Compound semiconductors for 5G, radar, electronic warfare, aviation, and satellite communication applications

Rajesh Uppal April 23, 2023 Electronics & EW, Nanotech, Photonics Comments Off on Compound semiconductors for 5G, radar, electronic warfare, aviation, and satellite communication applications 301 Views

Modern electronic products, from computers to smart phones, use silicon chips at their heart. As the name suggests, these chips are made from silicon, which is a highly abundant element found in sand. With a single element, it is possible to scale-up the manufacturing process to make highly complex silicon chips in large volumes, and hence 80% of the world’s semiconductors use silicon.

Until recently, Si was the most cost-efficient semiconductor material, and it sufficiently met the needs of power semiconductor devices. However, emerging applications like electric and hybrid vehicles (EV/HEV), rapid charging devices for mobile devices and EVs, and the 5G network need power devices that operate at higher frequencies, can handle higher voltages, are more thermally conductive, and can endure a broader range of temperatures.

20% of world’ semiconductors now use compound semiconductors, which combine two or more elements from the periodic table to form a compound. For example, silicon (Si) and carbon (C) form silicon-carbide (SiC). Some of the more common compound semiconductors include: gallium-arsenide (GaAs), gallium-nitride (GaN), silicon carbide (SiC), indium-phosphide (InP) and even aluminium-gallium-indium-phosphide (AlGaInP).

Although compound semiconductors are more complex to manufacture than silicon, they possess 3 properties that outperform silicon:

Power (power electronics for electric vehicles)
Speed (radio frequency for 5G and RADAR)
Light (photonics for optical fibre communications)

Their unique properties mean that compound semiconductors are finding increasingly diverse applications, such as:

Electric vehicles: range extension requires highly efficient SiC.
5G: GaN chips provide high speed data links for 5G.

Compound semiconductor classification

They can be categorized into III–V compound semiconductors, II–VI compound semiconductors, sapphire, IV–IV compound semiconductors, and others. The III–V compound semiconductors segment is further divided into gallium nitride (GAN), gallium phosphide (GAP), gallium arsenide (GAAS), indium phosphide (INP), and indium antimonide (INSB).

The II–VI compound semiconductors are classified into cadmium selenide (CDSE), cadmium telluride (CDTE), and zinc selenide (ZNSE). The IV–IV compound semiconductors segment is bifurcated into silicon carbide (SIC) and silicon germanium (SIGE). The others segment includes aluminum gallium arsenide (ALGAAS), aluminum indium arsenide (ALINAS), aluminum gallium nitride (ALGAN), aluminum gallium phosphide (ALGAP), indium gallium nitride (INGAN), cadmium zinc telluride (CDZNTE), and mercury cadmium telluride (HGCDTE).

Compound semiconductors provide significant performance advantages that are absolutely essential for a growing range of technology applications. Compound semiconductors such as GaAs and InP can operate at speeds that have higher magnitudes than silicon. In addition, compound semiconductors can generate and receive a broad range of the electromagnetic spectrum from high frequency ultraviolet visible spectrum to long wavelength infrared light.

When compared with Si, both SiC and GaN exhibit: Higher frequency and bandgap, Better electrical breakdown field, Better thermal conductivity, Higher temperature endurance and a wider temperature operation range

Other properties offered by compound semiconductor materials include the ability to emit and sense light in the form of general lighting (LEDs) and communications (lasers and receivers for fiber-optics). In recent years, InGaN has been attracting attention as a material for blue LEDs and laser diodes, and SiC and GaN as materials for power semiconductors have been noted and commercialized.

“We are seeing more and more adoption of higher-power-density GaN [gallium nitride] on SiC [silicon carbide] HEMTs [high electron mobility transistors] and MMICs [monolithic microwave integrated circuits] in the military and aerospace sector in the Ku band, Ka band, L, S, and C bands for radar, electronic warfare, aviation, and satellite communication applications,” Vampola says. The trend is being driven with the need for higher-output powers for these applications to drive longer distances, as well as new applications such as LEO satellite communication for broadband internet access. The ICP2840, Microchip’s flagship product for 5G and satellite communication, has output power of 10 W with power-added efficiency (PAE) of 22% and gain of 22 dB, he adds.

