Have you heard about semiconductors? Probably yes. But do you know anything about them? Like most people, no!
Don’t worry, this article intends to change that. Consider this an introduction to the RENA Technologies GmbH world of semiconductors. By the time you finish reading the document, you’ll be in a position to confidently discuss the subject.
So, what is a Semiconductor?
When you play your charger into a socket, how does it work? Electricity travels from the socket through a copper wire in your charger till it reaches your phone. The setup works perfectly because the copper wire inside the charger is a good conductor of electricity. It transfers electric current well under any conditions. Copper and other conductors like aluminum and steel allow current to pass with little or no resistance at all.
Unlike conductors, semiconductors act as insulators most of the time. They have high resistance to current and don’t transmit current easily or at all. On the spectrum are insulators that don’t conduct electric current at all. In most cases, insulators are used to prevent power from arching out of the conductors resulting in harm and injuries.
Therefore, a semiconductor is a physical substance that’s designed to control and manage the flow of electric current in devices and equipment. Put simply, it doesn’t allow a free-flowing current or repels it completely.
A semiconductor sits between an insulator and a good conductor. It is used in the manufacture of computing components, devices, and electronic chips.
Semiconductors are created from pure elements like germanium or silicon. In that process, impurities are added to the pure item. The inductance or conductance of the semiconductor is dependent on the impurities added.
The Types of Semiconductors
There are two types of semiconductors. A P-type semiconductor that’s used when the inductance is high and free electrons are few. The N-type is used when the conductance is higher and the free electrons are many.
The P-type and N-type semiconductors aren’t great by themselves; but when put together, you get an interesting behavior at the junction.
The devices and components built using a semiconductor include diodes, computer memory, transistors, and integrated memory.
The Elements Used to Create Semiconductors
Let’s take a closer look at the pure elements used to create several semiconductors.
The chemical is similar in appearance to silicon. Due to its reactivity factor, it is not found as a free element in nature.
Germanium is available in the earth’s crust and is mined from sphalerite zinc ores. It can also be extracted from copper ores and fly ash coal.
The high cost and thermal sensitivity of germanium make it less useful than silicon. However, it can be alloyed with silicon for usage in high-speed devices.
Silicon makes over 25 percent of the earth’s crust by weight. It is also the second most abundant material on the planet. And yes, it is not found as a free element but as oxides and silicates like flint, opal, sand, quartz, amethyst, agate, citrine, among others,
To get silicon metal, a reaction between silicon oxides and carbon materials like wood chips and coal takes place.
How Do Semiconductors Work?
Semiconductors have a huge impact on our lives and society. Yes, semiconductors are the heart of transistors and microprocessor chips. Anything that uses radio waves or is computerized depends on semiconductors to function.
And yes, most transistors and semiconductor chips are created with silicon. Have you heard of expressions like “Silicon Valley” or “Silicon Economy?” That’s because silicon is the heart of every electronic device.
1. A Diode
It is the simplest semiconductor device. It is a starting point for those who want to know how a semiconductor works.
A diode allows electric current to flow in one direction. Have you seen turnstiles in subway stations that only allow people to go in one direction? That’s how a diode works.
But how does this happen?
Yes, the N-type and P-type silicon are conductors by themselves, how come when they’re put together in a diode current flows in one direction? Well, that’s because the N-type silicon is attracted to the negative terminal while the P-type is attracted to the positive terminal. At the junction, the electrons are moving in the opposite direction and thus no current passes through.
So in simple terms, a diode is any device that lets current flow in one direction while blocking flow in another direction. Diodes are important in various ways. For instance, an electronic device that uses direct current will have a diode to protect its intricate parts if the batteries are inserted backward.
Unlike the two layers used in a diode, a transistor uses three layers. For instance, one can use a PNP or an NPN sandwich.
A transistor may act as an amplifier or a switch. From the arrangement, a transistor looks like two diodes back to back. And yes, the two diodes will block the current both ways.
However, if a small current is applied to the center layer, a larger current flows through the sandwich as a whole. This is what gives the transistor a switching behavior.
A silicon chip is capable of holding thousands of transistors. Since they act as switches, one can create Boolean gates that make it easier to develop microprocessor chips.
This natural progression from silicon to microprocessor chips is what makes electronic devices ubiquitous and inexpensive in today’s society. Through constant refinement of these points, it’s now possible to have millions of transistors in a single chip. Amazing, right?
A semiconductor is a material whose conductivity properties lie between insulators and conductors. Under certain conditions, they can act as either conductors or insulators. And yes, after creating a PN junction, a semiconductor can control the direction of flow of electrical charges which is not possible with conductors that allow current to flow in both directions.
Due to these properties, semiconductors are revolutionizing the electronics industry. Some semiconductor components like diodes allow the flow of current in one direction thus acting as a one-way electronic valve.