When you make computer chips, they use Silicon. What is Silicon, and why?
Many people might think it’s a silly question that can be answered in a few words. When you look at a periodic table, Silicon is the 14th thing. Many things in the universe are made up of it. It’s one proton heavier than aluminum and one proton lighter than phosphorus. On the other hand, Silicon comes up more often than almost any other element on a site like ExtremeTech. It’s a big part of the building materials that make up your home, it’s the basis for all current computer processors, and it’s even the most likely source of non-carbon-based life outside of Earth. Exactly what makes Silicon so unique?
Silicon is a building block that can be used.
Silicon is one of the unique things because there is a lot of it. If you look at the Earth’s crust, it has a lot of it after oxygen. But don’t expect to find it all over the place. Silicon is rarely found on its own. Instead, it almost always comes in a mixture of other things. A silicate, which is one silicon atom bound to four oxygen atoms, is the most common form. Silica, another type of silicate, isn’t very common (SiO2, or one silicon atom bound to two oxygen atoms). In a rough and dirty form, silica is the main ingredient in the sand. Many different things made up of Silicon and oxygen are called feldspar, granite, quartz, and more.
Mix this with water and gravel, and you’ll have a concrete mix.
Most of the time, silicon compounds have a lot of good qualities because they can hold other atoms together very well and in very complicated ways. Some silicates, like calcium silicate, are important parts of Portland cement, which is used to make concrete, mortar, and even stucco. Most of the world’s glass is made of soda-lime glass. Some silicate-rich materials can be heated and turned into ceramics that are hard like porcelain, while others fuse to make soda-lime glass. If you want to make something more durable, you can add a small amount of Silicon. For example, you can add a small amount of Silicon to cast iron to make the iron more durable.
As you know, Silicon is also a big part of the synthetic material silicone, but don’t mix them up – if Silicone Valley were a real place, the tech world would be very different than it is now.
The computer chip is made out of Silicon, which is made out of Silicon.
The most important thing to look for when making a computer transistor is resistance. Electric current moves very quickly through conductors. On the other hand, insulators slow down or stop the flow of electrons. We need a semiconductor to make a transistor that can be turned on and off at will. It needs to be able to switch on and off at will. The best semiconductors for the industry can be treated with a wide range of “dopants” to make them have the right resistance.
An ingot is a piece of pure Silicon.
Silicon isn’t the only thing on Earth that can be used as a semiconductor. It’s not even the best semiconductor on Earth. Because of how many there are, it is far and away from the most common semiconductor on Earth. Silicon is available worldwide, so you don’t need to get it from special African mines or spend a lot of money and time treating it to get some. It’s easy to work with, and, most importantly, scientists have found a way to grow it into perfectly aligned crystals. Diamond is made of carbon, and these crystals are made of silicon and carbon.
One of the most important skills in modern computer chips is growing huge, almost-perfect silicon crystals. Some of these crystals are cut into small pieces and thin wafers. They are then engraved, processed, and treated differently before being cut into individual dies and put into commercial processors. Things like carbon can be used to make better transistors, but they can’t be used in the same way that Silicon can be used to make many transistors simultaneously.
SiO2 crystals, called “ingots,” are currently made in 300 mm diameter cylinders. But research is quickly approaching the point where it can make them in 450 mm cylinders. Production costs should stay low, keeping speed going up for at least another decade or so. Then what? There may be no choice but to stop using Silicon and start using something less abundant and easier to work with. This is good news for processing speeds, but it’s almost certain that it will be bad news for your bank account.
It’s the same thing as having alien life.
There is a lot of talk about “carbon-based life.” What does it mean? In other words, the main structural molecules that make up our bodies, like proteins and amino acids, and nucleic acids, are made up of carbon atoms. To be clear, that’s because carbon is very good at being “tetravalent.” Oxygen and nitrogen can only form two stable chemical bonds, which leads to water or H2O. On the other hand, carbon can hold onto up to four different atoms at once (thus giving us methane or CH4). Because tetravalency is a strong foundation for building strong and geometrically complex molecules, it has helped all life on Earth, and other planets revolve.
Star Trek’s Horta is thought to be made of Silicon.
Even though we know how the Periodic Table is put together, we still don’t know how carbon and Silicon differ. We know that elements in a vertical column have the same chemical properties. This is why science fiction writers have spent so much time and money on the idea of silicon-based life. Because Silicon is tetravalent, it is the most likely alternative structural element for new kinds of life. There are a lot of items that Silicon can do to make strong bonds with other silicon atoms like carbon does with carbon. This means it can double-lock certain shapes into place. Both are thought to be important for life to grow.
Silicon is a lot more common on Earth than carbon, so there must be a reason why we’re organic (carbon-based) instead of silicon-based. That reason comes from the Periodic Table. Without much detail, elements closer to the bottom of the Periodic Table have heavier nuclei and bigger electron shells. For example, Silicon is bigger and heavier than carbon, making it less suitable for tasks like recombinant DNA. Silicon is also less reactive than carbon, which means that silicon-based life might be less chemically diverse, or it might need a lot more reaction-driving silicon enzymes to make less-desirable compounds.
Life on Earth is all organic, even though silicon atoms outnumber carbon atoms almost 1,000 to one. This could show how likely it is to happen elsewhere in the universe. Several species here use Silicon somehow, but none of them use it to make DNA. Life made of Silicon isn’t impossible, but there’s a good chance it won’t be able to get to the level of complexity that carbon has here on Earth.
It’s made of Silicon, and you can use it
This word will keep coming up in your news feed for a long time even though some people are looking at carbon and other non-silicon elements as the platform for next-generation computing, which will be necessary if we want to keep up with the exponential growth in computing power that we’ve seen in the past. In many fields, Silicon is still the material of choice. We will be able to develop new and exciting ways to control how it treats electrons, Perhaps.
Will we find that it is the source of all life in the universe, except that which came from Earth? No, but it could happen. For one thing, silicon compounds make up most of the rock that makes up most of the Earth’s crust.
Even though we might be leaving Silicon behind, it was also possible to do so 20 years ago. In most cases, it will keep being one of the most important things for humans to learn about the physical world.