Development of 300m GaN Fabrication Well Underway

­Some of the most impactful leaps in semiconductor technology come when the industry moves to a larger wafer size for manufacturing. The increase in productivity drops the cost of chips, making new technologies very much cheaper, which, in turn, boosts adoption as designers no longer have to trade-off performance and cost. That increased market share also gives an incentive to chip manufacturers to innovate further. Currently most GaN devices are made on 200mm wavers, while silicon ones are fabricated on 300mm wavers. 300mm wavers have a 50% greater surface area than 200mm ones, providing a correspondingly greater number of similarly sized dies. That larger output gives silicon a competitive advantage over GaN devices, all other things being equal. If GaN could be fabricated on 300mm wavers, then that advantage could mostly be nullified. However, it is not as easy as just transferring the designs to 300mm wavers. Fabricating GaN designs are much more complex than silicon ones. It is only fairly recently that the GaN manufacturing process has been transferred to a 200mm process, however work on the 300mm process is already well underway.

That new technological leap is led by vertical manufacturers, such as Infineon, but now other organizations are starting to ramp up reasearch, which will allow fabless companies to compete. For example, the Belgian research and innovation hub, IMEC, has launched a 300mm GaN program which will develop advanced power devices and reduce manufacturing costs. The launch announcement for the institute’s innovation program track for low- and high-voltage power electronics applications included partners AIXTRON, GlobalFoundries, KLA Corporation, Synopsys. The initiative is part of IMEC’s industrial affiliation program (IIAP) on GaN power electronics, and the organizations will together develop 300mm GaN epi growth, and low and high voltage GaN high electron mobility transistor (HEMT) process flows.

The use of 300mm substrates will not only reduce GaN device manufacturing costs, but it will also allow the development of more advanced power electronics devices, such as efficient low-voltage point-of-load converters for CPUs and GPUs.

Stefaan Decoutere, fellow and program director of the GaN power electronics program at imec explained, “The benefits of transitioning to 300mm wafers go beyond upscaling production and reducing manufacturing costs. Our CMOS-compatible GaN technology now has access to 300mm state-of-the-art equipment that will allow us to develop more advanced GaN-based power devices.

Examples are aggressively scaled low-voltage p-GaN gate HEMTs for use in point-of-load converters, supporting energy-efficient power distribution for CPUs and GPUs.”

He continued, “The success of the 300mm GaN development also hinges on the ability to establish a robust ecosystem and jointly drive innovation from 300mm GaN growth and process integration to packaging solutions. Developing advanced GaN power electronics requires close coupling between design, epitaxy, process integration, and applications.”

The launch of the 300mm GaN program follows successful 300mm wafer handling tests and mask set development. Imec expects to have full 300mm capabilities installed in its 300mm cleanroom by the end of 2025.