Si vs. SiC vs. GaN

Like Si, SiC is grown in ingot form before being sliced into wafers. However, while Si ingots can grow in one to five minutes, it can take three to four weeks to grow a SiC ingot. That’s why SiC costs more to manufacture than Si. However, through technology innovation, that’s being reduced to one to two weeks. Unlike Si and SiC, GaN is not grown in ingots. The wafers are formed by depositing a thin film on a silicon wafer.

Both SiC and GaN devices are available on 4- and 6-inch wafers. To increase yields to meet growing demand for these compound semiconductor materials, some companies are developing 8-inch wafer capabilities.

While SiC and GaN offer some of the same advantages over Si, SiC is more complex to manufacture. Because SiC withstands higher temperatures and has a wider bandgap than GaN, devices built from it can handle having 800 volts run through them. For this reason, Tesla chose SiC over GaN for its network of EV charging stations.

Despite the overall performance advantages, processing SiC device wafers poses some challenges that manufacturers don’t face when working with Si. For example, SiC wafers are transparent, which makes handling, marking, and metrology challenging. Wafer thickness and tendency to bow create challenges for maintaining flatness. They require thick metal deposition and extremely high temperatures (1800°C) for annealing. Lastly, there is no perfect design.

Military applications

Semiconductors for commercial and military applications are not necessarily mutually exclusive. Electronic components in sophisticated military systems use many of the same logic and memory chips that appear in consumer electronics. For example, field-programmable gate arrays (FPGAs) are frequently used in military systems due to their low-cost and high modularity. However, there are military-specific requirements that call for semiconductors with certain features. While commercial chip production is heavily driven by cost and timely, large-scale production, the defense sector’s demand for chips emphasizes performance. Namely, military-specific chips must be more durable and reliable, have a higher heat tolerance, and in some cases, be radiation tolerant.

As such, many military-specific chips contain compound semiconductors, which have superior electronic properties such as high electron mobility and direct band gap compared to silicon-only based semiconductors. Specifically, gallium arsenide (GaAs) and gallium nitride (GaN)-based chips appear most frequently in military-specific applications. Radio-frequency integrated circuits (RFICs) and monolithic microwave integrated circuits (MMICs) use GaAs and GaN technologies for a wide range of defense and aerospace uses. These include electromagnetic spectrum operations, signals intelligence, military communications, space capabilities, radars, jammers, and more.

In Jan 2022 it was reported that U.S. military microelectronics experts plan to build a 161,000-square-foot advanced compound semiconductor laboratory and microelectronics integration facility for multi-wavelength sources, large-format multi-wavelength detector arrays, RF and microwave electronics, high-power electronics, and integrated photonics.

Compound Semiconductor Market

The global compound semiconductor market was valued at $89.9 billion in 2019, and is projected to reach $212.9 billion by 2027, registering a CAGR of 11.1% from 2020 to 2027. The SiC market alone is predicted to reach $1.8 billion in that timeframe, and the GaN market is expected to be worth $24.9 billion by 2026.

A compound semiconductor is defined as a semiconductor composed of elements from two or more different groups of the periodic table, and is synthesized using deposition technologies. Devices made of semiconductors are essential components of most electronic circuits, as they possess unique properties such as wide band gap, high operational temperatures, high current & voltage holding capacity, and ability to generate microwave signals.

The compound semiconductor wafers are used in photonics, microelectronics, spintronics, and photovoltaic, among others. They provide faster switching at high power with increased energy efficiency and promote improved performances.

The Global Indium Phosphide Compound Semiconductor Market size is expected to reach $7. 6 billion by 2027, rising at a market growth of 9. 7% CAGR during the forecast period. The binary semiconductor indium phosphide (InP) is made up of two elements: indium and phosphorus.

The most important and critical application of indium phosphide (InP) compound semiconductor nowadays is in fibre optic communications. Because InP can emit and detect wavelengths over 1000 nm, high-speed fibre optic communication dominates the InP Wafer. InP wafers are used in high-power, high-frequency optoelectronic devices such as laser diodes, photodetectors, LEDs, and optical transceivers in optical fibre communication systems. Manufacturers are introducing advanced communication technologies by using InP semiconductor, which would fuel the growth of the market over the forecast period

Epitaxial wafer is manufactured by adding multi-micrometer thick single silicon carbide crystal layers on top of a polished wafer. Precise control of thickness, carrier concentration, and defect density is required to enable its seamless production. The epitaxial layers define the wireless, photonic, and electronic performance of compound semiconductor epitaxial wafers, which are then processed to produce the chips and ICs, which can be found in various technology devices and gadgets globally.

