Semiconductor 101: What is a Semiconductor and How are they Useful?

Semiconductors help expand what is possible in the world, electronically.  Our world is literally controlled in many aspects by semiconductors.  From our computers and phones to solar panels, cameras, military devices, and a host of medical equipment, semiconductors are everywhere.  Have you ever wondered what exactly a semiconductor is or how they work? 

Semiconductors are unique materials in the way that they conduct electricity and are an essential component of electronic devices.  With electronics, there are three groups of material types.

  1. Conductors are materials that electricity readily passes through.
  2. Insulators on the other hand do not allow electric currents to flow. 
  3. Semiconductors are special in the way that they allow an electric current to travel through as their temperature rises.

In a recent interview, Angela Thurman defined Semiconductors, “A semiconductor is a material whose resistivity (or the property of a material to resist the flow of electrical current) is between 10-3 and 106 ohm-cm.”

Examples of Semiconductor Materials

Two natural semiconductor materials are silicon and germanium, both of which are elements.  Beyond these two elements, some compounds are also semiconductors including: Silicon Carbide (SiC), Germanium Arsenide (GeAs), Gallium Arsenide (GaAs), and more.

What Makes Silicon and Germanium Good Semiconductors?

The simplistic answer to the physical properties that make silicon and germanium good semiconductors has to do with their atomic structure.  Specifically, the electrons in their outer valence shell create semiconductive properties.  Atoms are either attracted or not to other atoms based on the electrons in the outer valence shell.

As we mentioned, compounds including SiC, GeAs, and GaAs are semiconductors.  These materials are crystalline, inorganic solids.  It is the electrons in their outer valence shells that create their semiconductor properties.  The electrons from the separate atoms bond together to form covalent bonds that combine to create the semiconductive crystals.

Silicon is an Abundant Natural Resource

Silicon is by far the most widely used semiconductor material, due to the fact that it is widely available, easy to fabricate, and has excellent electrical and mechanical properties. Silicon is the second most abundant element on Earth after Oxygen. But nearly 80% of the world’s Silicon stores are controlled by China.

Crystals are the Key to Semiconductive Compounds

Even though Silicon is abundant, it has to be mined and extricated from the surrounding material before it can be processed into a semiconductor wafer.  Since China controls so much of the Silicon market, the current restrictions have made it very difficult for the foundries to obtain the raw material they need.

The Important Role of a Foundry

Regardless of whether the semiconductor is Silicon, Germanium or some compound, to be used for integrated circuits that go into the goods that we all want, these semiconductor materials must be very highly purified, typically through the growth of new crystals from crushed material that is melted down in a foundry.

What is a Foundry you might be thinking?  A foundry is a plant where metal is processed.  According to Reliance Foundry, “a foundry is a factory where castings are produced by melting metal, pouring liquid metal into a mold, then allowing it to solidify.”

A 2020 report listed these as the Top 10 Semiconductor Foundries:

  1. Taiwan Semiconductor Manufacturing Company – Taiwan
  2. Samsung Electronics – South Korea
  3. GlobalFoundries – USA
  4. United Microelectronics Corporation – Taiwan
  5. Semiconductor Manufacturing International Corporation – China
  6. Tower Semiconductor – Israel and USA
  7. Powerchip Technology Corporation- China
  8. Vanguard International Semiconductor Corporation – Taiwan
  9. Hua Hong Semi – China
  10. DB HiTek Co., Ltd – South Korea

What is a Semiconductor Wafer?

Wondering what a Semiconductive Wafer is?  According to EasyTechJunkie, “Semiconductor wafers are 4 to 10 inches (10.16 to 25.4 cm) in diameter round disks that carry extrinsic semiconductors during manufacture. They are the temporary form of positive (P)-type semiconductors or negative (N)-type semiconductors.”

If foundries cannot get the raw material that they need, production of the wafers slows down or comes to a stop.  That means no more integrated circuits, printed circuit boards, power supplies, etc.  And that means that the production of the electronics business as we know it eventually is impacted.

Semiconductors are Extremely Important to the Global Economy

According to the Semiconductor Industry Association (SIA) “Semiconductors are the brains of modern electronics, enabling technologies critical to U.S. economic growth, national security, and global competitiveness.

Semiconductors have driven advances in communications, computing, health care, military systems, transportation, clean energy, and countless other applications. And they are giving rise to new technologies that hold the promise to transform society for the better, including brain-inspired computing, virtual reality, the Internet of Things, energy-efficient sensing, automated devices, robotics, and artificial intelligence. Semiconductors’ greatest potential lies ahead.”

Needless to say, modern technology wouldn’t be nearly as advanced if it weren’t for semiconductors and the way they help control the flow of electrical currents.

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