The industry is moving toward larger substrate diameters and better material quality for faster adoption in high-volume applications.
The supply chain for emerging substrates is generally not well established dominated by start-ups and spin-offs from academic research institutes.
With the need to improve the performance and the cost limits, new materials, platforms, and designs are being continually investigated in the semiconductor industry.
“The power electronics market, driven by several applications such as EV/HEV , renewable energy, and power supplies, is still dominated by Silicon-based technologies. Nevertheless, the wide bandgap materials SiC and GaN (Lateral GaN HEMT on Si or Sapphire) have penetrated the power electronics market after a long development process and are expected to constitute more than 25% of the PE market by 2028,” says Yole’s Taha Ayari, “benefitting from this momentum, Yole expects bulk GaN for vertical GaN devices and engineered substrates (SmartSiC™ from Soitec, SiCkrest from SICOXS, and QST from Qromis) to grow in the coming five years.”
The photonics market, on the other hand, enjoys stable growth with GaSb-based devices such as IR lasers and imagers driven mainly by high-end and niche military applications.
Concerning the bulk GaN substrates in consumer, industrial, and automotive applications, the market is considered stable with a stronger push into industrial applications.
During the pandemic, UVC disinfection/purification systems started using bulk AlN substrates. This could drive the AlN substrates market to a CAGR2022-2028 of 22%, the highest among all the emerging photonics substrates.
For the power electronics industry, at least a 6-inch wafer size is needed for established foundries to be involved at high volumes. This pushes the substrate players to optimise the manufacturing techniques and to increase the wafer sizes.
For diamond, the mosaic diamond method from EDP that delivers up to 28 x 28 mm² and heterogeneous diamond growth on Si or sapphire substrates from Orbray or Audiatec up to around 6-inch diameter have been developed.
In addition, 6-inch bulk GaN substrates have been demonstrated using HVPE and other techniques, though more work is still needed to improve the material quality and meet application requirements.
Similarly, for Ga2O3, different melt growth techniques are being used, with EFG the most promising to obtain 6-inch wafers with acceptable material quality in volume production.
With engineered substrates, advanced splitting and bonding techniques are used to overcome challenges for larger single-crystal substrates and better material quality.
