Driven by the promotion of fast charging applications, the GaN (Gallium Nitride) market has been soaring since 2020, presenting significant business opportunities in the power device and RF (Radio Frequency) markets. Previous articles by Jiwei Consulting, such as “Jiwei Consulting: GaN Fast Charging Reaches Sweet Spot, Bringing More Killer Applications to the Medium-Low Voltage Market,” analyzed the rise of GaN technology from a slump to a steady climb, emphasizing its bright prospects in the medium-low voltage device market. With an increasing number of companies entering the competition, the GaN sector is experiencing intensified competition. This article aims to analyze future contenders in the field from a patent perspective.
Global GaN Industry Landscape:
The global GaN industry has now formed a preliminary structure, encompassing upstream raw materials (substrates, epitaxial wafers), midstream GaN manufacturing (GaN chip design, manufacturing, packaging and testing), and downstream GaN applications (power electronic devices, RF devices, optoelectronic devices). GaN technology has found widespread applications in power devices, RF devices, and optoelectronic displays. According to Market and Market data, the major classifications of global GaN devices in 2020 were GaN optoelectronic devices, GaN RF devices, and GaN power electronic devices. From a segmented market perspective, GaN optoelectronic devices had the highest market application rate at 65.22%, followed by GaN RF devices at approximately 29.89%, while the market size for GaN power electronic devices was the smallest, accounting for only 4.89%.
GaN Technology from a Patent Perspective:
Global Distribution and Innovation Focus of GaN Patents
Since the first patent application in the 1970s, the global GaN industry has accumulated over 160,000 patent applications, with more than 60,000 valid patents. Invention patents and technological innovations have been particularly active. Based on data retrieved from Wisdom Yago, GaN technology was in its early stages of academic research and exploration before 1994, with limited corporate participation. From 1994 to 2005, it experienced the first wave of development, primarily applied in LED lighting. The growth of GaN patents from 2010 to 2014 was concentrated on breakthroughs in substrates by Japanese companies such as Sumitomo and Hitachi and further productization. After 2014, GaN patent applications continued to grow steadily, maintaining an annual application volume of over 9,000, with LED/MicroLED optoelectronic devices, GaN-based FET devices, and GaN power/RF devices becoming hotspots in patent applications.
GaN Technology Sources and Distribution:
In terms of the distribution of GaN technology sources, Japan and the United States initiated GaN research in the 1970s, holding the majority of GaN-related patent reserves.
Currently, Japan is the largest contributor to global GaN technology, accounting for 35.5%, followed by the United States at 22.95%. Mainland China ranks third with 14.54%, slightly higher than South Korea’s 14.2%. These four regions collectively contribute to over 87% of GaN patents. Despite Japan and the United States having a nearly 20-year head start, with Japan notably leading until 2010, Mainland China began to exert its influence from 2010 onwards, maintaining rapid growth and gradually taking a leading position in GaN patent applications. The advantage is evident, with China’s GaN patent application numbers consistently surpassing other regions.
Despite the United States having a patent layout nearly 20 years earlier than Mainland China, its development trend has been relatively steady over the past decade. China initiated relevant patents in 1985, but the number of patent applications increased rapidly and surpassed the United States after 2011.
Looking at the main entities applying for GaN patents globally, the leading innovators are primarily concentrated in Japanese patent applicants. However, applicants from Mainland China have shown exceptional activity in recent years, indicating a continuous increase in research and development investment in the GaN field. The number of related enterprises and research institutions in China is also continually rising. Additionally, overseas applicants with a presence in China are primarily Japanese companies, including Mitsubishi Electric, Sumitomo, and Panasonic.
From 2010 to September 2021, the Concentration Ratio of the top 10 global GaN patent applicants (CR10) exhibited a fluctuating trend. It remained above 13% from 2010 to 2020 and increased to 17.18% in 2021. Overall, the concentration of global GaN patent applicants is not high (Note: CR10 represents the proportion of patent applications from the top 10 applicants in terms of total patent applications in the field. When there are joint applications, the patent count is not deduplicated). The key global patent applicants are concentrated in Japanese companies, aligning with the fact that Japan is a major source of GaN technology. There is a significant gap in GaN technology reserves between Chinese enterprises and overseas leaders(sources from medcom.com.pl
Distribution of GaN Patent Technologies:
Regarding the distribution of GaN patent technologies among the top 10 applicants by the number of applications, the largest reserve of patents belongs to the classification H01L33, which relates to optoelectronic devices. Most patents are also concentrated in the electrical field, primarily because GaN is a crucial semiconductor material for enhancing the performance of power electronic devices and RF devices, with increasingly significant applications in areas such as power electronics and RF chips.
