We hear a lot these days about the semiconductor crisis and how it directly affects our lives. But I think the main point is: what really is a semiconductor and how are they made? Hey engineering lovers, my name is Gustavo Pereira and today I'm going to tell you a little bit about semiconductors.
Semiconductors are a critical part of almost all modern electronic devices . Every type of electronics today has a semiconductor. From your cell phone, notebook, solar panels and even your car, it uses a variety of semiconductors.
But after all, what is a semiconductor? Semiconductors are solids capable of changing their condition from insulators to conductors with great ease. Semiconductors are solids that are normally crystalline and have variable electrical conductivity.
The term semiconductor can already say a little about them, as they are devices that are on the edge of conductivity, and can vary between being electrical insulators or electrical conductors depending on some parameters. Some semiconductors can act in such a way that when at low temperatures, they act as electrical insulators, that is, they do not conduct electricity, and when subjected to high temperatures, they conduct electricity. Depending on their electrical state, which may be positive, neutral or negative, they may or may not conduct electricity and with this function, it gains space and importance in the manufacture of electronic components such as diodes, transistors and more complex components such as microprocessors and even nano circuits.
. Generally speaking, the term semiconductor refers to a material like silicon that can conduct electricity much better than an insulator like glass, but not as well as metals like copper or aluminum. But today, when we talk about semiconductors, it is common to think about semiconductor chips used in electronic components.
These chips are typically made of thin slices of silicon with complex components placed on them in specific patterns. These patterns control the flow of current using electrical switches, called transistors. It works the same way you control the light bulb in your house, only it controls the switch electrically.
The difference between your house and a semiconductor chip is that semiconductor chips are entirely electrical with no mechanical components, meaning you don't have to click on anything. And a chip can contain tens of billions of switches in an area not much larger than the size of a fingernail. Perhaps you might think that semiconductors bear a resemblance to contact relays, after all, they control the passage of energy electrically.
However, contact relays are electrically controlled, but they use mechanical parts for this, since semiconductors are fully electric and do not have mechanical parts. But what do semiconductors do? Semiconductors are like the electronic devices that process, store and receive information.
For example, memory chips store data and software as binary code, digital chips manipulate data based on software instructions, and wireless chips receive data from high-frequency radio transmitters and convert it into electrical signals. These different chips work together under the control of the software. Different software applications perform very different tasks, but they all work by switching the transistors that control the current.
That is, today's software basically works by controlling transistors that turn switches on or off to perform certain tasks. The binary code we know with zeros and ones basically controls whether a system should turn on or off depending on some command. And how is a semiconductor chip built?
The starting point for the vast majority of semiconductors is a thin slice of silicon called a wafer. Today's wafers are the size of dinner plates and cut from single silicon crystals, much like this screen shot. Manufacturers add elements such as phosphorus and boron in a thin layer to the surface of the silicon to increase the chip's conductivity.
It is in this surface layer where transistor switches are made. Transistors are built by adding thin layers of conductive metals, insulators, and more silicon to this entire wafer disk. They assemble patterns into these layers using a complicated process called lithography , and then selectively removing these layers using computer-controlled plasmas of highly reactive gases to leave specific patterns and structures.
Because transistors are so small, it is much easier to layer materials and then carefully remove unwanted material than to place microscopically thin lines of metal or insulators directly on the chip. By inserting, patterning and etching layers of different materials dozens of times, semiconductor manufacturers can create chips with tens of billions of transistors per square inch. That is, inside that disk, we can have billions of switches that turn on and off in every square centimeter of that disk.
And why are today's semiconductors so different from the old ones? There are many differences, but the most important is probably the increase in the number of transistors per chip. Among the first commercial applications for semiconductor chips were the famous pocket calculators, which became widely available in the 1970s.
These early chips contained a few thousand transistors. In 1989, Intel introduced the first semiconductors to exceed one million transistors on a single chip. Today, the largest chips contain more than 50 billion transistors.
This trend is described by what is known as Moore's law, which says that the number of transistors on a chip will double approximately every 18 months. As we can see in the on-screen graph, the number of transistors in a microprocessor grew exponentially in the mid-2000s . Moore's law held true for five decades.
But in recent years, the semiconductor industry has had to overcome major challenges, mainly in how to keep shrinking the size of transistors and continue at this pace of advancement. One solution was to switch from flat, two-dimensional layers to three-dimensional layers. 3D chips have significantly increased the number of transistors on a chip and are now in widespread use, but they are also much more difficult to make.
And of course, with technology like that, you would expect to need factories and very advanced technology to produce these chips. And yes, the more complicated a chip, the more embedded technology we have and consequently the more complicated their manufacturing process and also, much more expensive. There was a time when almost every semiconductor company in the US built and maintained its own factories.
But today, a new foundry can cost upwards of $10 billion just to build. Only the biggest companies can afford this type of investment. Instead, most semiconductor companies send their designs to independent foundries for manufacturing.
The “Taiwan Semiconductor Manufacturing Co. ” and New York-based Global Foundries are two examples of multinational foundries building chips for other companies. They have the expertise and especially the money to invest in this kind of cutting-edge technology .
Ironically, while the transistor and semiconductor chip were invented in the US, no state-of-the-art semiconductor foundries are currently on American soil. The US was once semiconductor foundries in the 1980s, when there were concerns that Japan would dominate the global memory business. But today, most semiconductors are smelted in Taiwan.
Okay, but why are we experiencing a semiconductor crisis? As I already said, the vast majority of semiconductors are smelted in Taiwan and the second largest number of semiconductor smelters is China. In other words, the manufacture of these semiconductors is concentrated in just two countries, and they supply the whole world.
If you follow the news, you know that the relationship between Taiwan and China ends up generating some concern of a possible conflict. Should there be a war between the two, the world could experience a semiconductor shortage that would have a global impact. To give you an idea, this concern led the US government to pass the Chips and Science Act, which will deal with the science and creation of chips and try to bring the manufacturing and smelting of state-of-the-art semiconductors to the United States, breaking a little this monopoly of two countries.
This law will generate a subsidy to boost the production of semiconductors in the United States with almost 50 billion dollars of investment. In addition to a possible war, we also had the covid-19, which slowed down the production of semiconductors with the restrictions imposed. In other words, we had a crisis with the low production of semiconductors in the world because of covid, and now we can suffer from an even greater drop if the two countries come into conflict.
And you, what do you think of this semiconductor crisis? What if Brazil started to invest in this technology on Brazilian soil so that we could produce our own semiconductors? Do you think we made it?
Leave it here in the comments. I'll leave two videos here that you might like too, so click on one of them to check it out. Don't forget to like the video, subscribe to the channel and activate the notification bell.
That's it my friends, a big hug and see you in the next video.
