Formed by the combination of two or more elements in the periodic table, especially from the groups III, IV, V, and VI, compound semiconductors have played a vital role in the evolution of electronics. In particular, silicon carbide (SiC) and gallium nitride (GaN) have gained immense popularity in the semiconductor space in the past decade due to their ability to work at high voltages, high frequencies, and high temperatures in comparison to silicon. Typical SiC and GaN devices include transistors such as field effect transistors (FETs), MOSFETs (metal oxide semiconductor FETs) and high electron mobility transistors (HEMTs), Schottky diodes and monolithic microwave integrated circuits (MMICs). While GaN is used for medium voltage applications (<650 volts [V]), SiC is used in high voltage applications (< 1200 V).
Application Diversity:
Energy efficiency has taken center stage in today’s electronics age giving traction to the development of SiC and GaN solutions. In comparison to silicon, SiC and GaN offer features such as high thermal conductivity, low conduction losses, high switching frequency, compact design with a low component count, and absence of any heat sinks giving rise to an energy-efficient device. High-voltage applications which leverage SiC include traction inverters for trains, motor drives for forklifts and conveyors, and grid-tie inverters. Comparatively, GaN has a wider application scope which encompasses power electronics, communication, and displays. In power electronics, GaN transistors are actively used in power adaptors for smartphones and laptops, power supply units for data centers, motor drives used in industrial robots, audio amplifiers, and microinverters for photovoltaic systems. GaN-based RFFE (radio frequency front end) systems are replacing silicon LDMOS (laterally-diffused metal-oxide semiconductor) devices in cellular infrastructure to support the frequency and power requirements of 5G communication. GaN-based micro-LED (light-emitting diode) display offers a perfect balance of high resolution, power efficiency, and compactness making it an ideal display for augmented reality (AR) and virtual reality (VR) devices.
The automotive sector is emerging as a key growth opportunity for SiC and GaN, especially the electric mobility segment. Traction inverters embedded with SiC MOSFETs will greatly increase the range of electric vehicles (EVs) while easing the transition to 800 V battery systems, a technical move aimed at reducing the charging time by half. GaN FETs will improve the power density of onboard chargers while GaN LIDAR (light detection and ranging) sensors will enable precision detection of obstacles and blind spots.
Key Stakeholders and Recent Innovations:
The innovation landscape in SiC and GaN revolves around the material structure, fabrication, substrate engineering, device architecture, advanced packaging, and end application implementation. At present, SiC is at the heart of research of all the EV OEMs (original equipment manufacturers) who are developing SiC-based motor drives and inverters while researchers and power electronics OEMs are focusing on developing SiC devices for ultra-high voltage (>10 kilovolts) applications. Tesla is one of the early adopters of SiC with around 48 SiC devices deployed in their high-end vehicles. CREE, Infineon, STMicroelectronics, Fuji Electric, and ROHM Semiconductor are the major global SiC transistor manufacturers. Significant improvements in performance and yield of GaN have been achieved by growing GaN on substrates such as SiC, silicon, and diamond as they make their inroads into RF (radio frequency), power converters, micro-LED displays, and SATCOM (satellite communication) applications. Qorvo, Wolfspeed, NXP, Transphorm, Navitas Semiconductor, VisIC Technologies, and Aledia are some of the prominent GaN companies across the globe. There has been growing interest in developing vertical GaN FET as it mitigates the existing voltage limitations of GaN and allows it to operate at higher voltages of 700 V and 1200 V. NexGen Power Systems (US) is pioneering the vertical GaN innovation through its vertical GaN enhancement mode Fin-junction FETs. Navitas’ (Ireland) unique product offering of GaNFast™ power integrated circuits (ICs) achieves monolithic integration of discrete GaN transistors with GaN drivers and other logic circuits. GaNFast™ power IC is being integrated into power adaptors of major smartphone and laptop manufacturers such as Lenovo, Xiaomi, OnePlus, Samsung, Motorola, and Dell. Aledia (France) has developed its proprietary WireLED™ micro-LED displays based on GaN-on-Si nanowire technology.