Furthermore, among the top 10 GaN patents with the highest global market value, seven patents have a value exceeding $10 million. The patent with the highest value, at $11.46 million, belongs to LG Innotek Co., Ltd., with patent number “EP2863444B1.” This patent proposes a method for manufacturing vertical structure GaN-based LED devices on a sapphire substrate using a metal support layer.
GaN Innovation Focus and Directions
Analyzing the GaN patent application heatmap, global GaN technology innovation has primarily focused on three major areas: Substrates, GaN HMET Devices, and Micro LED.
Substrate Technology:
Substrate technology is a key breakthrough for reducing the cost of GaN devices, transitioning from small-scale and small-size applications to large-scale commercialization, larger sizes, and higher crystal quality.
Currently, there are over 13,000 global GaN substrate-related patents, with more than 4,800 valid patents. Japanese companies dominate in substrate technology patents, with Sumitomo Corporation and Mitsubishi Chemical Corporation leading. Other notable applicants include Shin-Etsu Chemical and CREE.
Current GaN substrate technologies include GaN single crystal substrates, GaN-on-SiC, and GaN-on-Si.
In terms of innovation, the patent distribution indicates significant research in GaN single crystal growth techniques. Popular growth techniques include HVPE (Hydride Vapor Phase Epitaxy), which is a mature single crystal growth technology. Solvent-assisted methods and ammonia-based methods have gained attention in the last decade. Recent research focus in substrate processing includes grinding and polishing, cutting and chamfering, and substrate delamination.
Additionally, GaN heteroepitaxy has achieved industrialization on 6-inch wafers, gradually progressing towards 8-inch wafers. Innovations in this area focus on large sizes and high-quality substrates. For instance, in 2020, Tsinghua University proposed a method using a polishing composition to polish GaN material, involving purified silicon sol abrasive, a corrosive agent, an oxidizing agent, a promoter, and water (patent number CN106398544A). Suzhou Nano Simulation Institute/Suzhou Navi Technology proposed a method to promote seed crystal liquid-phase epitaxy using a solvent-assisted method, adding a carbon additive during the growth process to effectively reduce seed crystal dissolution in the early stage of GaN crystal growth (patent number CN107687022A).
Automotive-Grade GaN Power Electronic Devices:
With the growth of the electric vehicle market, automotive-grade GaN power electronic devices have become a research hotspot, moving towards multi-unit modularization.
In the electric vehicle sector, EPC and Transphorm have automotive-grade GaN power electronic devices that have received automotive certification. The automotive industry increasingly recognizes and values GaN power electronic device solutions for electric and hybrid vehicles.
There are over 20,000 global patents related to GaN power electronic devices, with a valid patent rate of 45.61%. The United States, Japan, and China are hotspots for patent layout, with a particular emphasis on the U.S. market. Major patent applicants include Sumitomo, Fujitsu, Toshiba (primarily Japanese companies), CREE, and Intel.
In terms of innovation, GaN power electronic devices have progressed through stages such as substrate material selection and exploration of various new device structures (improvements to 2DEG structure, vertical/heterojunction fin structures, etc.). The current research focus is on combining multiple units to form multi-unit modules. For example, in 2021, CREE proposed a large effective gate width multi-unit transistor device (patent number US10483352B1), and Sanan Optoelectronics proposed a HEMT epitaxial structure with multiple quantum well high-resistance buffer layers (patent number CN108400159A).
Micro LED:
Due to its advantages such as self-emission, low power consumption, high brightness, ultra-high resolution, small size, and high color saturation, Micro LED has become the future direction of LED development.
Looking at the global patent application situation for Micro/Mini LED, there are currently over 2500 patents in this field, with more than 900 valid patents. China is the leading research contributor in this area, accounting for 40.78% of patent applications, led by major applicants such as Facebook (Meta), Apple, Goertek, BOE, and Sanan Optoelectronics.
