Gallium nitride (GaN) is the ideal chip material for use in military applications. It outperforms conventional silicon because of its ability to operate at higher voltages and frequencies. But it doesn’t end there. It has other characteristics which the military men like, and these include its resistance to harsh environments and ability to withstand high temperatures.  

With these attributes, any country that can achieve a dominant position relative to the advanced design and consistent supply of GaN devices could well be rewarded by finding itself in a leading position when it comes to military strength. In a world where conflict seems to occur regularly, such a position is considered by many governments as highly desirable.  

So who is leading the charge at present? Clearly, it’s China, and it finds itself in this happy position because of a number of factors. 

The material used to manufacture GaN is gallium, and it is critically important that it is made to a very high standard of purity. Because of this stringent requirement, there are not many places it can be made, and China is proving to be particularly good at it and now produces approximately 67% of the global supply of germanium. 

Not only is China good at that, but it is also capable of very good GaN fabrication and has recently discovered, via research conducted by Peking University, one of the major causes of defects that can affect GaN. It has also researched how those defects can be avoided.  

Dislocation Defects 

Fabrication of GaN uses silicon and sapphire, and the research team found that dislocation defects can interfere with the crystal structure, which has a detrimental effect on device performance because it can adversely affect how well a semiconductor material is able to conduct electricity. 

What the research team did was to deliberately introduce impurities and increase the gate voltage, and this cut down the number of dislocations found in GaN fabrication. This could have the effect of not only increasing efficiency but also lowering the cost of GaN.  

So in military terms, this chip design work by China could enhance its strength by providing high-quality GaN technology at moderate prices. Bearing in mind its position of being the world’s most prolific producer of gallium, it would also hold the whip-hand on who gets the surplus it does not require for its own needs. 

If China can mass-produce high-quality GaN chips, it could increase its lead in semiconductor technology, especially in military and 5G applications. Since the US depends on GaN for military applications, these developments could increase China’s strategic advantage in electronics and defence, and obviously, America would not like that. 

Having said that, America does have considerable muscle when it comes to holding its own in the GaN market. It has a strong GaN fabrication base with major electronics companies supplying components for a large range of applications, not just military-related ones. It leads the world when it comes to semiconductor design and development expertise and is well recognised as a producer of very good chip production equipment. But it does have weaknesses when it comes to GaN. 

Long-Term Investment 

It is worrying for the US that China has created highly capable GaN technology companies like HiWafer, Innoscience and Sanan Integrated Circuits that are now considered right up there with global leaders. China has clearly signalled its ambition to become dominant in GaN semiconductors and is supporting this desire with substantial, long-term investment in chip R&D. 

But as mentioned previously, one difficulty for the US to consider relates to the raw material gallium that’s needed to make GaN devices. Its problem is that China is a huge supplier of gallium, but back in 2023, it introduced restrictions on the export supply of this essential mineral and made no secret of the fact that it did this with regard to national security. 

Market opinions and, to be fair, industry rumours, suggest that since that restriction was introduced, China has not exported gallium to the United States. If this is the case, then the gradual erosion of stocks in the USA will certainly impact the country’s ability to fabricate sufficient supplies of high-end GaN for its many military applications.  

Take, for example, its F-35 Lightning fighter jet. A superb combat aircraft which uses GaN technology. Its radar system, which is considered to be state-of-the-art, can jam enemy systems, track very small enemy aircraft at long distances and has extremely rapid signal transmission capabilities. Without GaN, the system’s effectiveness would be at risk. 

So industry analysts are asking if this is China weaponising its dominant world position on gallium raw material in an attempt to hinder other countries’ ability to build sufficient stocks of high-end, competitive, military-grade GaN devices? The answer would seem to be yes. 

If China plans to restrict the rest of the world from accessing necessary materials for advanced technological development, there is a pressing need for the United States to reinforce its gallium supply chain more actively. Accordingly, the United States should also prioritise and strengthen its high-tech research and related policies to successfully lead the next generation of semiconductor devices. 

What Should the US Do? 

To avoid falling behind China in the development of this critical technology, the United States needs to improve several elements of its domestic GaN ecosystem. Currently, the United States, along with the United Kingdom and Europe, leads the world in terms of technical capabilities related to GaN semiconductor technology.  

However, the United States needs to augment its technical lead with investments in the required materials and fabrication infrastructure in order to boost its position on GaN technology significantly. In other words, the United States should provide funding that will convert technical expertise into a volume product. 

