Introduction
Technological advancements in the power electronics industry are on the rise thanks to Silicon Carbide Wafers. These specialized semiconductor materials offer unique attributes that make them the best options for the production of devices that demand high frequency and high power. This article will explore Silicon Carbide wafers, their characteristics, and their applications.
Characteristics of Silicon Carbide Wafers
A Silicon Carbide (SiC) wafer is a thin piece of crystalline material produced from the compound semiconductor, Silicon Carbide. These two elements in the semiconductor wafer have their atoms bonded together covalently, creating a rigid crystal lattice structure known to be highly stable. At its core, it has remarkable hardness and the ability to conduct heat while maintaining good performance levels in devices.
SiC wafers possess a wide bandgap (approximately 3.3 eV) that allows whatever devices they are placed in to produce its best result under high temperatures and voltages.
Silicon Carbide Wafers can be in several forms, with the main ones being the 4H-SiC and 6H-SiC formats used across various sectors, especially the power electronics industry. The structure of the wafer’s crystal lattice is represented by the letter H, while the stacking sequence of the atoms within the crystal structure is represented by the numbers 4 and 6.
These semiconductor wafers or substrates, as they are sometimes called, are excellent at transferring heat from one point to another, resisting oxidation, increasing efficiency, and also making them superior to Silicon wafers. They boast great electrical conductivity; hence, they are used in applications ranging from electric vehicles (EVs) to computer chips, aerospace, lasers, LEDs, optical receivers, Schottky diodes, MOSFET transistors, solar cells, and integrated circuits.
With a standard diameter between 150mm and 200mm and sleek flatness, SiC wafer devices tend to have better and faster switching speeds, smaller sizes, and impressive immunity to overheating because of their ability to manage high temperatures and voltages.
Doping SiC Wafers
To control the electrical properties of silicon carbide wafers, a process called doping has been adopted over time. It is the introduction of impurities into SiC wafers through various techniques such as ion implantation and immobile doping during epitaxial growth. These various techniques, over time, have all been properly improved, leading to controlled doping activation and concentrations. Some of these dopants include the electron-rich Nitrogen (n-type) and boron, which controls p-type conductivity.
Types of SiC Wafers
There are two major SiC wafer types:
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Polished SiC wafer
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Epitaxial Crystalline SiC wafer
The polished SiC wafer is a single Silicon Carbide disc comprising highly purified SiC crystals used mostly in high-power electronics. They are available in diameter sizes ranging from 100 mm to 150 mm.
On the other hand, the epitaxial crystalline SiC wafer type, also called n-type epitaxy, is formed from the addition of several crystals of silicon carbide to a surface. Here, the thickness of the material is carefully controlled.
Properties of Silicon Carbide Wafers
Some of the unique qualities that make SiC Wafers outstanding are:
1. Efficient utilization of energy.
2. Longevity and ability to work at high frequencies.
3. Ability to operate in temperatures up to 200°C.
4. Low switching losses.
5. High thermal conductivity
6. Lower thermal expansion.
7. Strong electron and hole mobility.
8. High breakdown electric field.
9. Impressive thermal resistance.
10. Excellent resistance to oxidation and harsh conditions.
Comparison between Prime and Research Grade Silicon Carbide Wafers
When it comes to Silicon Carbide wafers, there are usually two different grades you can choose from: The Prime Grade and Research Grade Sic Wafers. However, both grades have their pros and cons. Factors like acquisition cost, its application, and defect in densities, can be vital to consider when you want to make your choice.
Prime Grade Silicon Carbide Wafers
You can use this type of wafers for high-end applications that require a very high level of performance and dependability. This high grade of Silicon Carbide wafers has high purity levels and a very low level of defect densities making it a good choice for you to consider. This quality is what enables them to perform very well under any condition, giving you little or no errors.
