Semiconductors: What They Are and How They Work

Semiconductors are distinctive materials that sit midway between conductors and insulators in terms of electrical conductivity. Semiconductors are the hidden heroes of the modern world, serving as the foundation across industries such as IT, MedTech, renewable energy, and automotive engineering. Their essential role in the creation of an array of electronic devices has subtly intertwined them with every part of our day-to-day life.

Semiconductors are literally everywhere. The device you’re reading this article on relies on them. Whether they’re in your phone, in your car, in the appliances that make your home comfortable and convenient, your morning alarm, the streetlights that guide you home at night, and so many more places- semiconductors make our modern life possible.

The unique ability of semiconductors to control electrical current explains their widespread use. This trait is important with key components like integrated circuits and transistors, the essentials of nearly all our digital equipment.

Semiconductors aren’t just personal assistants in our pockets or homes; they’re propelling the IT industry forward as they breathe life into the servers, desktops, and mobile gadgets that have become our workmates and sources of leisure. They’ve accelerated business processes, made global communication instant, and have even made remote work and digital commerce commonplace.

Healthcare also benefits from semiconductors by inhabiting complex imaging machines and inside lifesaving implants such as a pacemaker, a small device that’s placed under the skin in your chest to help control your heartbeat. They also quietly contribute to the planet’s wellbeing with solar panels, where they help convert the sun’s rays into usable electricity.

How Does a Semiconductor Work?

A semiconductor’s unique properties come from its atomic structure. It all begins at the atomic level, with atoms made up of a central nucleus surrounded by electron shells. For semiconductors, the outermost or valence shell is of particular interest. Semiconductors like silicon have four electrons in their valence shell, as opposed to conductors which generally have just one.

Atoms with the same valence combine to form crystal structures. It is often Silicon that is used to form said crystals, which is used as a foundation for integrated circuits (ICs), transistors, or diodes. Semiconductors are able to manipulate electric currents when electron flow and exposure to radiation are controlled.

The atomic configuration of semiconductors can be translated into many different practical uses. Silicon, for example, has a unique electron structure that facilitates the formation of crystal lattices which can be responsible for powering an array of high-tech devices. The most important part of this process is the stable crystalline framework it forms as it serves as a powerful platform to leverage the distinct electrical features native to semiconductors.

One of the fascinating aspects of semiconductors is their ability to adapt. Introducing certain other elements or ‘impurities’ into the silicon crystal lattice can change its electrical properties (the process known as doping), can create semiconductors that mainly carry either negative charges (electrons) or positive charges (holes).

What Does a Semiconductor Do?

N-type and P-type are the two categories semiconductors can be classified as. The primary current in N-type semiconductors flows through negatively charged electrons, much like how a wire conducts electricity. On the other hand, P-type semiconductors primarily transport current via ‘holes’ which are spaces where electrons could potentially exist.

The introduction of dopants can significantly affect the properties of semiconductors. Impurities have the ability to alter how semiconductors are dissipated by controlling their electrical properties. Substances such as silicon and boron are examples of common dopants and silicon is the most popular one as it forms the foundation of most ICs.

How the N-type and P-type semiconductors function is dependent on the dopants introduced to their structure. The dopants essentially donate either extra electrons or extra ‘holes’ (the absence of electrons) to the material. N-type semiconductors are created by introducing a dopant that has more valence electrons than the semiconductor material. For instance, phosphorus with five valence electrons can be used as a dopant in a silicon crystal that has four valence electrons. The extra electron is loosely bound and can move freely, creating a current.
On the other hand, P-type semiconductors are formed by using a dopant with fewer valence electrons than the semiconductor. An example is boron, with three valence electrons, used as a dopant in silicon. This leaves a ‘hole’, or a space where an electron could potentially exist, and the holes move through the lattice thus creating an electric current.
Both types of semiconductors together are the basis of most devices such as diodes, which are devices that’s currents can only flow in a singular direction, and transistors, which are formed by layering both N-type and P-type semiconductors. Electronic devices‘ functionality and abilities to perform complex operations are dependent on the semiconductors’ abilities to control the electricity flow based on the signal inputs.

From Silicon to Integrated Circuits: The Process

Integrated Circuits (ICs), the pathway semiconductor chips take, are very complex and include a complex process. The process begins with the circuit’s design, which is usually created by specialists. The completion of the design process means that the manufacturing process can commence, usually by foundries. Companies that carry out both the design and manufacturing steps are referred to as Integrated Device Manufacturers, or IDMs.


The development of an electronic circuit that fulfills specific functions like data processing or signal amplification digitally using software tools that allow designers to lay out multiple transistors on one chip. These circuit designs are tested and simulated extensively to ensure that they will work as expected once manufactured.


Following design completion, the manufacturing process kicks off with the creation of a photomask – a type of stencil based on the circuit design. This photomask is used to etch the circuit design onto a silicon wafer. The wafer then goes through a series of chemical and heat treatments to add various layers and dopants, transforming it into a complex 3D structure with electronic properties. It is important to maintain quality control throughout the manufacturing step to prevent errors as even the smallest error can result in a non-operational chip. Upon completion of the wafer, it is cut into single chips that are then packaged in preparation for the integration process of electronic devices.


The packaged chips are mounted onto circuit boards, often alongside other components such as resistors, capacitors, and connectors where specialist technicians work hand in hand with automated machines to place said components onto the board to complete the circuit, making it ready for the final stage before packaging and distribution.


This step is a very delicate and critical part of the process as it involves testing the functionality of the final product. This is to ensure the devices are of performance and safety standards set by regulation, legislation and even the manufacturers requirements. The testing involves monitoring the devices’ performance under different conditions to test their reliability and endurance. These conditions could be exposure to extreme temperatures, water or humidity levels, and electrical pressure. When the devices pass the tests, they can be sent in for packaging.

Packaging and Distribution:

The final step involves packaging the devices in preparation for the distribution step, where devices are sent to different sellers such as electronic stores and large suppliers for global distribution.

Semiconductors may be small in size, but they play a huge role in our digital development with every piece of technology we encounter and make use of everyday. Understanding where and how the technologies we use are made ensures informed consumer behaviours, savvy use of technologies, and overall appreciation for the skilled underdogs who work hard to make our lives more efficient and convenient.