Introduction
Silicon carbide (SiC) semiconductors have become more prominent in the semiconductor industry. In the past, a semiconductor used silicon as its main base material. However, since the introduction of silicon-carbide (SiC), semiconductors seem to be more functionally efficient, durable, and effective.
This article provides a good explanation of what silicon carbide is and why it has recently become a major element in the semiconductor industry.
What is Silicon-Carbide (SiC)
Silicon carbide (SiC) is a ceramic material mostly used to produce heating elements in the manufacturing industry. The trade name of this semiconductor material is Carborundum. Some of the manufacturing elements that this ceramic material is used to produce include crucibles, burner nozzles, and slide bearings.
Other elements produced from SiC include wear parts, sealing rings, heat exchangers, and sintering aids. So, to answer the big question, “Why the recent adoption of SiC in semiconductors?” It’s because silicon-carbide semiconductors offer higher mobility of electrons and higher thermal conductivity, all while ensuring lower power losses.
SiC Doping
A comparison of SiC and other semiconductor materials with wide band gaps shows that SiC handles higher concentrations of wide dopants. It might interest you to know that there is a high probability of this through ion implantation or in-situ doping.
In most cases, SiC’s doping uses donor-type impurities such as phosphorus and nitrogen. Acceptor-type impurities such as gallium, boron, and aluminum are also commonly used to increase the conduction of electricity. Nitrogen substitutes for Carbon while silicon is substituted with boron, aluminum, and phosphorus in the SiC lattice.
When doped with nitrogen, SiC produces an n-type semiconductor. Meanwhile, a p-type semiconductor is the result of doping with boron, aluminum, and phosphorous. The lattice parameter of this semiconductor material tends to change based on doping density and the dopant.
Another factor that causes changes in its lattice parameter is the temperature that allows for the formation of crystals. When SiC is doped with nitrogen, a contraction of the lattice is observed. In contrast, an expansion of the lattice is usually the case when doping is done with aluminum.
Lattice stress caused by a mismatch in the lattice due to doping is a crucial factor. It’s especially significant during device fabrication, particularly during the stage of heterostructure formation.
Properties of Silicon-Carbide (SiC)
Silicon carbide is both the hardest and the lightest ceramic material you can find. It’s a compound derived from combining silicon with carbon, and it’s resistant to acids and lyes. Furthermore, SiC is composed of several chemical, mechanical, and thermal properties that make it a fitting semiconductor material.
These properties include intrinsic body diode (MOSFET device), high energy efficiency, low switching and power losses, and low thermal expansion. Others include outstanding thermal shock resistance and a high operating temperature and frequency that allows it to operate at around 200℃.
Additionally, it has excellent thermal management properties, allowing for a reduction in cooling requirements. All these properties make it possible for SiC diodes and transistors to function without losing their effectiveness and reliability.
Comparison Between Silicon and Silicon Carbide in Semiconductors
One advantage that silicon carbide semiconductors have over silicon semiconductors is in the strength of electric field breakdown. The strength of the electric field breakdown in SiC semiconductors is 10x that of a silicon semiconductor. Hence, a semiconductor that uses silicon carbide can configure the extremely high voltages of high-power devices.
SiC semiconductors have thinner drift layers and high impurity concentrations. These properties facilitate its ability to handle between 600V and over a thousand volts. In addition, a SiC semiconductor is composed of an immensely low ON-resistance per unit area. This low ON resistance also supports its ability to withstand high voltages.
Furthermore, the drift layer resistance per area of silicon carbide semiconductors can be decreased by 300x. That is, in comparison to silicon semiconductors when they are exposed to the same voltage level. Typically, silicon semiconductors have to be supported with minority carriers like IGBTs to minimize the increase in ON resistance.
However, when these Insulate Gate Bipolar Transistors (IGBTs) are used as carrier devices for silicon semiconductors, switching losses increase. Consequently, more heat is generated, and high-frequency operations become limited.
On the other hand, SiC semiconductors use majority carrier devices (MOSFET and Schottky barrier diode) to withstand high voltages. It employs lower ON resistance to simultaneously facilitate high-speed device construction and high-speed operations while withstanding high voltages.
Silicon carbide semiconductors also have a wider bandgap (3x that of a silicon semiconductor). Thus allowing for power devices to run at higher temperatures and expanding applicability to a considerable level.
Uses of SiC Semiconductors
You can use silicon-carbide semiconductors to power modules that are used in high-efficiency and high-power applications. Silicon-carbide semiconductors such as FET/MOSFET transistors and Schottky diodes are components of most devices for power supply. They include battery chargers, converters, motor control systems, and inverters.