Current innovations in Micro LED are mainly focused on breakthroughs in mass transfer technology. For example, in 2019, Apple proposed a beam addressing release (BAR) mass transfer technology to transfer multiple Micro LEDs at once (patent number US20200194616A1). In 2020, Samsung proposed arranging a transfer substrate between the target substrate and the laser oscillator, placing rows/columns of Micro LED devices of different colors on the transfer substrate, and irradiating a laser beam toward the target substrate to achieve mass transfer of Micro LEDs (patent number US20200335659A1).
Leading GaN Innovation Companies – Technical Analysis:
Sumitomo Corporation (Japan):
Sumitomo Corporation holds an absolute advantage in GaN patent reserves. Starting GaN-related patent applications in the 1970s, the company was the first to mass-produce GaN substrates in 2003 and high-performance GaN HEMTs in 2006. It is currently a major supplier of GaN RF devices globally, with a robust patent layout supporting its subsequent business success.
Sumitomo’s GaN technology reserves primarily focus on substrate and device research. Notably, patents related to visible LEDs, GaN-based FET devices, laser diodes, GaN single crystal growth techniques are abundant, with a recent emphasis on GaN-based FET devices in the last 5 years. In GaN-based FET devices, Sumitomo explores various technological directions, including epitaxy processes, chip processes, improving breakdown voltage, reducing leakage current, suppressing current collapse, and improving 2DEG structure. However, Sumitomo currently lacks patents related to improving structural defects and conduction characteristics(quotes from medcom).
It’s worth noting that Sumitomo’s GaN failure patents currently account for a high percentage, around 60%.
CREE (Wolfspeed, United States):
CREE is one of the early companies to focus on GaN and SiC technologies in the United States. Starting GaN-LED-related patent applications around 1991, the company experienced its first rapid growth in patent applications after introducing the first SiC-based GaN HEMT device in 1998. With the sale of its lighting and LED business in 2019 and 2021, CREE transformed into a company primarily focused on wide-bandgap semiconductor products, renaming itself Wolfspeed in 2021.
CREE mainly focuses on the GaN-on-SiC technology route, with more than 3000 patents in the GaN field, with a valid patent rate of nearly 52%.
After divesting its LED business, CREE shifted its GaN research focus to GaN-based FET devices. Currently, CREE has accumulated 696 patents in this field, with 430 valid patents. Its patent layout focuses on reducing leakage current, increasing breakdown voltage, improving linearity, enhancing the crystal quality of the GaN layer, reducing semiconductor etching damage, and reducing surface trapping effects. However, CREE’s patents in areas like increasing gain and extending lifespan are relatively lacking.
Infineon Technologies (Germany):
Infineon Technologies is a global leader in power semiconductor technology. Beginning around 1997, the company started applying for patents related to GaN laser diodes and GaN layer growth techniques. In 2014, through the acquisition of International Rectifier (IR), it gained Si-based GaN power semiconductor manufacturing technology, leading to a rapid increase in patent numbers, with a high patent grant rate. Currently, Infineon holds more than 1400 GaN-related patents, with an impressive 61.5% valid patent rate and high technological innovation.
Infineon focuses its GaN research on the midstream – device modules, including GaN-based FET devices and power modules integrated with multiple power elements (such as power converters). It holds the most patents in these areas. Key areas of focus include improving heat dissipation, reducing power loss, increasing operating voltage, reducing package size, reducing parasitic inductance and capacitance generated by integrated devices, and improving bidirectional switch characteristics. However, Infineon’s patents in areas such as short-circuit protection, overvoltage protection, and electrostatic protection are relatively lacking.
Sanan Optoelectronics (China):
As a leading LED company in China, Sanan Optoelectronics has accumulated certain technological reserves in the GaN field. In 2014, the company invested in the construction of a GaN high-power semiconductor project. In 2018, it invested 33.3 billion RMB in Fujian Quanzhou to develop industries such as Group III-V compound semiconductor materials, LED epitaxy, chips, microwave integrated circuits, optical communication, and radio frequency.
Sanan Optoelectronics is also concentrated on the midstream – the device module’s research. Its device types mainly include visible LEDs, UV LEDs, Micro/Mini LEDs, and GaN-based FETs. After 2016, Sanan Optoelectronics’ patent application volume for visible LEDs gradually declined, with a subsequent increase in patents related to Micro/Mini LEDs and GaN-based FETs.
As GaN technology matures into a steadily advancing bright period, patent activity related to GaN is becoming more and more active. With more players entering the field, the GaN patent landscape is continually evolving.
