Academician Zheng Youzhu: Third generation semiconductors usher in new development opportunities

Similarly, the development needs of information technology and electronic information technology industries have driven the development of semiconductor materials and technology

Third generation semiconductor materials and their applications

Third generation semiconductors refer to those represented by GaN and SiCWide bandgap semiconductor materialsIt is a new type of wide bandgap semiconductor material developed in the 1990s, following the first generation semiconductors represented by Ge and Si in the 1950s and the second generation semiconductors represented by GaAs and InP in the 1970s. It is a semiconductor material with a bandgap width significantly larger than that of Si (1.12 eV) and GaAs (1.43 eV), usually defined asMaterials with a bandgap width greater than 2 eV.

There are currently three types of materials that are highly concerned（1) III group nitride semiconductorIncluding GaN (3.4 eV), InN (0.7 eV), AlN (6.2 eV) and their solid solution alloy materials; （2）Wide bandgap IV compoundsSiC (2.4-3.1 eV) and diamond thin film (5.5 eV) materials; （3）Wide bandgap oxide semiconductorZnO, ZnMgO, ZnCdO materials including Zn based oxide semiconductors (2.8~4.0 eV) and gallium oxide (β - Ga)₂O₃ 4.9 eV）。 GaN and SiC materials have been successfully applied in many industrial fields

existOptoelectronics fieldBased on the excellent optoelectronic properties of GaN, InN, AlN and their formed solid solution alloys with direct energy gaps of all components, we have developedEfficient solid-state light-emitting light sourceandSolid state ultraviolet detection deviceBy filling the gap in short wavelength semiconductor optoelectronic technology, it has opened up a new era of white light illumination, transcendental illumination, full-color LED display, and solid-state ultraviolet detection. After nearly 20 years of development, the technology has become increasingly mature and the industry has flourished, achieving tremendous successScientific, economic, and social benefitsIn 2019, the market size reached 638.8 billion yuan

existelectronics fieldBased on the superior electronic properties of materials such as wide bandgap, high electron saturation velocity, high breakdown electric field, high thermal conductivity, and low dielectric constant of GaN and SiC, high energy efficiency, low power consumption, high extreme performance, and resistance to harsh environments have been developedNew generation microwave RF devices(GaN) andPower electronic devices（SiC, GaN）。

GaN RF devicesCompared with GaAs, it has higher operating voltage, higher power, higher efficiency, higher power density, higher operating temperature, and more radiation resistance

Power electronic devicesCompared with Si, it has higher operating voltage, high power density, high operating frequency, low on state resistance, extremely low reverse leakage current, and high temperature and radiation resistance characteristics

New opportunities in the era of new infrastructure construction

Currently, China is vigorously implementing 5G communication, Internet of Things, big data, cloud computing, and artificial intelligenceNew generation information technologyThe transformation and upgrading of vertical industries such as high-speed rail networking, industrial networking, intelligent manufacturing, smart energy, smart cities, medical health, and rail transitNew infrastructure construction(New infrastructure), promoting innovative and high-quality development of China's economy and society

New Infrastructure Needs in the 5G EraFollowing the development opportunities characterized by the LED semiconductor lighting industry in response to the global energy and environmental development strategy at the beginning of the 21st century, it has also ushered in the development opportunities characterized by the third-generation semiconductor electronic technology industryA new round of new development opportunities.

The third generation of semiconductor electronic technology is characterized by itsenergy efficient, low-power consumption, High Extreme PerformanceandResistant to harsh environmentsThe irreplaceable advantages play an important supporting role in the development of 5G information technology and the implementation of new infrastructure from the technical bottom in the fields of microwave radio frequency and power electronics

RF devicesIt is the core foundational component of RF technology, serving asRF power amplification, Active RF switchandRF power sourceHas broad application prospects

GaN RF devicesCompared to traditional silicon horizontalCompared with diffused metal oxide semiconductor (Si LDMOS) and GaAs devices, it has the advantages ofHigher operating voltage, higher power, higher efficiency, higher power density, higher operating temperature, and greater radiation resistanceThe advantages of this technology support the implementation of new infrastructure, from the application of advanced military electronic equipment such as radar, electronic countermeasures, navigation, and space communication to a wide range of civilian fields such as 5G base stations, the Internet of Things, laser radar, unmanned vehicle millimeter wave radar, artificial intelligence, and general solid-state RF power sources. It is expected to open up a huge consumer electronics market and has the potential toReshaping the New Pattern of RF Technology Development.

For exampleGaNRF devices as5GBase station RF power amplifier（PA）The core components solve the problems faced by base station communication systemsHuge energy consumption bottleneck triggeringGaNThe demand for RF devices has exploded

5G macro base stations operate in the high frequency range, with high losses and short transmission distances. To achieve the same coverage target as 4G signals, 5G base stations will require 3-4 times the number of 4G base stations (currently 4.45 million in China). To increase network capacity, 5G base stations use massive array antenna technology (MIMO), with a single base station PA requirement of nearly 200 64 channel MIMO array antennas. Therefore, the power consumption of 5G base stations is 3-4 times that of 4GThe overall energy consumption of 5G base stations will be more than 9 times that of 4G.