Silicon-based semiconductors have a voltage limit of 900V. However, this is not the case for an SiC semiconductor. Are you interested in seeing how they differ?
Silicon carbide semiconductors can handle voltages that go as high as 10kV. In addition, the low switching losses support high operating frequencies, allowing it to achieve even higher efficiencies.
The application of SiC semiconductors in inverters and converters can lower system losses by approximately 50 percent. They also lower the size by 300 percent and the overall cost of the system by 20 percent. This ability to lower overall system size highlights the usefulness of SiC semiconductors in space-sensitive applications.
Current Silicon Carbide Market Trends
The manufacturing of SiC devices is undergoing notable advancements. You will notice this in the quality of SiC substrates and the process of epitaxy to facilitate uses for silicon carbide. Active effort is being made by researchers to correct certain SiC substrate defects, including micro-pipes and stains.
Other substrate defects that are being corrected include crystalline stacking faults, surface particles, and scratches that lower SiC device performance. A higher density of these defects is being resisted by efforts to maintain consistent substrate quality, even with larger SiC wafers.
However, implementing these advancements will enhance the quality, reliability, and cost-effectiveness of SiC semiconductors, among other SiC devices. Thus creating several growth opportunities for the SiC market. Further advancements in SiC devices and technology comprise a shift towards creating larger wafers.
Moreover, developing larger wafers suggests the increased adoption and application of SiC devices in high power electronics and applications. It also holds potential for the heightened increase in the demand for SiC MOSFETs in EV/HEV powertrains.
Applications of Silicon Carbide
If you are wondering about the areas where you can apply this ceramic material, then look no further. The hardness of the material makes it suitable for an extensive range of applications. Besides semiconductors, SiC applies to electric vehicles, electronics and phototonics, aerospace, and the military.
Are you aware that silicon carbide components apply to traditional fields as well? This includes abrasives, cutting tools, and refractory materials, among others. You will also find that SiC plays a significant role as a component of automotive parts - brakes and clutches.
Are you a manufacturer of bullet-proof vests or body armor? Find quality SiC materials for your products to contribute to the military here on our website. The resistance of silicon carbide to cosmic radiation makes it a perfect material for the aerospace industry.
It will also interest you to know that SiC is applied to the manufacturing of rocket nozzles. During rocket propulsions, the rocket nozzle is usually subjected to intense heat. If the material is incapable of containing the heat, the entire operation will fail.
They are also used to improve energy efficiency in renewable energy systems. You should also know that SiC-based devices are used in high-power RF applications.
There are also a lot of upcoming advancements in the technology industry, especially with the development of 5G technology. For 5G networks to function seamlessly, it requires high-power RF applications that function at high frequencies.
Therefore, you are bound to notice an increase in demand for silicon carbide following an expansion in 5G technology adoption.
Silicon Carbide Market Value
You can find the finest quality of silicon carbide, among other porous and textile ceramic materials, at GGSceramics. Several factors determine the price of each SiC, including grits, type, mesh, quantity, and market conditions. However, you get your money’s worth for the purchase of silicon carbide with us. Feel free to send an Inquiry today.
Frequently Asked Questions (FAQs)
Can SiC Outperform IGBT at High Frequencies?
Yes. SiC can outperform insulated gate Bipolar Transistors (IGBTs) at high frequencies. IGBTs were used in the past as minor carriers for silicon semiconductors to repress an increase in ON-resistance. However, the switch to SiC was made when researchers discovered that silicon carbide semiconductors had naturally low ON-resistance as a property.
Why Can SiC Handle High Voltages?
The reason silicon carbide semiconductors can handle high voltages is their electric field breakdown strength. Compared to the dielectric breakdown intensity of silicon semiconductors for electric fields, the strength of SiC devices is 10x higher. Thus, SiC semiconductors withstand higher voltages ranging from 600V to over one thousand volts.
How Does the SiC Reverse Recover Time Compare With Si?
The SiC MOSFET body diode has an extremely fast reverse recovery time (trr) with the values being negligibly small. The energy loss (Err) is also reduced to a considerable level compared to the Si MOSFET.
Conclusion
SiC semiconductors are rapidly becoming a game changer in the semiconductor industry, and the earlier you align with this trend, the faster you will see the benefits. Along with a plethora of other benefits, SiC can withstand more heat compared to silicon semiconductors, making it a more reliable material for use.