily…

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