Prime Grade SiC Wafers are very useful in the aerospace, high-end computing, computer chip technology, energy power converters, and power electronics sectors. The reason for this is because these sectors have no room for failure, which then makes this wafer more expensive when you compare it to other research-grade variants.
Characteristics - Prime Grade SiC Wafers:
1. Prime grade SiC wafers usually have a usable area of approximately 90%.
2. They also have a very low defect density.
3. These wafers possess a micropipe density of 5/cm².
4. They exhibit uniform resistivity of about 90%.
5. Prime Grade SiC wafers have the best values in terms of overall thickness, warps, and bow, making them efficient and stable semiconductors.
Research Grade Silicon Carbide Wafers
This type of wafer gives you a balance between quality and cost. If you are looking to develop, create new ideas and innovations, or perhaps you want to experiment on semiconductor projects, then research-grade SiC wafers are your option. These wafers don’t provide as much precision as prime-grade SiC wafers because they have a higher defect density and more variability.
Although this wafers can still offer you a reasonable amount of high-standard operations, they are specifically made to be cost-effective and suitable for experimentation and less critical projects like academic and research work.
Characteristics - Research Grade Silicon Carbide Wafers:
1. These wafers have a usable area of around 80%.
2. They also have a higher defect density, and a micropipe density of 10/cm²
3. Their uniform resistivity is about 80%.
5. They have better but not optimal thickness, bow values, and warp.
You have clearly seen that when it comes to choosing either Prime or Research Grade SiC wafers, the best option for you is based on what you intend to use it for. For example, if you are a college student who is doing research for a new semiconductor, then research-grade SiC wafers could be the best option for you, but it would be different if you are a manufacturer looking to produce high-end applications where there is minimal room for errors.
The Various Ways SiC Wafers Can Be Applied
There are several areas where you can apply SiC wafers, these areas include in power devices such as Schottky diodes, MOSFET transistors. You can also apply them in optoelectronics, computer chips, wireless infrastructures, and aerospace and military operations, like satellite communication systems and radar systems, renewable energy systems comprising solar system inverters, wind turbine converters, hydroelectric projects, etc
Sic Wafers’ Current International Trend and Market Value
If you carefully look at the current market value and global trends of SiC wafers, you would see that SiC wafer applications are gaining significant waves. Ever since 5G was invented and it began to massively be adopted worldwide, the demand for SiC wafers has since skyrocketed.
In 2021, the market value of SiC wafers rose to approximately $367.8 million, and it now has a Current Annual Growth Rate (CAGR) of 19.1%. Despite a 12.1% decline in 2020 due to the COVID-19 global pandemic, market analysts project it will exceed $1.4 billion by the year 2029. Interestingly, North America has become a leading contributor to the silicon carbide wafer market, while Shin-Etsu Chemical remains the world’s biggest SiC wafer supplier.
However, here at GGSCeramics, we provide a great blend of top-quality and affordable SiC wafers to satisfy your semiconductor needs.
Frequently Asked Questions
Why are semiconductors used in chips?
Semiconductors are used in chips due to their ability to properly control the flow of electric currents in the system without necessarily disrupting the general system functions.
What differentiates silicon wafers from silicon carbide wafers?
Silicon carbide wafers have a bandgap that is ten times that of silicon wafers. This means they can accommodate higher temperatures, voltages, and also a better thermal conductivity than silicon wafers.
Why are Semiconductor Wafers Commonly Used in Electronics?
Semiconductor wafers are commonly used in electronics because they have the inherent ability to conduct the flow of electricity and also control it effectively, thereby making it easy for them to serve as the control system for the flow of electric current between components in an electric device. This special attribute also shows why they are still being used in the production of computer chips and integrated circuits.
Conclusion
While still churning out high performance at a low cost, Silicon Carbide Wafers have undisputedly become a major catalyst in the growth of the semiconductor industry worldwide. From its numerous applications in power electronics to aerospace and several other mind-blowing innovations, it’s surely breaking records and setting new ones soon.