Did you know that home appliances to every electronic device you use in your daily life carry semiconductors? They are used to make the electrical conductivity smoother in those appliances. Over the years, semiconductor technology has become a part of almost everything in our daily lives. From mobile devices in your hand to transportation and other electronic devices, the semiconductor industry is everywhere to improve other technologies and do wonders for day-to-day life.
But what exactly is a semiconductor? Let’s go into more detail about what they are and what makes them so versatile in this article. Also, we are going to talk about how semiconductors work, the different types of semiconductors available in the market, and their advantages. If you are interested in getting to know about them, stay tuned with us for more details.
What Is A Semiconductor?
Semiconductors are made of elements with specific electrical properties. If you want to know further, a semiconductor is a material that has specific electrical properties which permit it to function as a substructure of electronic devices such as computers, phones, etc. It is ordinarily a solidified chemical element or compound that conducts electricity under certain conditions. In some cases, it acts as a resistor. This specific quality of semiconductors has established itself as the best way to manage electrical current flow through everyday electrical appliances. Silicon is one of the most popular materials used in semiconductors. Gallium Arsenide is another most commonly used semiconductor as the current flows uninterrupted through it.
A Brief History Of Semiconductors
Walking back to the history of semiconductors, first, we must mention the invention of the rectifier in 1874. Decades later, scientists in the US invented the point-contact transistor in 1947 and then the junction transistor in 1948. These are the landmarks in the birth of semiconductors. After the invention of the transistor, semiconductor chips came to life and the industry grew immensely.
That’s when the bipolar integrated circuits came into the spotlight and it had a major impact on the development of semiconductors. The IC or integrated circuit technology gave a boost to the semiconductor industry as with the progress of IC, its broad functioning and high performance expanded widely towards its fields of application. Since the dawn of the 2000s, with the help of the integrated circuit field, semiconductors are now used in every nook and corner of society from mobile phones, computing components, and other electronic components to healthcare appliances and more.
How Does A Semiconductor Work?
To understand how semiconductors work, you need to first understand the electrical conductivity of materials. There are materials that conduct electricity, called conductors and there are materials that do not, called insulators. Conductors such as gold, silver, and copper are known as things that have to contain low resistance and conduct electrical current easily. On the other hand, insulators like rubber, glass, and ceramics are known for their high resistance and zero electrical conductivity.
Semiconductor materials fall in between these two. Under certain temperature conditions, they act as insulators but at certain temperatures, they start conducting electricity, thus giving them the name semiconductors. This is due to the atomic structure or the material.
A material’s electrical conductivity depends on how electrons are arranged in its atomic structure. Electrons are organized into layers called shells within an atom, and the outermost shell is called the valence shell. The electrons in this valence shell are the ones that form bonds with other atoms. The mobility of these electrons decides the level of electrical conductivity of a material.
The valence electrons in metals need lower energy to escape and that is why they are good conductors. On the other hand, valence electrons in insulators are highly stable and need extremely high levels of energy to become free. The valence electrons in semiconductors are stable up to a certain temperature and act as insulators until they reach it. Once they reach that temperature, the valence electrons will absorb the energy and become mobilized turning them into electrical conductors.
In the semiconductor production process, there is a process called doping. This process can affect the electrical conductivity of a semiconductor. Semiconductor companies use doping to create the desired level of conductivity in semiconductors making this quite an important part of the process.
The level of electrical conductivity in a semiconductor can be influenced by adding other elements, commonly called impurities or dopants. Pure semiconductors have a certain level of electrical conductivity. When some elements are added to the semiconductor, the game changes. Depending on the impurity used, the conductivity can increase or decrease.
If a dopant with more electrons is added, like Phosphorous, the electron mobility is increased thus increasing the electrical conductivity. But if an impurity like Boron which has more holes than electrons is added, the mobility of the already free electrons is lowered. This is because the valence shell in a Boron atom has a gap or a hole where a free electron can form a bond. This would lower the conductivity of the semiconductor.
Types Of Semiconductors
There are two main types of Semiconductors. Let’s see what they are,
The intrinsic semiconductors or elemental semiconductors are something that is made to be chemically pure. The specialty of it is, intrinsic semiconductors’ builds are not complex, as it is made up of only a single type of element. Two common semiconductor compounds are Silicon and Germanium. They both have four electrons, which means they’re good at forming covalent bonds.
