In either a cautious or a more aggressive scenario, LED applications will certainly be the key drivers for the bulk GaN market, according to Yole Développement.
There is no doubt that LED technology will take market share over the traditional lamp and tube business. The recent announcements from LED makers (> 150 lm/W now in production) are proving that the performance roadmap is in line with expectations: LED does as well and even better than traditional bulbs and tubes.
Native bulk GaN emerges as an alternative to sapphire or silicon, allowing further improvement of LED performance. Despite potential performance benefits for UHB-LEDs, massive adoption of GaN wafers remains hypothetical. Taking into account the historical price reductions of bulk GaN substrates, a base scenario outlines where the GaN on GaN LEDs will be limited only to niche markets.
“If the GaN industry succeeds in replying to the cost pressure from LED makers and the price of four inch GaN wafers falls below the breakeven price, a more significant adoption could be forecast. We see an about three times difference in terms of market volume for LED manufacturing between the two scenarios,” explains Dr Hong Lin, Market & Technology Analyst, Compound Semiconductors, at Yole Développement.
The demand of GaN substrates for LD applications will probably decrease below 20k TIE/yr threshold in the coming years.
Blu-ray applications now represent the largest market for blue LD applications. This market will increase in the short term with the arrival of the new generation game stations. However, Yole Développement believes that this growth will not persist, as more and more people will play games and watch movies online instead.
Despite the recent rapid development of blue and green laser diodes, Yole Développement sees two scenarios for the adoption of GaN based laser diodes for the emerging projector market. The price of LDs is the essential factor to consider.
Combining all applications, the demand for two inch GaN substrates will be more than two times higher in the aggressive scenario than in the base scenario. In the best case, the demand would keep relatively stable until 2020.
In R&D, non-polar and semi polar substrates have been proposed for LD manufacturing. In principle, the semi polar approach seems to be the most promising in terms of device performance. In practice, c-plane based devices still have better performance.
More than 85% commercial GaN wafers are produced by HVPE, dominated by Japanese companies.
Today, essentially all commercial GaN wafers are produced by HVPE, but the details of the growth process and separation techniques vary from company to company – for example, ammonothermal growth at Mitsubishi Chemical, and the new acidic ammonothermeral method at Soraa. Na-flux LPE growth seems promising, but Yole Développement’s analysts have not yet seen many GaN devices based on those substrates. It will take some time to convince the device producers.
Non-polar and semi polar substrates have attracted significant attention. However, the substrate size is still very small and unsuitable for mass production.
As of today, the GaN substrates market is currently heavily concentrated with 87 percent held by Japanese companies. Non-Japanese players are currently in small volume production or in R&D stage, too early to challenge the market leaders. Without exception, Japan will continue to dominate the Bulk/FS GaN market for the coming years.
GaN substrates worldwide players (Yole Développement, November 2013)
Bulk GaN substrates for power electronics applications, a very challenging mission.
The GaN power device industry probably generated less than $2.5M in revenues in 2012. However, overall GaN activity has generated extra revenues as R&D contracts, qualification tests, and sampling for qualified customers was extremely buoyant. 16 out of 20 established power electronics companies are involved or will be involved in the GaN power industry.
Among the numerous substrates proposed for GaN power devices, bulk GaN solution is definitely beneficial to the device performance. However, Yole Développement remains quite pessimistic that bulk GaN could widely penetrate the power electronics segment unless 4” bulk GaN wafers can be in the $1,500 range by 2020.
The main reason is that, GaN power devices are positioned as a cost-effective solution, between incumbent Silicon and the ramping-up SiC technologies. If the $1,500 cost cannot be reached, then Yole Développement assumes no bulk GaN substrate will penetrate this market.