Delivering high-speed processing over 100 times faster than silicon, compound semiconductors have made the devices a magnet for developers of leading-edge technologies out to maximize performance in key segments including automotive, data centers and communications. With the rising profile of compound semiconductors as the backdrop, leading experts gathered at the Power and Opto Semiconductor Forum at SEMICON Taiwan 2022 to discuss the growing importance of the devices in chip innovation as the industry works to develop a robust compound semiconductor ecosystem. Following are key takeaways from the event.
Compounds Drive Innovation in Semiconductor Materials
Global trends such as electrification and sustainability are pushing power supply design engineers to find new ways to pack more power into less space while increasing device performance and reducing costs. “Wide-bandgap (WBG) semiconductors have arrived at just the right time as conventional silicon-based power ICs approach their physical limits,” said Power and Opto Semiconductor Forum speaker Luke Lee Vice, President of Asia and President of Texas Instruments Taiwan, Korea and South Asia.
Lee said Gallium Nitride (GaN) ICs can handle larger amount of power at a fixed size or power density through high efficiency and fast switching frequencies. In communications and data centers, where silicon-based and Insulated Gate Bipolar Transistor (IGBT) now dominate, GaN could be used to enhance channel density in test and measurement applications and boost the power density of energy storage systems since the ICs are effective in balancing device efficiency and costs.
With silicon reaching its performance limits, event speaker Simon T. Dann, President of IQE Taiwan, said new materials are key to addressing the technical challenges posed by megatrends such as the Internet of Things (IoT), autonomous driving, and the drive to net zero. The next generation of electronics innovation will be enabled by compound semiconductors that leverage new materials. The reason is that materials in compound semiconductors use a fraction of the energy that traditional materials consume to store, route, transmit, and detect data, powering the rising adoption of GaN and Silicon Carbide (SiC) to enable efficient, robust high-voltage applications.
The fast charger market for electric vehicles (EVs) is booming and has been behind the development of the power GaN ecosystem since 2019, opening the door to more WBG materials. GaN’s high efficiency and small size are ideal for automotive on-board chargers, data center power supplies and electric engineering applications, Dann said.
Hsien-Chin Chiu, Vice President of Research and Development at Wavetek Microelectronics Corporation, pointed out that the performance and reliability demands of 5G infrastructure and low-earth orbital satellite (LEOS) market are fueling the growth of high-efficiency antenna arrays and power amplifiers. The trend has also driven the shift from Remote Radio Head (RRH) to Active Antenna System (AAS) technology for Base Transceiver Stations (BTS), as well as the move away from radio frequency (RF) front-ends with traditional a one-single, high-power amplifier transmitters to antenna/PA (phased array) architecture.
Market research firm Yole Intelligence projects the RF GaN device market will top US$2 billion by 2025, with growth driven chiefly by telecommunications, satellite, and defense applications.
Nicolas Muesgens, Senior Product Manager of Product Marketing Management at AIXTRON SE, predicted that power supplies and power inverters will continue to drive adoption of WBG materials as GaN is forecast to deepen its penetration in the silicon power markets. Material performance, costs, availability are key factors in sustaining the current rate of WBG adoption.
Great Potential in Data Center, Automotive and Communication Applications
Stephen Coates, General Manager Asia and VP of Operations at GaN Systems, said compound semiconductors are spurring the proliferation of GaN in data center and automotive applications because of their power supply efficiency and that the trend will be pick up speed as more compound semiconductors are developed and commercialized. Claire Szu Ma, Manager of Network Sourcing at CSCP department at Microsoft, echoed Coates, explaining: “Network in data center is the point of traffic aggregation and is mission critical. The network that gears with its dedicated hardware ecosystem needs to continue exploring new technology to fuel growth. What the network needs is collaboration between Si-based IC solution and III-V based optics solution so the bandwidth can keep growing at the desired speed.”
“Semiconductors are the core of innovation in today’s automobiles,” said Edwin Chew, Manager of Regional Product Marketing at KLA Corporation. “Automotive ICs are subjected to even more stringent reliability standards than other semiconductor applications. Safety is the top priority, followed by function and performance, making chip reliability critical to both vehicle safety and function. Power devices used for automobile applications should conform to the same stringent quality standards as other automotive ICs.”
When it comes to communication applications, Chuck Huang, Sr. AVP in the Marketing Center at WIN Semiconductors, said: “With the obvious advantages of high frequency, high power, better efficiency and luminescence, compound semiconductors are changing the way we live. They not only are a part of the RF solutions from early cellular to 5G communications, but are also used to develop optical applications in sensing and communication applications. Current advances in augmented reality and virtual reality, autonomous driving, and metaverse applications will drive the next wave of compound semiconductor innovation.”
