Semiconductors: Everything You Need to Know

What Is Semiconductor?

The semiconductor is a material that is neither a good conductor nor a good insulator but a material that conducts more electricity when heat, light, or voltage is added. As far as the available solid crystalline substances are concerned, the ones such as germanium or silicon,  have electrical conductivity greater than insulators but less than good conductors. And they form the base for computer chips and other electronic devices.

History Of Semiconductor

The transistor, the first real semiconductor device, was invented in 1948 at Bell Laboratories. The commercial semiconductor industry began in earnest in the early 1960s and surpassed $1 billion USD in annual revenue for the first time in 1964. Gordon Moore was a semiconductor researcher and also the co-founder of the Intel Corporation, the world’s largest semiconductor device producer, who developed a groundbreaking theory in 1965. He famously predicted that developments in semiconductor technology would allow producers to double the number of transistors they included per electric circuit every year. The effect of this would be that they would drastically increase the speed and functionality of each processor. While Moore later amended this forecast, it proved to be a remarkably accurate insight into the remarkable rates of growth that would be seen in this industry. Processors, a form of integrated electric circuits, were able to hold only 2,300 transistors in 1971. By 1982, processors were capable of containing 134 thousand transistors. In 2004, that number had increased to 592 million individual transistors. These increases have had an enormous impact on the efficiency of modern computing and, more generally, technology as a whole. Behind these trends, the semiconductor industry, first in the United States and later globally, has had a huge role to play in how we are able to use and interact with technology. As our credence on technology grows, so will our dependence upon the semiconductor industry.

Types Of Semiconductor

There are two types of semiconductors.

• Intrinsic Semiconductors
• Extrinsic Semiconductors

1. Intrinsic Semiconductors

A natural semiconductor that does not consist of impurities is called an intrinsic semiconductor. A semiconductor can be termed an intrinsic semiconductor if it consists of natural elements i.e pure elements. The conduction band of the intrinsic semiconductor contains as many electrons as there are holes. In this type of semiconductor, the valence electrons can jump across the conduction band using very small energy i.e the energy that can be generated at room temperature. This scenario results due to the presence of a very small forbidden energy gap.

2. Extrinsic Semiconductors

In general, semiconductors possess poor conductivity, hence to increase this conductivity controlled addition of impurities to the intrinsic semiconductors is preferred. The process of adding such impurity is called doping which then increases the current carrying capacity of the semiconductor.

 The two types of impurities are N-Type and P-Type.

• N-Type Semiconductor :

In an N-type semiconductor the current is due to the electrons since an atom containing five valence electrons is added to the intrinsic semiconductor, where the four electrons are used for the formation of covalent bonds and one electron remains free.

• P-Type Semiconductor :

In a p-type semiconductor, the current is due to the holes since an atom containing three valence electrons is added to the intrinsic semiconductor, where all three electrons are used for the formation of covalent bonds and the resultant hole is due to the absence of a fourth electron.

Application of semiconductors in daily life

• Semiconductors are used in solar technology
• Used in 3D printing machines
• Air conditioners use temperature sensors that are made with semiconductor devices.
• Semiconductors are used in rice cookers as they control temperature precisely thereby allowing the cooker to cook properly.
• Semiconductors play a central role in the operation of bank ATMs, trains, the internet, communications, and other parts of the social infrastructure, such as the medical network used for the care of the elderly, among other things.
• Used in self-driving cars
• Computers, calculators, solar plates, and other electronic devices have semiconductors in them.

Microchips used in our electronic devices such as computers, mobile, etc. also use semiconductors.

Advantages Of Semiconductors

• Filament heating is not required in semiconductors so device such as transistor takes place in almost all vacuum tube applications. Because the filament vacuum tube requires heat for operation.
• Semiconductor devices are shockproof because they are solid-state
• Semiconductor devices are portable as they are so small in size
• It is cheaper than a vacuum
• Operations in semiconductor devices require less input
• It does not make any noise during the operation period. Hence semiconductor devices are noise-free devices.
• Semiconductor materials have a longer lifespan.

Which Devices Are Made With Semiconductors?

Semiconductors are useful in manufacturing very small electronic devices that have the potential to evolve modern electronics.

1. Two terminal devices :

• Diode – which is made up of two semiconductors. It is made with a p-n junction. The diode only passes current through it when it is in forwarding bias. Diodes are used in rectifier circuits that convert A.C to D.C.
• Gunn diode
• IMPATT diode
• Laser diode
• Zener diode
• Schottky diode
• PIN diode
• Tunnel diode
• Light-emitting diode (LED)
• Phototransistor
• Photocell
• Solar cell
• Transient-voltage-suppression diode
• VCSEL

2. Three-terminal devices :

• Field-effect transistor
• Darlington transistor
• IGBT
• Unijunction transistor
• Silicon-controlled rectifier
• Thyristor
• TRIAC

3. Four-terminal devices :

• Photocoupler (Optocoupler)
• Hall effect sensor (magnetic field sensor)

Semiconductor Industry

Worth over $300 billion USD today, this high-tech industry has grown to immense levels since its inception less than 70 years ago.

China is the world’s largest silicon producer, with a production volume estimated at four million metric tons in 2018. The second largest producer of this metalloid in the world is Russia, which produced 670,000 metric tons in the same year. In totality global production of silicon in 2018 was around 6.7 million metric tons.

Semiconductors are undoubtedly among the most essential building blocks of our modern way of life. They are materials that are used, due to the way they interact with electricity, in the flow and control of electric currents. Semiconductors are used in semiconductor devices to control the flow of electricity, and part of essentially every electric device used in the world today. These devices, primarily transistors, have replaced vacuum tube technology as the primary means of manipulating the flow of electricity within electric circuits. They have drastically increased the efficiency of this process over the past several decades, and transistors have gotten ever smaller, allowing for the devices they are used in to be reduced in size as well. Because of this technology’s own successes and universality, the industry has undergone one of the most remarkable periods of growth of any product in history. The global semiconductor industry is now over $300 billion USD and represents one of the most important technological sectors on the planet.

The United States yields more than half of the world’s semiconductor production. Silicon Valley which is the greatest technology hub in the US is named after the element that is one of the most common in semiconductors. This is a testament to how important the use of semiconductors and transistors has been in the development of the use of technology in the United States. While Silicon Valley is more broadly a technological center, the state of California as a whole contains the vast majority of the country’s semiconductor production capacities. South Korea and Japan are indeed the other two dominant countries in the world in terms of semiconductor production. The demand for semiconductors is driven by the desire of consumers to purchase all forms of modern electronics. Semiconductors are used in essentially all electronics, from computers and cars to phones and lighting systems. This means that regardless of whether a device may be in or out of fashion at a given time, the overall trend in technological advances and the resulting demand continue to drive the sale of this industry’s products. The growth in the use of technology in the developing world is one of the major trends relevant to the semiconductor industry’s continued expansion. While the Americas have traditionally been the dominant destination for technological goods, and therefore semiconductor devices, Asia is now by far the world’s largest market in this arena.

Research and development (R&D) represent an unusually high portion of the semiconductor industry relative to other sectors. The rapid change of pace in the industry demands that companies therein must actively pursue more efficient technologies, and commit large portions of their budgets to R&D. The advances in this industry are responsible for a significant portion of both the technological and economic efficiencies that have been achieved during the Information Revolution. As a result of their nature, any explanation of the actual production of semiconductor devices tends to be highly technical.  To either create individual semiconductor devices like transistors or larger circuits such as computer processors, chemical processes employ semiconductor materials like silicon. These are then sold to manufacturers that use these components in the development of their individual consumer technologies, such as personal computers and smartphones.