.jpg)
Semiconductors can be divided into groups based on their final use and production processes. From a silicon substrate to a germanium wafer, each material has a unique set of attributes and properties that make it especially appropriate for certain uses. Sorting them out makes it easier for manufacturers to understand each one.
Knowing a semiconductor's classification is crucial to comprehending its uses, manufacturing processes, and material characteristics. Here are some common types of wafers and the different criteria used to determine each one.
.jpg)
Semiconductors are materials that have electrical conductivity between that of conductors and insulators. Their unique electronic structure allows for controlled conductivity, making them an ideal component of today’s technology.
The most common semiconductor material is silicon, but many others are also used, depending on the application. Because there is such a wide variety of semiconductor materials today, and it’s only expected to grow, understanding the differences between each one with precision is key.
By mastering the classification of semiconductors, manufacturers can optimize the design of electronic components, choosing materials with intrinsic and extrinsic properties that adapt to their needs. Moreover, classifying semiconductors helps predict their behavior under various conditions, such as temperature and frequency.
This knowledge can help researchers, engineers, and industry professionals understand the advantages of each material and manufacturing process in ensuring reliable device performance.
One of the most significant classification methods for semiconductors is according to their material. Silicon is the most widely used material for wafers, mainly due to its worldwide availability. However, certain rarer, more expensive materials offer better electrical properties.
According to their composition, semiconductors can be broadly classified into:
All of these semiconductors are made of one element. The most notable example is silicon (Si), which is widely used in integrated circuits. Additionally, one of the earliest materials used in semiconductor devices was germanium (Ge).
Compound semiconductors are composed of two or more elements. These help reduce overall costs, improve the properties of materials, or even make them easier to handle. Depending on their constituent elements, compound semiconductors can be further classified into:
Organic semiconductors are carbon-based materials capable of conducting electricity. Because they are lightweight and mechanically flexible, they are being increasingly utilized in organic light-emitting diodes (OLEDs), flexible electronics, and organic photovoltaics.
Semiconductors can be classified depending on their doping levels. Doping is a process in which impurities are intentionally introduced into a pure semiconductor to modify its electrical properties. This helps create semiconductor devices that meet specific characteristics.
Depending on their doping levels, semiconductors can be broken down into:
Intrinsic semiconductors are pure semiconductor materials that contain no significant impurities. The material itself is the only factor influencing their electrical characteristics. For example, in intrinsic silicon, conductivity rises as the temperature rises because there are more charge carriers.
Extrinsic semiconductors are doped with impurities to improve their electrical characteristics. They can be divided into the following categories:
One important component that affects a semiconductor's electrical and optical characteristics is its energy band gap.
The energy band gap is the energy differential between a semiconductor's valence and conduction bands. That is the least amount of energy needed to transfer an electron from the valence band to the conduction band. Depending on the size of its band gap, they can be categorized into:
These materials, which usually have energy band gaps of less than 1 eV, are frequently employed in applications that call for thermoelectric and infrared detection materials. Lead sulfide (PbS) and indium antimonide (InSb) are two examples of narrow-band gap semiconductors.
Semiconductors with a wide band gap (greater than 2 eV) can function at higher voltages and temperatures. They are perfect for high-frequency and power electronics applications. Two examples of this are gallium nitride (GaN) and silicon carbide (SiC).
Last but not least, semiconductors can also be categorized based on their applications. As supply chains become more integrated, end applications often influence a semiconductor’s design and material choice.
Some common applications that affect this include:
To ensure effective operation, semiconductors used in digital circuits, such as microprocessors and memory devices, must be precisely doped and highly pure. In this category, silicon is the most widely used material.
Signal-amplifying analog semiconductors frequently call for specific materials and designs. Because of their high-frequency capabilities, materials like GaAs are used in operational amplifiers and voltage regulators, among other applications.
Power semiconductors are effective at controlling and converting electrical power. Because of their high breakdown voltage and thermal conductivity, materials like SiC and GaN are favored in renewable energy systems and electric cars.
Devices that emit, detect, or control light use optoelectronic semiconductors. Because of their direct bandgap characteristics, GaAs and InP wafers are designed with the aim of lasers and photodetectors, respectively, in mind.
The classification of semiconductors is a multifaceted process that considers more than one single factor at the same time. Material composition, intrinsic and extrinsic properties, energy band gap, and more factors are considered while describing what category a type of conductor belongs to.
Nevertheless, these complex labels are necessary to ensure the best type of substrate is used in every application. The classification method for wafers may evolve as technology evolves, and here at Wafer World, we’ll break it down in simpler terms. If you’d like to learn more about our wafers, reach out!