India’s first GaN HEMT was built at the Indian Institute of Science and has paved the way for the birth of Agnit Semiconductors, a GaN start-up that offers GaN wafers as well as GaN transistors for 5G and defense applications. Defence Research and Development Organisation (DRDO), India’s premier defense organization has developed GaN-based AESA (active electronically scanned array) radar called Uttam, which will be used in fighter jets such as Tejas and Sukhoi of the Indian Air Force.
Global Impact:
The COVID-19 pandemic has hit the nerve of the global semiconductor industry, which is the supply chain. North American and European countries have understood the severity of their reliance of Asian countries for semiconductor manufacturing and are taking drastic measures to mitigate the associated risks. The US and European Union (EU) are investing billions of dollars through their respective CHIPS Acts to consolidate the domestic semiconductor supply chain including that of SiC and GaN. However, the ongoing Russia–-Ukraine war might hamper these efforts, especially for the EU. The US-China trade war has ensured that Chinese companies are not entertained any bids toward a hostile takeover of semiconductor companies and hence curbing the technology transfer to China. Moreover, the looming security threat posed by Chinese telecommunication devices has resulted in the blacklisting of Chinese OEMs such as Huawei and ZTE for deploying their products for 5G in countries such as the US, UK, Sweden, Australia, and India. However, China has shown resiliency towards these setbacks and is building a strong domestic ecosystem for the growth of SiC and GaN with its prominent cities such as Wuhan, Changsha, and Guangdong offering subsidies to set up manufacturing hubs for SiC and GaN.
Japan and South Korea are renewing their semiconductor ties with Japan lifting the export restrictions for semiconductor materials and equipment. To summarize, SiC and GaN are identified as key semiconductors globally that will drive the developments in the next 5 years in mobility and communication sectors and hence are avidly sought out by developed nations.
Business Models, Business Strategic Points, and Concluding Points:
Manufacturing Gan and SiC devices is an expensive affair in comparison to manufacturing silicon as the materials and equipment are expensive and the fabrication process is complex. However, the growing prominence of GaN and SiC in today’s electronics industry has fueled investment in these two semiconductor materials. Major silicon foundries such as TSMC (Taiwan) and GlobalFoundries (US) are expanding their fabrication facilities to accommodate GaN fabrication. This move will greatly benefit companies adopting the fabless business model to engage with well-known foundries for product development. SiC has garnered huge investments from global semiconductor companies and automakers to consolidate the supply chain as the world sees a rapid increase in the adoption of EVs. CREE (US) has invested $1 billion for expanding the production capacity of its SiC foundry to process 200 millimeter (mm) wafers, which will greatly bring down the overall cost of SiC devices. Bosch (Germany) will be investing $1.5 billion towards the development of SiC devices for EVs through its recent acquisition of TSI Semiconductor. After acquiring DuPont’s SiC Wafer unit for $450 million, SK Siltron (South Korea) has started supplying SiC wafers for power electronics applications. In the meantime, as the race towards deployment of 5G is heating up, major RF firms such as Qorvo (US) and NXP (Netherlands) are increasing their production capacity. Infineon (Germany) will be acquiring Canadian GaN company, GaN Systems for $830 million to strengthen its GaN capabilities. Meta’s (US) partnership with Plessey Semiconductor (UK) will enable GaN-based micro-LED displays to enter mainstream AR as Meta gears up to launch its first AR glasses. Healthy partnerships, strategic mergers and acquisitions, and the introduction of the fabless business model define the present scenario of SiC and GaN.
However, SiC and GaN must cross many hurdles during their journey to growth. The existing wafer size for both materials is around 4 inches and 6 inches, which greatly curtails the production volume. Moreover, scaling up wafer size is getting complex as they are highly susceptible to defects. Hence, to achieve high-volume production and to bring down device costs, foundries must focus on developing 8-inch and 12-inch wafers. Unless the cost of SiC and GaN is brought down to that of silicon, their adoption will remain slow.
As the world is undergoing a rapid transition toward becoming a connected entity with the introduction of concepts such as artificial intelligence (AI) and the Internet of Things (IoT), the demand for energy efficiency is skyrocketing. Hence, it is an ideal time for SiC and GaN semiconductors to make an impact in the silicon-dominated electronics sector.
Authored by: Sushrutha Sadashiva, Industry Analyst, Frost & Sullivan
Blog received on Mail from Frost & Sullivan
