The mass adoption of GaN on Si technology for LED applications remains uncertain. Opinions regarding the chance of success for LED-On-Si vary widely in the LED industry from unconditional enthusiasm to unjustified skepticism. Although significant improvements have been achieved, there are still some technology hurdles (such as performance, yields, CMOS compatibility, etc.).
The differential in substrate cost itself is not enough to justify the transition to GaN on Si technology. The main driver lies in the ability to manufacture in existing, depreciated CMOS fabs in 6” or 8”. For Yole Développement, if technology hurdles are cleared, GaN-on-Si LEDs will be adopted by some LED makers, but it will not become an industry standard.
Yole is more optimistic about the adoption of GaN on Si technology for power GaN devices. Contrary to LED industry, where GaN on Sapphire technology is the main stream and presents a challenging target, GaN on Si will dominate the GaN based power electronics applications. Although the GaN based devices remain more expensive than Si based devices, the overall cost of GaN device for some applications are expected to be lower three years from now according to some manufacturers.
In 2020, GaN could reach more than 7 percent of the overall power device market and GaN on Si will capture more than 1.5 percent of the overall power substrate volume, representing more than 50 percent of the overall GaN on Si wafer volume, subjecting to the hypothesis that the 600 V devices would take off in 2014-2015.
GaN targets a $15 billion served available device market. GaN can power 4 families of devices and related applications. These are blue and green laser diodes, LEDs, power electronics and RF (see image).
Regarding GaN-on-Si LED, there will be no more than 5 percent penetration by 2020. As for GaN-on-GaN, it will be less than 2 percent. Yole considers that the leading proponents of LED-On-Si will successful and eventually adopt Si for all their manufacturing. Those include Bridgelux/Toshiba, Lattice Power, TSMC and Samsung. It expects that Silicon will capture 4.4 percent of LED manufacturing by 2020.
GaN wafer could break through the $2000 per 4” wafer barrier by 2017 or 2018, enabling limited adoption in applications that require high lumen output other small surfaces.
There are more available solutions than ever in power devices, according to Alexandre Avron, market and technology analyst, Yole Développement. The landscape is moving, and its moving quite fast, from every region of the world.
There are many opportunities for power device manufacturers. This is the time for strong strategic planning and making the best choices. He was speaking at a seminar on the power semiconductor devices industry, in Lyon, France.
IGBTs and SJ MOSFETs
Silicon is not dead and will still live for a long time. Standard device design are slowly disappearing (planar IGBT, planar MOSFET). IGBT and SJ MOS are highly mature technologies. Rules of competition are evolving.
Historic players need to keep on innovating. New entrants have a different business model: there are more and more foundries, with fab-less and fab-light players. IGBT is still a key asset: master and secure IGBT supply is necessary for system makers. SJ MOSFETS will be used in more and more systems, taking market shares to planar MOSFET.
About SiC and GaN, there is still a big question mark: Where and when? With time, it is becoming clearer. SiC will target medium and high power. From our point of view, medium power (1200V base) is a mean to arrive to high power (+3.3kV). R&D has to go through this to reach higher voltage. The main issue is still on current ratings (having a high impact on cost).
GaN will target low and medium power, and will probably allow extraordinary power supplies designs (Tiny supplies, very high frequency systems). It is almost ready for 600V, but not yet at 1200V. It leaves room for SiC to develop and expand. Major players are involved on both fields — SiC and GaN. They need to be present on both domains, as there will be an overlap, but the split is unclear: we will probably experience a very fine segmentation, not only by voltage or current, but also by frequency, ruggedness, system size, temperature of operation or maybe culture or history.
SiC is now here. First full SiC PV inverters are available. First field tests for SiC in rail traction is ongoing. GaN is under qualification. According to the most advanced players, 600V GaN devices samples are tested by system makers.