SiC is experiencing an explosion, reviewing the latest progress of SiC abroad in January 2021

At the beginning of the new year, in the semiconductor field, silicon carbide (SiC) technology has appeared in many headlines from industry to academia. The rise of wide-bandgap semiconductors has been well documented in the past few years. New semiconductor materials such as gallium nitride (GaN) and silicon carbide (SiC) provide higher speed, efficiency and working conditions, and have proven to be very useful in high-voltage applications. These applications include power electronics, electric vehicles, etc.

SiC vs. GaN vs. SI

 In the month so far in 2021, SiC technology has appeared in many headlines across industry and academia. For example, this month ROHM Semiconductor announced the completion of a new factory built specifically to increase the company's SiC production capacity. The new factory will use the most advanced SiC manufacturing technology to improve production efficiency, expand wafer diameter and increase output. The new factory aims to reduce carbon dioxide emissions by 20% compared to traditional factories.

ROHM's Chikugo Plant This month alone, several research institutions and semiconductor suppliers have announced new SiC-based advances that may overcome the manufacturing and design challenges of this WBG. How Far Can SiC Go In academia, one notable SiC headline in 2021 came from the latest research from the Nagoya Institute of Technology. The research team proposed a method to non-destructively measure the carrier lifetime in silicon carbide devices. This is an important achievement because many researchers have been trying to balance SiC carrier lifetime - finding the best balance between sufficient conductivity modulation (which requires a long carrier lifetime) and switching losses (which require a short carrier lifetime). In the past, this effort could only be measured through invasive techniques, requiring researchers to actually cut open and analyze the semiconductor.

Non-invasive carrier lifetime measurement technique proposed by Nagoya Institute of Technology In their proposed method, the researchers use an excitation laser to create carriers and a probe laser with a detector to measure the lifetime of the excited carriers. With this technique that allows for simpler, non-invasive analysis, engineers can finally begin to fine-tune the carrier lifetime to achieve the perfect balance of conduction modulation and low switching losses. This could lead to a new generation of newer, higher-performance SiC devices in the future. Another SiC advance comes from researchers at the Fraunhofer Institute for Solar Energy Systems (ISE), who recently discovered a new type of SiC transistor that can be directly connected to the medium-voltage grid due to its high blocking voltage. These new devices are contrary to most inverters, which feed power to the low-voltage grid, but can be coupled to the medium-voltage grid using a 50-Hz transformer.

 The Fraunhofer ISE team created a 250-kVA inverter stack that includes 3.3-kV SiC transistors.

Vishay and Cree hope to simplify design with SiC Note: Cree will be renamed Wolfspeed at the end of this year While academic researchers are making progress in adopting SiC in R&D, industry suppliers are also putting more useful SiC-based devices into the hands of practicing engineers. For example, Vishay recently released new high-efficiency SiC Schottky diodes. The company released 10 new SiC diodes, all of which can withstand a VRRM of 650 V and forward currents of 4 A to 40 A. These new diodes are rated to withstand a maximum junction temperature of 175°C, allowing operation in very high temperature environments-this is critical for designers working in certain areas of power electronics. 

Specifications of the new SiC Schottky diode series. Image courtesy of Vishay The second piece of industry news comes from Cree, which announced the launch of its Wolfspeed WolfPACK power module. This new power module features Wolfspeed SiC MOSFETs and is specifically designed for use in the mid-power range. According to the company, the goal of the product is to maximize power density while minimizing design complexity. Intended for applications such as EV fast charging and solar, the series offers an operating voltage of 1200 V, forward currents of up to 105 A, and R DS(on) of 11 milliohms at 25°C. This could be a boon to designers who have struggled to integrate a suitable SiC solution due to the pitfalls of design complexity. Strong start for SiC From academic breakthroughs to new products coming to market, SiC technology looks set to grow rapidly in the coming years. In fact, some industry analysts predict that the global SiC market will surge from $749 million in 2020 to $1.812 billion by 2025.