Right now, silicon is in every chip, what about tomorrow?

01.03.2023 82 0

During the ’50s, the tech world found a reliable component, the silicon. In 1958, the first computer chip using silicon was produced and that meant a revolution for the computer industry.

Thanks to silicon, instead of having room-sized computers, we have laptops and smartphones that we can take everywhere. This material was the reason to leave behind the old circuit design, miniaturize it, and make it faster, more powerful, and much more affordable for everybody.

Yes, the development of the integrated circuit (IC) improved the situation by setting the different electronic circuits of a computer on little boards called “chips”. IC left behind the old and fragile vacuum tubes, and reduced the size of computers, allowing for their mass production.

You might also like this article: “The history of the computer mouse”.

What is silicon?

In the periodic table, this chemical element belongs to the carbon group, which includes carbon, germanium, tin, lead, and flerovium. Identified as “Si”, it is the eighth-most abundant element in the universe by its weight. And if we just talk about our planet, 28.2% of the Earth’s crust contains silicon. So still there is massive storage of the material “at home!”.

Silicon is a metalloid, so it has some metal features, yet, it is not a true metal. It is a good semiconductor so it allows electricity to pass through, but you can easily control the flow unlike with metals.

In other words, a metal conducts electrons by nature and it is hard to turn this property off, according to different needs. An insulator material just like plastic or wood doesn’t allow electricity to pass through them. Meanwhile, a semiconductor allows electricity to pass while working as an insulator at the same time.

Other silicon advantages

  • It is a versatile material. Silicon can be combined with other elements to give birth to a variety of compounds, like the popular silica (silicon dioxide), which is a common component of glass and ceramics.
  • Silicon has a high melting point of 1414°C. This makes it a useful material for high-temperature applications.
  • High thermal conductivity. Silicon is a good conductor of heat, making it useful for heat sinks and other heat-dissipating applications.
  • Affordability. Silicon is quite affordable thanks to its abundance and is not that hard to purify.
  • It works well at a wide range of temperatures. Besides, you can modify it chemically to change its electrical properties. This way, it will address as much electricity as you need.

This makes it possible, for instance, to pass from “off” to “on” mode, and vice-versa, at normal temperature, or to let electricity pass through certain transistors selectively, without burning the circuits. Moreover, you can use just one material to design plenty of different components in the same device.

Why is silicon used for computer chips?

Silicon is used for computer chips because it is a very good semiconductor material. It can be used to create transistors, which are essential for building electronic circuits. Transistors are tiny electronic switches that can be turned on or off, and they are used to amplify or switch electronic signals. Basically,  transistors are the building blocks of computer chips.

Silicon is particularly well-suited for use in transistors because of its high melting point. It means silicon is stable and resistant to heat which is essential for transistors because they produce a lot of heat when they are in use, and it is key to keep the temperature of the chips low to prevent them from malfunctioning.

It is a good conductor of electricity and transistors rely on the flow of electrons to work properly. Silicon’s conductive features allow it to efficiently carry the electrical signals that are used to control the transistors. Rephrasing a bit, the extra small transistors in our Central Processing Units (CPUs) need insulated areas to control and direct the flow of electricity precisely.

And last but not least, silicon’s abundance and price have strongly positioned it as a viable material to be used in the industrial production of computer chips.

Where does silicon for chips come from?

Silicon is a chemical element that is found naturally in different sources, including sand, quartz, rock, and other minerals.

The extraction of silicon from these minerals is done through silicon refining. This process involves heating the minerals to very high temperatures to extract the silicon. The resulting silicon is then purified and processed further to produce the high-purity silicon that is required in computer chip manufacturing.

The production of computer chips demands a high level of cleanliness and precision. Silicon refining usually takes place in specialized facilities called silicon refineries. These are frequently located near rich sources of silicon (minerals) and in remote places to prevent contamination risks.

Heating minerals is a common technique for the extraction and purification of silicon. The use of chemicals to dissolve impurities and specialized equipment to clean silicon of contaminants is also popular.

The silicon specifically required by the chip’s production industry comes in thin wafers that later on become chips themselves. Wafers are thin pieces of semiconductor material, silicon crystal, in this case. They come in a variety of purity levels and sizes. Wafers are exactly what is needed to manufacture integrated circuits (ICs) and more micro-devices.

Which countries are the top producers of silicon for chips?

The top producers of silicon for chips are China, the United States, and presumably Russia. This last has been constantly ranked as a top silicon producer, but due to the current conflict that started in February 2022, no updated information allows us to confirm this position. Generally, these countries oversee the majority of the world’s silicon production, and they have large, modern facilities that are capable of producing high-purity silicon on a large scale.

Other important producers of silicon for chips are Brazil, Norway, France, Germany, France, Canada, and Malaysia.