Therefore, GaN RF devices have become an inevitable choice for 5G base station PA due to their irreplaceable advantages, and are also the mainstream direction for upgrading 4G base station PA; The implementation of new infrastructure has opened up opportunities for GaN RF devices in the radar fieldWide range of civilian application scenarios.

GaN millimeter wave radar hasThe characteristics of small size, light weight, high resolution, strong ability to penetrate smoke, fog, and dust, and long transmission distanceIt will be widely used in many fields such as the Internet of Vehicles, the Internet of Things, intelligent manufacturing, and smart society. For example, the GaN millimeter wave radar in the 77 GHz band is used as a remote detector for autonomous vehicle to accurately sense surrounding obstacles to achieve automatic emergency braking, adaptive cruise, forward collision warning, etcFunctions in the field of active safety.

Power electronic devices areElectricity conversion and managementThe energy efficiency of the core components determines the energy consumption, volume and mass size, cost and reliability of electronic systems, equipment and products, as well as the battery life of intelligent mobile terminals

The demand for power electronic devices in modern electronic systems or equipment is increasing, requiring not onlyHigher power densityandHigher energy efficiencyAnd it is required to haveHigh Extreme CharacteristicsandPerformance resistant to harsh environmentsTraditional Si power electronic devices have low conversion efficiency and require huge energy consumption. Moreover, the improvement of device performance such as blocking voltage, switching frequency, conversion efficiency, and reliability is gradually approaching the physical limit of Si materials, facing severe challenges

SiC and GaN power electronic devices have excellent characteristics beyond Si devices, which can meet the new needs of 5G information technology infrastructure, solve the huge energy consumption bottleneck faced by information infrastructure such as data centers and wireless base stations, and support the implementation of IT mobile intelligent terminalsMiniaturization, lightweighting, and improved battery lifeSupporting new energy vehicles, smart energy, rail transit, intelligent manufacturing, etcNew infrastructure advantages, application areas, industrial developmentThe urgent need

SiC and GaN power electronic devices due to theirDifferences in electrical properties of materialsSuitable for different power application scenarios: SiC power devices are used for high-voltage and high-power power management, such as new energy vehicles and their charging infrastructure, new energy power inverters, and smart energy systems

According to test data reports, the use of SiC power module inverters in new energy vehicles can reduce switch losses by 75% (chip temperature of 215 ℃), decrease inverter size by 43%, and reduce weight by 6 kg, enabling the continuous range of the vehicleIncrease by 20%~30%.

China is the world's largestNew energy vehiclesIn 2019, the sales of new energy vehicles in China reached 1.16 million units, accounting for 54% of the global market. The market for automotive power devices has seen significant growth, bringing benefits to the SiC power electronic device and module industryHuge development spaceGaN power devices have extremely broad application prospects in the field of consumer electronics for low-voltage and high-frequency power control

Especially based on its excellent performance of high operating frequency, low dynamic loss, low on resistance, high temperature resistance, and low heat generation, it is highly suitable asApplication of Switching Power SupplyTo provide various modern consumer electronic terminals withGreen and efficient power supply.

For example, as a fast charging power adapter, it solves the contradiction of increasing power and volume in Si devices to achieve fast charging, resulting in power loss and size of the power supplySharp decrease by 50%Not only can it shorten the charging time of mobile phones and effectively improve their battery life, but it is also expected to achieve various functions such as mobile phones, tablets, game consoles, AR glasses, VR helmets, etcIntegrated charging of mobile terminalsSupporting the development of portable IT terminal products has become a trend in the current GaN power electronics industry, and it is expected that the global GaN fast charging product market will reach over 60 billion yuan by 2025

Compared with SiC, GaN power devices have faster switching speed, lower on state resistance, smaller driving loss, higher conversion efficiency, and lower heat generation. In addition, Si based GaN devices have the advantage of lower cost. Therefore, GaN power electronics technology is not only widely used, but also has a wide range of applicationsConsumer electronics fieldAnd in various new infrastructure projectsMedium and low voltage application scenariosIt has extremely broad application prospects

outlook

In the era of 5G information technology, the third generation of semiconductors has ushered in new development opportunities. The implementation of new infrastructure has helped the development of the third generation semiconductor industry enter a golden window period, showing a good momentum of development, which is expected to gradually realizeAutonomous and controllable, safe and reliableThe third generation semiconductor industry system, along with the first and second generation semiconductorsComplementary advantages and collaborative supportThe innovative development of new generation information technology supports the high-quality development of China's social economy in the new era