Integrated circuit

An integrated circuit (IC) is a compact assembly of electronic circuits. It is often called a microchip or simply a chip. These assemblies consist of many electronic components, such as transistors, resistors, and capacitors. These parts are interconnected on a thin, flat piece of semiconductor material. Most commonly, this material is silicon. Integrated circuits are essential to modern life. They perform vital functions like data processing, control, and storage. They are found in computers, smartphones, and televisions. These chips have transformed electronics by making devices smaller and faster. They also make technology much less expensive to produce.

To understand how an IC works, we must look at how it is made. Instead of building components one by one, engineers use a process called photolithography. This method allows the entire circuit to be printed as a single unit. This is much faster than using discrete components. Because the parts are so small and close together, they can switch very quickly. This proximity also means the chip consumes very little power. However, making these chips is not easy. There is a very high initial cost to design them. It also requires enormous capital to build the necessary factories. Because of this, ICs are most successful when they are produced in very high volumes.

There are different ways to build these circuits. In a strict sense, a monolithic integrated circuit is built on a single piece of silicon. However, the term is often used for other technologies too. Some use 3D IC or 2.5D IC structures. Others use hybrid integrated circuits or thin-film transistors. Modern chips are often based on the metal-oxide-semiconductor field-effect transistor, or MOSFET. These form what are known as MOS integrated circuits. MOSFETs are very useful because they can be easily isolated from one another. This allows engineers to pack many more transistors onto a single chip.

The history of the integrated circuit began in the late 1950s. In 1957, Jack Kilby proposed a new idea to the U.S. Army. He wanted to move beyond small ceramic modules called micromodules. In September 1958, Kilby demonstrated the first working integrated circuit. His version was made of germanium and used external gold-wire connections. While groundbreaking, this design was hard to mass-produce. In 1959, Robert Noyce at Fairchild Semiconductor developed the first practical monolithic IC. Noyce used silicon and the planar process. This process allowed for reliable aluminum interconnections directly on the chip. Most modern chips follow Noyce's design.

Since those early days, the capacity of chips has grown enormously. This growth often follows Moore's law. This principle suggests that the number of transistors on a chip doubles roughly every two years. In the early 1970s, computer chips were much slower and smaller in capacity. Today, a modern chip can have many billions of transistors. You might find billions of them in an area the size of a human fingernail. As of 2016, some chips can have up to 25 million transistors in just one square millimeter. This incredible progress makes our current computers millions of times more capable than those from fifty years ago.

Integrated circuits have expanded far beyond simple electronics. Some chips are designed to be sensitive to light. These are called charge-coupled devices. They have largely replaced photographic film in many scientific and consumer tools. Other chips use microelectromechanical systems, or MEMS. These are very small mechanical devices driven by electricity. You can find MEMS in inkjet printers and even in car airbags. There is also a field called photonics. This involves using light within integrated optical circuits. These advances show how the tiny world of the chip connects to many different sciences.