With the need to improve the performance and the cost limits, new materials, platforms and designs are being continually investigated in the semiconductor industry. In the previous decade, some compound semiconductors, such as GaAs for RF and SiC for power electronics, have succeeded in competing with silicon and have entered the mass market.
So, which emerging semiconductor substrate will be the next game changer? In its new Emerging Semiconductor Substrates 2023 report, Yole Intelligence, part of Yole Group, investigates the technological status of emerging semiconductor substrates, including GaSb, InSb, bulk GaN, Ga2O3, bulk AlN and diamond, as well as engineered substrates and templates. Furthermore, the market research and strategy consulting company examines various potential applications such as power electronics, RF, and photonics, including laser diodes, LEDs, sensors and detectors.
According to Taha Ayari, Ph.D., technology and market analyst, compound semiconductor and emerging substrates at Yole Intelligence, part of Yole Group, "The PE 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 percent of the PE market by 2028. Benefiting from this momentum, Yole Intelligence 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. While GaSb is growing, what is the market status of InSb? Yole Intelligence’s analysts review this question in this emerging semiconductor substrates report.
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 CAGR 2022-2028 of 22 percent, the highest among all the emerging photonics substrates.
According to Ali Jaffal, Ph.D., technology & market analyst specializing in compound semiconductors and emerging substrates at Yole Intelligence, “Emerging substrate activities focus mainly on technological development for better material quality, higher yields and lower production costs. This push needs, of course, to be supported by market demand and adoption in volume applications which defines the correct specification of the different substrates. This comes together with increasing the substrate diameter which gives the impetus to emerging substrates industry to go towards mass production.”
For the power electronics industry, at least a 6-in. wafer size is needed for established foundries to be involved at high volumes. This pushes the substrate players to optimize 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-in. diameter have been developed. In addition, 6-in. 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. Regarding engineered substrates, advanced splitting and bonding techniques are used to overcome challenges for larger single-crystal substrates and better material quality.