A relatively unknown material, Scandium-doped Aluminum Nitride, is partly responsible for the 5G and IoT (Internet of Things) revolution and will be at the heart of a wide array of futuristic sensors and communication for the “internet of things.” Let us take a deeper look into 5G, IoT, and the material that is the backbone to enabling advances in these technologies
5G is the new set of standards that have been set up by the Federal Communications Commission (or FCC) and is replacing the 4G network that’s in your phone. As 5G bands are rolled out, they will significantly change the way people interact with the digital world. For example, downloading a movie on your phone or tablet can currently take 5 to 10 minutes, but with 5G technology it could eventually only take six seconds. The same system will be managing your healthcare, managing your smart home, and operating the “factory of tomorrow.” In addition, the network will also be critical to the autonomous or self-driving cars we've been hearing about for years. All this advanced technology depends very heavily on a very stable and highly reliable wireless system. It's really going to change everything we touch in our world, the digital world, and the way we interact with it. This extreme digitization of “things” is starting to take shape now.
The Internet of Things is made up of billions of smart devices that all communicate with each other. Examples of devices range from wearables, like a smartwatch or fitness band, to your cellphone to household appliances to large machines that run production factories. It’s being referred to as the “Internet of Everything,” and we are starting to see this advanced shift in interconnected technology now.
An aluminum scandium sputtering target is a metallic disc of material somewhere between 12 and 16 inches in diameter and roughly a quarter of an inch thick. This small disk is a part of the technology that allows 5G and IoT to function 24 hours a day, 7 days a week. These targets are sputtered using a nitrogen-containing gas to deposit a thin film of scandium aluminum nitride on a silicon wafer. The scandium aluminum nitride is piezoelectric, and it is this key property that is exploited to produce the RF (radio frequency) filters at the heart of the current wireless proliferation.
The scandium aluminum sputter target material is manufactured by traditional metal casting technology. This material is highly uniform, very high purity and very highly engineered so that when sputtered the deposited film chemistry is consistent wafer to wafer. In addition, the microstructure of the target needs to be highly consistent to ensure that other film properties, such as in-plane stress, are consistent over the life of the target. Although the targets are nominally simple metallic materials, they are highly engineered to deposit very complex films.
The material that Materion manufactures is a deceptively simple binary alloy system consisting of Aluminum and Scandium. However, in practice some very challenging development was required to create the microstructure and chemistry in the target to provide the correct film properties. It took multiple engineers more than six years to perfect this material. Part of the challenge was that materials that are metallurgically sound are not necessarily going to deposit films with the requisite properties. The company overcame this challenge by partnering closely with customers and working together to create a material which is uniquely tailored to a manufacturer’s particular processes. Once a material was found that worked, further engineering was required for it to run consistently in customers’ tools, and to enable very high-volume manufacturing.
The development of these materials demonstrates how manufacturing teams can successfully respond to customer challenges. Typically, metallurgists, material scientists, and chemists work with the customers device experts and process engineers and develop a common language to be able to say, “…if we do this to our target, it does this to your device level.” Clearly communicating with their engineers, explaining what the targets do, how the manufacturing process affects the targets, and then determining what is required to make the materials to meet the customer’s specific process, is the magical part of being able to produce this material. Finding a key partner able to accomplish this with your production team is essential. This allows for rapid development of highly tailored product, which is essential to the success of your customers’ programs.
A manufacturer was approached a few years ago by a large wireless company, looking to make bulk acoustic wave filters out of compositions and tolerances that none of the industry had even considered. This manufacturer had a top-notch reputation and was willing to work on challenging materials that were at the cutting edge of the industry. Intensive work was put in to optimize materials for their processes and designs for development of a product that helped them win multiple design awards at end customers, where they are currently producing high volume product. When we say high volume, we mean they're making billions of devices. This is how the next two generations of wireless products are produced in harmony. Like everything in manufacturing, it’s a team effort.
BAW Application of Aluminum Scandium Material in 5G. Learn more about the evolution of 5G wireless communications through the development of AlSc material in BAW-based 5G RF filters.