Compound Semiconductor Technology and Market to Forge Ahead
Ke-Horng Chen, Chair Professor of the Department of Electronics and Electrical Engineering at National Yang Ming Chiao Tung University, said monolithically integrated chips fabricated from depletion-mode GaN (dGaN) and enhancement-mode GaN (eGaN) devices have recently been developed. Continuous GaN processes and design techniques are key factors to ensuring monolithically integrated GaN solutions are viable. However, figuring out how to develop the solutions to replace MOSFET has become a challenge due to GaN process deficiencies.
The chief problem is that current trapping effects, self-heating issues and back gating effects degrade overall GaN chip performance in high-power density solutions, Chen said. The key to overcoming that barrier in developing monolithically integrated GaN solutions is to incorporate a temperature compensated (T-compensated) controller along with fast turn-on (FTO), metastable fast (MSF) comparison, pre-driving and desaturation techniques for integrating a 650V eGaN power switch.
Oxford Instruments Plasma Technology specializes in pGaN HEMTs and GaN MISHEMTs, focusing on atomic layer processing solutions to create next-generation GaN power devices. The company’s designers of pGaN HEMTs and GaN MISHEMTs solutions are adopting forward-looking technologies for atomic layer deposition of low-damage, high-quality dielectrics and passivation layers for accurate, controlled atomic layer etch.
Klaas Wisniewski, the company’s Executive Director, said atomic scale processing production solutions can enhance GaN HEMT performance for power electronics applications. He emphasized that GaN HEMTs for power electronics will become a billion dollar industry by 2030. And in some very high-growth markets, such as autonomous vehicles and data centers, various component geometries and production techniques will enable power semiconductors that are more efficient, smaller, lighter and lower cost and can operate at higher temperatures.
Mikko Söderlund, Head of Semiconductor ALD Sales at Beneq, noted that GaN-based technologies are pervasive in power devices and ICs, RF devices, LEDs and MicroLEDs. GaN materials with direct bandgap has made possible applications such as daylight-visible full-color LED displays, white LEDs and blue laser devices. The more recent extension to MicroLED technologies and the advent of GaN-on-Si are supporting a technology inflection toward higher brilliance displays, he said. Very high breakdown voltage, high electron mobility and saturation velocity of GaN has also made GaN-on-Si an ideal material for high-power and microwave applications. Furthermore, enhancement-mode GaN transistors are enabling another technology inflection, this one from power MOSFETs to GaN HEMTs for higher switching speed or power conversion efficiency.
Claire Troadec, Division Director of Power & Wireless at Yole Intelligence, said Taiwan has made notable achievements in developing SiC, GaN, GaAs and InP for compound semiconductors over the past few decades, and each material has penetrated mass markets in the power electronics industry including automotive and consumer. The adoption of these materials in the industrial, energy and communications markets is poised to spur further compound semiconductor growth.
To close the forum, Hao-Chung Kuo, Director of Semiconductor Research Center at Hon Hai Research Institute, stressed that compound semiconductors will become indispensable to future innovations and applications. “In addition to its own plans for future business development, Hon Hai vows to do its utmost to support the promotion of related technologies and projects in Taiwan and the technology industry and looks forward to growing together with the industry chain,” he said.
Executives presented at the Power and Opto Semiconductor Forum at SEMICON Taiwan 2022. Left to right: Dr. Nicolas Muesgens, Senior Product Manager, AIXTRON SE; Mr. Ian Wright, VP Sales Business Development Asia, Oxford Instruments; Mr. Luke Lee, President of Korea, Taiwan and South Asia, Texas Instruments; Mr. Brian Lee, CSO, Win Semiconductors Corp.; Ms. Claire Troadec, Power & Wireless Division Director, Yole Group; Mr. Stephen Coates, General Manager (Asia) & VP Operations, GaN Systems Inc.; Dr. Barry Lin, CTO, Wavetek Microelectronics Corporation; Mr. Gary Huang, Managing Director of Taiwan, Infineon Technologies Taiwan; Dr. Hsien-Chin Chiu, Vice President, Research and Development, Wavetek Microelectronics Corporation; Dr. Hao-Chung Kuo, Director of Semiconductor Research Center, Hon Hai Research Institute (Foxconn); Mr. Edwin Chew, Regional Product Marketing/Applications Manager, KLA Corporation; Ms. Jo-Ann Su, Senior Director, SEMI.
Ashley Huang is a senior marketing specialist at SEMI Taiwan.