In this regard, the US and its partners should increase domestic epitaxy capacity. Industry analysts believe the United States should further develop its skills in GaN manufacturing. Accordingly, the US must consider and introduce substantial investment in GaN epitaxy technology. 

It is fair to say the US Government has already made substantial investments into GaN fabrication plants, but the fact that the US does not have sufficient epitaxy capacity remains a critical issue. 

In addition to this, the US must resolve certain production difficulties in GaN fabrication. Gallium nitride on silicon can suffer from an inherent lattice mismatch that creates defects. It is also difficult to produce GaN substrates on which GaN crystals can be grown. Together, these issues with GaN make mass production complicated and expensive compared to silicon. This is where America’s design and development skills and its large investment reserves need to come in. 

But as previously mentioned one of the most worrying problems for the US when it comes to GaN production is securing the supply of gallium, particularly as the world’s largest producer of that, China is starting to play hard ball on restricting imports, particularly to those countries it deems as not only competitors in the global device market but potentially military opponents should conflicts break out.  

Could the answer lie in aluminium? Gallium is not a material that exists in mineral deposits. It is not a rare earth. It is, in fact, a by-product of aluminium production and zinc refining. 

While the United States is not a major producer of aluminium, important partner nations, including India, Australia, and Canada, are strong players in this industry. Indeed, all three nations are members of the Minerals Security Partnership, an initiative that coordinates initiatives aimed at stimulating critical mineral production in member nations.  

Import Tariffs 

The United States should consider this when it is discussing import tariff charges against countries that are strong producers of aluminium. For example, in 2023, Canada produced an estimated 3.3 million tonnes of primary aluminium. It is the world’s fourth-largest primary aluminium producer, following China and India. Perhaps the US should make sure it buddies up with its immediate neighbour regarding gallium? 

GaN’s unique qualities (e.g., higher speed, lower resistance, higher breakdown voltage) make it widely applicable to a diverse set of markets, allowing it to stand apart from silicon-based semiconductors. As such, these abilities underscore its potential to revolutionise strategic industries and bolster national security, especially in defence radar systems and power electronics.  

Unlike silicon fabs that require expensive lithography equipment, GaN chips can be manufactured on eight-inch wafers using legacy equipment. In other words, cutting-edge GaN technology can be produced using fabrication equipment that is obsolete for silicon. 

What about a replacement for GaN that would possibly neutralise or at least dilute any military advantages China would have through its GaN capabilities?  

What about GaN Alternatives? 

To meet the growing demands of advanced electronic systems, next-generation power and RF semiconductor devices must operate efficiently at higher power levels and switching frequencies while remaining compact.  

According to the Department of Materials & Metallurgical Engineering, Colorado School of Mines, USA, the current GaN semiconductor devices alone cannot meet all these demands. However, emerging ultra-wide band gap (UWBG) alternatives like diamond, BN, AlN, and Ga2O3 face significant challenges, including limited wafer availability, doping difficulties and thermal management constraints.  

To further investigate the implications of these design difficulties, the department conducted a full study, and this is what it concluded. 

The results of its high-throughput screening were seen as promising, indicating that there are numerous alternatives to GaN worth exploring for high-frequency power and RF electronics. Among those identified were materials that are suitable for both high power and high switching frequency and for which the dopability has already been predicted: InBO3, In2Si2O7, In2Ge2O7, and ZnGeN2.  

Further dopability assessment should be made on other possible alternatives, followed by thin film growth and, depending on the device architecture, identification of suitable contacts and complementary materials for heterostructures. The realisation of devices based on these new semiconductors could enable faster, more compact EV chargers, unlock high-power wireless power transfer and extend the capabilities of RF systems for next-generation communications, radar and sensing technologies.  

So the hunt for alternatives to GaN is already happening in the US, which could mean that GaN’s superiority when it comes to military applications is not infinite. A lot will rest on these studies, but because they will take considerable time before anything with the required technical ability, cost competitiveness and production suitability is firmly established, GaN will remain the go-to technology. 

As for the headline question, does GaN have military superiority? The answer has to be no. The global electronics industry never sits still when it comes to pushing technical capabilities further forward.  

To support that point, here’s a bit of history. Back in 1970, the industry hailed the arrival of the C1103 device, an 8μm p-MOS DRAM with 1 kilobit capacity. Just as with that device, it is inevitable that GaN will be overtaken by a technically more capable successor.