This article discusses semiconductors, the most commonly encountered of the many disciplines in electrical engineering. It covers why semiconductors are important devices because they are materials with properties that are intermediate between conductors and non-conductors, allowing them to control electrical conductivity. Through the addition of impurities, devices such as transistors can be made, which play a role in signal amplification and switching in electronics. Reliability research is essential to reduce defects such as traps in semiconductor manufacturing, and semiconductors are the foundation of advanced technologies such as AI, autonomous driving, and IoT.
When non-science majors first hear the name “Electrical Engineering,” the first thing that often comes to mind are topics like Samsung Electronics and semiconductors. In fact, the Department of Electrical Engineering covers a wide range of subjects beyond semiconductors, such as power systems, electronic circuit design, communication systems, and control engineering, but the public often only sees news such as “Samsung Electronics’ semiconductor division’s highest operating profit ever” in the media. In this article, I will focus on semiconductors, one of the many fields covered by electrical engineering that is of particular interest to the public. I will explain what semiconductors are, how they are made, and the defects that can occur in their production and the need for research.
Many people have heard the word ‘semiconductor’, but few know exactly what it means. In general, we all know about conductors and non-conductors, but to summarize, a conductor is an object that flows well with electric current, and a non-conductor is an object that flows very little. So what is a semiconductor? Taken literally, it is a material that flows ‘halfway’ through electric current. Typically, semiconductors are made using the element silicon (Si). Pure silicon is almost a non-conductor, meaning that very little current flows through it. However, certain impurities can be added to this silicon to regulate the flow of current. This is done by adding impurities that create “electrons” or “electron holes” in the structure of the silicon atoms, making the semiconductor intermediate between a conductor and a non-conductor.
Why go through all the trouble to make a semiconductor that doesn’t allow electricity to flow freely like a conductor? It’s because of semiconductors’ unique ability to control electrical conductivity. Electrical conductivity is a property that describes how well an object allows electricity to flow through it, and can be likened to the cross-sectional area of a waterway. Just as the wider the channel, the faster the water flows, the higher the electrical conductivity, the better the current flows. Semiconductors have the freedom to control the width of this channel, or electrical conductivity, by controlling the type and amount of impurities. For example, there are p-type semiconductors and n-type semiconductors, where p-type semiconductors are characterized by the movement of holes (holes) with a positive charge, and n-type semiconductors are characterized by the movement of electrons with a negative charge. These two types of semiconductors can be combined to make basic devices, such as diodes, that control the flow of current.
These semiconductors can be used to make the most basic electronic device, the transistor. Transistors have the ability to open and close pathways for current to flow through them, which allows them to amplify or switch electrical signals. With current technology, these transistors can be made very small, on the order of tens of nanometers (nm). Billions of transistors are packed into small devices like smartphones to enable high-speed computation. This microscopic size and the ability to efficiently control the flow of electrical signals makes transistors a key element in many electronic devices and computers.
However, the semiconductor manufacturing process can introduce a number of defects. In particular, defects called traps occur within semiconductors, which means that some of the billions of transistors do not work as intended, greatly affecting the reliability of the semiconductor device. Traps are like tiny holes in a waterway. If you’re trying to get a steady flow of water, drop by drop, and there’s a hole in the middle of the channel, the water won’t flow properly and will interfere with the normal operation of the device. This in turn reduces the reliability of the electronic device and, in severe cases, can lead to failure.
Reliability studies are needed to solve the problems caused by traps. In electrical engineering, these studies are used to find the location and cause of traps and develop techniques to reduce them in the manufacturing process. Reducing defects in semiconductors is a critical task, especially in the current era when many electronic devices are seeking higher performance and miniaturization.
As I explained earlier about semiconductors, their manufacturing process, and defects, electrical engineering is not just about devices that allow current to flow through them, but also includes a variety of studies to improve their reliability, optimize the manufacturing process, and reduce defects. Semiconductors are tiny devices, but they are at the heart of modern technology, including smartphones, computers, appliances, and cars, and their importance continues to grow. In recent years, semiconductor technology has been recognized as the foundation for the development of next-generation technologies such as self-driving cars, artificial intelligence, and the Internet of Things (IoT). Advances in semiconductor research will make many of the technologies of the future possible.
We hope that this brief explanation helps readers understand that the electronic devices they encounter every day are not just a combination of components, but the product of precise processes and research for reliability and efficiency.