The factors such as advantage of compound semiconductor wafers over silicon-based wafers, increase in demand for compound semiconductor epitaxial wafer in consumer electronics, and emerging trends toward wafers in automotive industry drive the compound semiconductor market growth to a certain extent. However, increase in cost of wafer manufacturing is expected to pose a major threat to the compound semiconductor market size globally. However, emerging usage of compound semiconductors in smart technologies and increasing popularity of IoT in wafers are expected to provide lucrative compound semiconductor market opportunity globally.

By deposition technology, the compound semiconductor market share is segmented into chemical vapor deposition (CVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), ammonothermal, liquid phase epitaxy (LPE), atomic layer deposition (ALD), and others. On the basis of product, compound semiconductors are categorized into power semiconductor, transistors, integrated circuits (ICs), diodes & rectifiers, and others.

The transistors segment is further classified into high electron mobility transistors (HEMTs), metal oxide semiconductor field effect transistors (MOSFETs), and metal semiconductor field effect transistors (MESFETs). Integrated circuit is bifurcated into monolithic microwave integrated circuits (MMICs) and radio frequency integrated circuits (RFICs). The diode & rectifiers segment is further segmented into PIN diode, Zener diode, Schottky diode, and light emitting diode

On the basis of applications, the market is studied across IT & telecom, industrial and energy & power, aerospace & defense, automotive, consumer electronics, and healthcare. IT & telecom is further segmented into signal amplifiers & switching systems, satellite communication applications, radar applications, and RF. Aerospace & defense is classified into combat vehicles, ships & vessels, and microwave radiation. Industrial and energy & power is further segmented into wind turbines and wind power systems.

Consumer electronics is further segmented into inverters, LED lighting, and switch mode consumer power supply systems. The automotive segment is further divided into electric vehicles & hybrid electric vehicles, automotive braking systems, rail traction, and automobile motor drives. The healthcare segment is further bifurcated into implantable medical devices and biomedical electronics. By region, the compound semiconductor market is analyzed across North America, Europe, Asia-Pacific and LAMEA, along with its prominent countries.

Taiwan plays a central role in global compound semiconductor manufacturing. To illustrate, Taiwan’s WIN Semiconductors holds 9.1 percent of the total GaAs device market share, third in the world behind American firms Skyworks (30.6 percent) and Qorvo (28.6 percent). But in terms of pure-play GaAs foundry revenue, WIN Semiconductors holds by far the largest share at 79.2 percent. The next three firms are Tainan-based AWSC (8.6 percent), California-based GCS (4.2 percent), and Hsinchu-based Wavetek (3.4 percent). Together, the top three Taiwanese firms hold over 90 percent of the GaAs foundry market.

United States has done well to keep critical defense-related compound semiconductor manufacturing onshore and, in many cases, in-house. Many U.S. defense primes, such as Raytheon and Northrop Grumman, and other contractors maintain their own foundries, most of which are certified as trusted suppliers to the U.S. government as part of the Department of Defense’s Trusted Foundry Program. An American stronghold over power and analog semiconductor devices is the primary reason why manufacturing in this case has been kept onshore. Today, the largest U.S. manufacturer of GaAs semiconductors, Skyworks, while maintaining its own fabs, is to a degree reliant on Taiwan’s WIN Semiconductors for its foundry services.

The key compound semiconductor industry players include Cree Inc., Nichia Corporation, Samsung Electronics, Qorvo, NXP Semiconductor N.V., Taiwan Semiconductor Manufacturing Company Ltd., Renesas Electronics Corporation, Texas Instruments Inc., STMicroelectronics NV, and Infineon Technologies AG. These key players have adopted strategies, such as product portfolio expansion, mergers & acquisitions, agreements, geographical expansion, and collaborations to enhance their market penetration.