This blog post explains in simple terms what semiconductors are—the core of cutting-edge technologies like Samsung Electronics, smartphones, and self-driving cars—and why they are so important.
When people outside STEM fields first encounter the name “Department of Electrical Engineering,” the first thing that often comes to mind is usually topics like Samsung Electronics and semiconductors. While electrical engineering departments cover diverse fields beyond semiconductors—such as power systems, electronic circuit design, communication systems, and control engineering—the public often only encounters news like ‘Samsung Electronics’ semiconductor division posts record-high operating profit’ through mass media. This article focuses specifically on semiconductors, a subject of high public interest among the many areas covered in electrical engineering. We will explain what semiconductors are, how they are made, and the defects that can occur during their production, along with the resulting need for research.
Many people have heard the word ‘semiconductor,’ but few know its precise meaning. Generally, everyone knows about conductors and insulators. To summarize simply, a conductor is an object that allows current to flow well, while an insulator is an object that allows almost no current to flow. So what exactly is a semiconductor? It’s easy to misunderstand the term literally as a material that allows ‘half’ the current to flow. Semiconductors are usually made primarily using the element Si (silicon). Pure silicon is nearly an insulator, allowing almost no current to flow. However, by adding specific impurities to this silicon, the flow of current can be controlled. This is achieved by introducing impurities that create ‘electrons’ or ‘electron holes’ within the silicon atomic structure, giving the semiconductor properties intermediate between a conductor and an insulator.
Why go through the trouble of creating a semiconductor, where current doesn’t flow freely like in a conductor? The answer lies in the semiconductor’s unique advantage: the ability to control electrical conductivity. Electrical conductivity is a property indicating how well an object allows electricity to flow, comparable to the cross-sectional area of a water channel. Just as more water flows faster through a wider channel, higher electrical conductivity allows current to flow more efficiently. By controlling the type and amount of impurities, semiconductors can freely adjust this channel width, i.e., electrical conductivity. For example, there are p-type and n-type semiconductors. P-type semiconductors have the characteristic of allowing positively charged holes (holes) to move, while n-type semiconductors have the characteristic of allowing negatively charged electrons to move. By combining these two types of semiconductors, basic devices like diodes that control current flow can be created.
Using these semiconductors, the most fundamental electronic device, the transistor, can be made. Transistors possess the characteristic of being able to open and close the path through which current flows. This enables them to amplify or switch electrical signals. Current technology allows these transistors to be fabricated extremely small, down to tens of nanometers (nm). Billions of transistors are integrated into small devices like smartphones, enabling high-speed computation. Transistors are implemented at such a microscopic scale and can efficiently control the flow of electrical signals, making them the core components in various electronic devices and computers.
However, various defects can occur during the semiconductor manufacturing process. This leads to some of the billions of transistors not functioning as intended, significantly impacting the reliability of semiconductor devices. Specifically, defects called traps occur within semiconductors. These traps refer to states where electrons become ‘caught’ and unable to move during their flow. Traps function similarly to small holes in a water channel. If we attempt to flow water steadily drop by drop, a hole in the middle of the channel prevents the water from flowing properly, disrupting the device’s normal operation. This directly undermines the reliability of electronic devices and, in severe cases, can lead to failure.
To solve problems caused by traps, reliability research is essential. Electrical engineering conducts such research to identify the location and causes of traps, developing technologies to reduce them during the manufacturing process. Especially in today’s era where countless electronic devices pursue high performance and miniaturization, reducing defects in semiconductors is a critically important task.
As previously explained regarding semiconductors, their manufacturing processes, and defects, electrical engineering encompasses not only devices that conduct current but also diverse research into semiconductor reliability, manufacturing process optimization, and defect reduction. Though small, semiconductors are at the core of modern technology—smartphones, computers, home appliances, automobiles—and their importance continues to grow. Recent semiconductor technology is gaining attention as the essential foundation for developing next-generation technologies like autonomous vehicles, artificial intelligence, and the Internet of Things (IoT). Through the ever-advancing research in semiconductors, diverse future technologies will become possible.
Though this explanation was brief, I hope it helps readers understand that the electronic devices they encounter daily are not just simple combinations of parts, but the products of precise processes and research aimed at achieving reliability and efficiency.