It’s worth noting that the ranking can change from year to year based on different factors, like geopolitics, changes in demand, modifications in the price of silicon, and technological advances that help improve production methods.

Is there a shortage of silicon?

Confusion has arisen about a shortage of silicon to produce chips. There is indeed a shortage of chips produced with silicon, but it has been caused by different factors. And until the moment this article is being written, there is no news pointing out the shortage of the material itself. Let’s go deeper into the domino effect that led the world to this situation.

There was a combination of factors that originated the silicon chip shortage. We all knew about it in 2020, the year when the COVID-19 pandemic hit the whole world. COVID-19 strongly affected the supply chain. Some companies were forced to completely shut down or they needed to implement measures to protect employees at the cost of slowing down their production. Everything, from the refining of silicon, silicon wafers production, obtaining the material to produce, computer chip manufacturing, and delivery of the final product was affected.

On the other hand, the demand for products containing chips was already huge and the pandemic context boosted it even more. Industries demanded more automation and computing systems. People were at home longer than in the past, so their needs changed too.

Another situation, of a very different nature, got added. Producers of silicon computer chips need a lot of water to make the material ready to be used. Taiwan, the number one producer of silicon computer chips, faced a drought. This affected their production pace and supply of the product to the world. The lesson is clear, without enough water this can happen again. And water is another deep topic to talk about.

Along with this, we are also running out of sand, one of the natural sources of silicon. The problem is that different industries strongly rely on the use of sand: construction, cosmetics, glass, and computer chip manufacturing. It is not a new problem, the sand shortage has been warned about at least a few years ago, but there are no signs of abating it. Nature needs time to replace this resource and it will never manage to do it as fast as it is exploited by these industries. Population growth, technology, energy use, fast urbanization, and consumption, demand billions of metric tons every year.

All these factors caused a shortage of chips produced with silicon. There are ongoing projects worldwide to solve it. But it will take at least two more years.

To summarize, strictly there is no shortage of silicon now, but a shortage of chips produced with silicon. Being such a highly demanded resource, it’s understandable if it is scarce in the future. Now, sand as a source of silicon is already a red flag. Keeping this rhythm, the situation can get more complex demanding longer, harder, and more expensive ways to extract the resource. Unfortunately, this possibility can’t be ruled out.

Can silicon be replaced by another material to produce computer chips?

Silicon’s advantages make it the choice for computer chip manufacturing. But crises like the described shortage and the everyday higher demand for more (number) and more powerful computer chips have pushed researchers and developers into alternative materials that could work for this purpose in the future.

Indium antimonide, molybdenum disulfide, and carbon nanotubes have been analyzed and their features have pointed them out as suitable for computer chip production. But still, they are not mentioned as definitive candidates to replace silicon.

Graphene has been tested too. It is a material composed of a single layer of carbon atoms arranged in a hexagonal lattice. Graphene has shown attractive features to be used in computer chips, like strength, high electrical conductivity, and flexibility. As drawbacks, its large-scale production, and costs to completely replace silicon in the computer chip industry are not clear, and not solved yet.

Recently, in July 2022, there was a report of a team of scientists (American and Chinese-born, now naturalized American), who found a much better semiconductor than silicon: cubic boron arsenide.

Cubic boron arsenide has been shown in experiments to have a thermal conductivity ten times better than silicon, so its heat dissipation emerges as a great. It allows high mobility for electrons and holes, while silicon, and other materials like Gallium arsenide offer good electron mobility but poor hole mobility. As a result of silicon not being the best conductor of heat, overheating issues are possible so powerful cooling systems are needed to prevent them. Yes, heat is a constant worry for many electronics, and it could be solved with cubic boron arsenide’s capabilities. Scientists are describing this discovery as a “gamechanger”. The challenge they face is how to mass produce the material, but still keeping its quality whilst making it economically viable.

The future of silicon – Conclusion

This material already has an important place in the history of tech advances, but the development hasn’t stopped. High-performance processors where electrons move even faster than in silicon are being designed.

On the other hand, transistors are made smaller every day to make chips more powerful and more power-efficient. Silicon will be useful to the point allowed by its chemical properties. To put this in context, now that companies use nanometer chips, silicon won’t be able to satisfy those needs and some other materials will be required.

Silicon’s presence in the computer chip industry will remain. The advantages of this material won’t be wasted by such a demanding industry.

Now, new combinations are emerging like the silicon carbide (SiC) or carborundum, a compound of silicon and carbon. It has three times higher thermal conductivity than silicon. Therefore, it is being used in power electronics and electric vehicles like Tesla ones.

By the way, if you are a fan of the electric vehicles, check this article: “Are there alternatives to the lithium-ion batteries?”.

The path from the vacuum tube-circuit design to the miniature-modern-transistor age was built with silicon, but technology evolves, and possibly, alternative materials get onto the scene. Let’s see how new materials or combinations will reshape future computer tech!

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