All about Semiconductor
Semiconductor Basics – What is Semiconductor, Types, Material, Physics and More.
A semiconductor can be defined as a substance with properties of a conductor and insulator both.
It can conduct electricity under certain circumstances but not always. This physics and property of a semiconductor makes it a good medium to use electricity in a controlled manner as and where required. Conductance of a semiconductor depends on several factors such as current or voltage applied to a control electrode, or on the intensity of irradiation by infrared (IR), visible light, ultraviolet (UV), or X rays.
So, we can say that a semiconductor is a material that has electrical conductivity greater than an insulator but less than a conductor.
Examples of a semiconductor: Diodes, transistors, and many photovoltaic cells.
Semiconductor – Facts and Physics
As I mentioned above, a semiconductor has a dual property – conductor and insulator of electricity. This property depends on impurities added to the semiconductor material (A pure semiconductor is called an “intrinsic” semiconductor). The impurities added to the semiconductor material to change its electrical property are called “dopants” and the process of adding impurities to the pure semiconductor material is called doping.
Types of Semiconductors
Semiconductors are of 2 Types:
- An N-type semiconductor is one that carries current in the form of negatively-charged electrons. This is very similar to conduction of current in a wire.
- A P-type semiconductor is one that carries current predominantly as electron deficiencies called holes. A hole has a positive electric charge. This charge is equal and opposite to the charge on an electron. These holes flow in the opposite direction of electrons.
Function / Application of a Semiconductor
A semiconductor can help controlled flow of electricity. The basic function of such a device is to switch ON and OFF the flow of electricity as and when required. A semiconductor device can perform the function of a vacuum tube with hundreds of times its volume. A single integrated circuit (IC), such as a microprocessor chip, can do the work of a set of vacuum tubes.
There are several materials and elements used to make semiconductor. The basic requirement is that the material should not be a very good conductor of electricity, nor should it be a very bad conductor of electricity. Its properties can be changed by adding or removing atoms / impurities.
Semiconductor materials include – antimony, arsenic, boron, carbon, germanium, gallium arsenide, selenium, silicon, silicon carbide, sulfur, tellurium, oxides of most metals.
Silicon is the most widely used semiconductor material.
What is Superconductor?
Superconductor is an element, inter-metallic alloy, or a compound that conducts electricity without resistance below a certain temperature.
Once set in motion, electrical current will flow forever in a closed loop of a superconducting material.
A Diode is an electronic component that allows current to flow in one direction only. It is a device that consists of a p-n junction. They are used most commonly to convert AC to DC, because they pass the positive part of the wave, and block the negative part of the AC signal, or, if they are reversed, they pass only the negative part and not the positive part.
A diode is the simplest possible semiconductor device, and is best device to learn and understand how a semiconductor works.
A transistor is a device made of a solid piece of semiconductor material and is used to amplify and switch electronic signals. A Transistor can be active in only One Direction and can draw more or less current through its load resistor.
A transistor is another good example of a semiconductor device.
Manufacturing semiconductors need expertise and experience. Manufacturing has to be done in a cleanroom environment. Chemicals to be used need to be pure and free from any impurity. The process of adding controlled impurities to a semiconductor is known as doping.
Steps involved in manufacturing semiconductors
- Design / Mask Creation
- Wafer Fabrication
- Device Formation / Device Insulation Layer Formation
- Device Formation / Transistor Formation
- Assembly and Testing
The semiconductors industry is over $300 billion as of today and is expected to grow @ 13-15% annually. USA, South Korea, Japan, and European Union dominate the industry and the business.
Top 10 Semiconductor Companies
Here is a list of top 10 semiconductor companies in the world:
- Intel Corporation: The world leader in silicon innovation, develops processor technologies and supports global initiatives.
- Samsung Electronics: Semiconductors including DRAM, Flash, SRAM, Graphics Memory, MCP, Mask ROM, System LSI, TFT LCD Modules and more.
- Toshiba: Manufacturer and supplier of Semiconductors, Memory Storage Device, General-Purpose Logic IC, Transistors, Diode, Optical Device, Sensor, Radio-Frequency Device, Microcomputer, ASIC, ASSP, General-Purpose Linear IC, Power Supply IC, Transistor Array, Motor Driver, Operational Amplifier IC, Comparator IC, Op Amp and other SMD Electronic Components.
- Texas Instruments: Designer and supplier of digital signal processors, discrete and integrated circuits, calculators, and digital light processing (DLP).
- STMicroelectronics: Offers System-on-Chip (SoC) and other such solutions.
- Qualcomm: Leading provider of advanced semiconductors manufacturing technology.
- Hynix (Formerly Hyundai Electronics): Manufacturer and supplier of dynamic random access memory (‘DRAM’) chips and flash memory chips.
- Renesas Technology: Semiconductors, microcomputers, logic and analog devices, discrete devices and memory products.
- AMD: Advanced Micro Devices: American multinational company.
Because of rapid growth in the industry, more and more semiconductor companies are coming up. There is great job and employment opportunity of electronics engineers in this industry.
Jobs are available in following categories:
- Electrical Engineering
- Software Engineering/DSP
- Technology Support
- Applications Engineering
- Materials Management
- Quality Assurance
Just explore the “career”, “jobs” or “work with us” section of the websites of these companies and apply for the best suitable job.
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