When Germanium or Silicon is cooled down to absolute zero, all of the valence electrons are bound to the neighboring atoms. But when they are heated, some of the electrons become free and can move around. These are called free electrons.
When an electron moves from its original position, it creates a “hole” where it used to be. These holes and mobile electrons contribute to the conduction of electricity in the intrinsic semiconductor. The number of free electrons and holes is equal, which means the semiconductor carries both negative and positive charges.
Extrinsic semiconductors are the ones that are doped with specific impurities. The electrical properties of the semiconductor get modified by the impurities and make it more suitable for electronic items such as diodes and transistors. During the process of adding impurities, when a small amount of suitable impurity is added to pure material, it changes the conductivity of the material. Most semiconductors in use today are extrinsic semiconductors because their properties can be adjusted to suit specific requirements. The types of dopants that are being used build two types of semiconductors such as n-type semiconductors and p-type semiconductors.
An n-type semiconductor is made by doping pure elements with a pentavalent impurity element. This just means the impurity has five outer electrons. This fifth electron is the key factor when it comes to such bonds in the valence layer. The most common impurities used are phosphorus, arsenic, antimony, bismuth, or other similar elements. These impurities are called donor impurities.
When you add these impurities to a semiconductor material like Silicon, they increase the number of electrons available for conduction around the silicon atom, which makes the material a lot more conductive than before. The amount of impurity added is very small compared to the amount of semiconductor used.
So, by carefully controlling the amount of impurity added, it is possible to change the way the new semiconductor works. Even the addition of just one electron can change the ability to conduct electric current. This type of semiconductor is called n-type because it has more electrons available for conduction and they are negatively (or “n”) charged.
When you add a trivalent impurity (like Boron or Aluminum) to pure semiconductors like Germanium or Silicon crystals, the result is a p-type semiconductor. This impurity has three valence electrons, which means it has a space or a hole available for an electron to occupy.
In a p-type semiconductor, the number of holes is much higher than the number of thermally generated electrons. This means that it has a lot of positive charge carriers. Even though only a small amount of impurity is added to the pure semiconductor, it creates millions of holes in the semiconductor material. The name “p-type” comes from the fact that the material has a lot of positive charge carriers.
The Advantages Of Semiconductors
There are several advantages of semiconductors and let’s take a look at them,
- Semiconductor devices don’t have filaments.
- A vacuum is not necessary for a semiconductor device to operate.
- Semiconductors are shock-resistant. They also consume less electricity, are smaller in size, and occupy less space.
- Semiconductor devices need a low working voltage.
- Once a circuit device is turned on, semiconductor devices can be operated right away.
- Semiconductors do not hum when running.
- Circuits that employ semiconductors are also compact due to their small size.
- Semiconductors are far more sensitive to radiation and temperature.
- Semiconductors are less expensive and have a considerably longer shelf life.
Uses Of Semiconductors
There are many industries and manufacturers that employ semiconductors in their products including microchips, microprocessors, memory, and graphic processing units in computers, and in the field of telecommunication. They are also used in household appliances such as fridges, microwaves, washing machines, air conditioners, and other machines.
Not limited to these fields, but also semiconductors are employed in the banking, security, and healthcare fields as well. The field of manufacturing and transportation also benefits from semiconductors. So no field or industry is free from the use of semiconductors. This is the biggest innovation of the century in the field of electronic equipment.
Get Your Semiconductor Components From A Trusted Supplier
We talked about what semiconductors are, how they function, and their advantages.
If you want to know more about semiconductors, their components, usage, and more you can read our Inquivix Technologies Insights to gain more knowledge.
Inquivix Technologies is one of the leading suppliers of semiconductor components to manufacturers in industries such as automotive, aerospace, transportation, telecommunication, healthcare, and more. Based in South Korea, the center of semiconductor manufacturing, we are well-equipped to meet your requirements. If you are interested in sourcing the highest quality semiconductor components from South Korea, contact us today.
A semiconductor is a material that shows characteristics between a conductor and an insulator. This unique property is used by electronic device manufacturers to create compact, high-functioning products such as electronic chips
Semiconductors are in high demand across the world as all electronic devices contain semiconductors. It is an essential product in today’s technology-driven world.