Silicon Carbide Power Devices

Silicon carbide (SiC) is a wide bandgap semiconductor found naturally as moissanite and mass produced since 1893 as powder and crystal forms.

Wolfspeed’s SiC products and expertise enable designers to craft lighter, smaller industrial power designs using less energy for better efficiency.

High efficiency

Silicon is widely considered to be the go-to semiconductor material in electronic devices, yet is beginning to reach its limits when dealing with higher power applications that demand higher temperatures, voltages and speeds. For these high-powered applications, wide bandgap materials like silicon carbide (SiC) or gallium nitride (GaN) offer better performance in power electronics devices.

SiC power devices offer greater energy efficiency compared to their silicon counterparts, thanks to operating at higher temperatures and with less heat lost due to heat transfer within the device. This cuts operational costs while prolonging its lifespan while reducing cooling system expenses.

Attaining this high efficiency is achieved using a SiC power MOSFET circuit operating in a p-channel mode, which enables current to flow only in one direction while blocking it from flowing in both. This greatly enhances power converter efficiency, leading to reduced Joule heating during operation.

Silicon carbide stands out from traditional semiconductors by withstanding higher electric fields, making it suitable for high-voltage applications like power supplies for renewable energy sources and making it essential for green power installations that prioritize yield and minimize maintenance costs.

Silicon carbide power devices are increasingly prevalent, from industrial motors to transportation systems. Their lightweight properties and power saving properties have made them essential components in new energy vehicles such as hybrid cars.

Silicon carbide’s unique physical and electrical properties make it an excellent material for power distribution circuits, with low voltage loss, high temperature resistance, low on-state resistance and fast switching capability making for more efficient and reliable power conversion.

Silicon carbide’s reliability and lifetime can be improved using proper processing techniques. One such technique is wafer thinning, which reduces wafer thickness to increase active area and efficiency as well as conductivity of SiC chips while simultaneously improving stability through eliminating surface defects.

Miniaturization

Silicon carbide power devices have recently seen significant momentum in the industry due to their excellent energy efficiency and small size. These devices can be utilized in power converters and inverters as well as being an economical alternative to silicon semiconductors; furthermore, these devices feature higher voltage levels and switching frequency rates making them suitable for high-speed applications.

Furthermore, they provide greater reliability and thermal stability. SiC material’s high temperature tolerance makes it ideal for power electronics applications; additionally, its low resistance enables high switching frequencies at reduced voltages with no wasted electricity consumption resulting in decreased operating temperatures and extended device lifespan.

Demand for wide-bandgap SiC power devices has seen dramatic growth, particularly for electric vehicles. To meet market requirements and stay competitive, vertically integrated suppliers need reliable production processes that produce large wafers with high performance device structures and large diameter wafers with tight tolerances.

Silicon power semiconductors have traditionally been produced using the Lely process. This involves sublimation of SiC powder under high temperature conditions to form various species of silicon, carbon and disilicon carbide which then crystallized into flake-like single crystals with diameters reaching 2 cm before they were placed onto substrates in an argon gas environment at 2,500 degC for deposition on a substrate before moving on to a colder environment to grow device structures.

Power electronic devices play an essential role in developing renewable energy sources. They convert electrical energy to other forms, and their performance depends heavily on the power semiconductors they employ. Silicon is often chosen because it is inexpensive and easily understood; however, its performance has become limited, forcing manufacturers to seek wider bandgap materials such as silicon carbide, gallium nitride, or tungsten carbide instead for fabrication of power semiconductors; wide bandgap SiC-based semiconductors offer increased power efficiency with decreased thermal loss.

High-temperature resistance

Silicon carbide semiconductor is experiencing a revolution in power electronics, ushering in new levels of efficiency and performance. Due to its unique electrical properties, silicon carbide devices are quickly replacing existing silicon based devices in applications such as electric vehicles, high speed railways, photovoltaic power generation and smart grids.

SiC’s unique physical and electronic properties enable it to withstand much higher temperatures than traditional silicon semiconductors, with its natural atomic bonding structure consisting of tetrahedral carbon-silicon atoms offering superior hardness, strength, thermal conductivity and chemical resistance that makes it suitable for high performance power devices operating in harsh environments.

SiC is known for its superior thermal resistance and electrical insulation properties compared to traditional silicon semiconductors, making it well suited to use in high-speed devices such as Schottky barrier diodes (SBDs), insulated gate bipolar transistors (IGBTs), and MOSFETs.

One of the greatest challenges of fabricating power semiconductors lies in lowering their voltage-blocking channel resistance, which limits their performance and the switching frequency. SiC power devices offer significant resistance savings at equivalent breakdown voltage due to their thinner n-layer. Furthermore, these n-layers can be more heavily doped than their Si counterparts for additional reduction in channel resistance.

Conventional SiC semiconductors suffer from high turn-on resistance and significant switching losses, which restrict their application to lower frequencies. To address these problems, high-quality SiC devices must be manufactured using highly reliable techniques – this requires optimizing epitaxial growth processes while guaranteeing that their n-layer has an extremely low carbon vacancy density.

Silicon carbide power devices exhibit excellent temperature resistance due to their unique atomic bonding structure. This allows electrons to pass more freely through the n-layer and across junction interfaces, leading to lower on-state resistances and consequently resulting in greater efficiency and lower losses within devices as well as faster switching speeds and enhanced power transfer capacity.

Low loss

Silicon carbide power devices offer many advantages over traditional semiconductors, including lower loss. They produce less heat and can be switched on and off at faster speeds to help lower energy costs and operating temperatures, helping lower operating temperatures as a result. Furthermore, their ability to withstand higher voltages and currents makes them suitable for high-speed applications like motors and generators, making them an essential component in power supplies.

SiC provides more surface area for electrons to pass through, leading to lower conduction and switching losses as well as less energy lost through heat loss – all contributing to improved power efficiency. Furthermore, power supplies constructed using SiC power modules may be smaller and lighter than traditional silicon components, reducing cooling system requirements as well as space costs.

SiC-based power devices boast increased efficiency as well as higher operating temperatures and voltages than silicon-based semiconductors, making them suitable for applications requiring fast switching circuits such as data centers or electric vehicle drive converters.

SiC power devices stand out for their low loss due to superior thermal and electrical properties, with the latter helping these power devices withstand up to 650V of voltage and 100A current – far exceeding their silicon counterparts and making them suitable for industrial equipment, data storage solutions and renewable energy systems.

SiC power devices can reach high withstand voltages by employing Schottky barrier diodes and metal-oxide-semiconductor field-effect transistors (MOSFETs). Their insulating gates block current from flowing across them, so their drift layer resistance is lower compared to silicon devices and allow them to operate at higher switching frequencies without compromising reliability.

SiC has an n-layer that is 10 times thicker than silicon for any given breakdown voltage, enabling more efficient current flow and doping density, giving greater control of electrons and holes through more active doping of its n-layer, an integral element in IGBTs and bipolar transistors used in high voltage applications like electric vehicles or wind or solar power generation systems.