Cracks Could Affect GaN-on-silicon LED Market
According to Lux Research, gallium nitride-on-sapphire remains the entrenched incumbent. The main challenger GaN-on-silicon will gain only a 10 percent market share
As LED lighting becomes an $80 billion industry, the market for the epitaxial wafers LEDs are made from will grow to $4 billion in 2020.
This is according to Lux Research's Energy Electronics Intelligence service report titled “Dimming the Hype: GaN-on-Si Fails to Outshine Sapphire by 2020."
Today, the vast majority of these epi-wafers are GaN-on-sapphire.
GaN-on-silicon is the leading emerging technology with a strong economic allure as silicon is just one-eighth the cost of a sapphire substrate.
But, according to Lux, technical challenges will limit it to only a 10 percent market share in 2020.
GaN-on-SiC, championed by Cree, will grow to 18 percent market share.
“Silicon is already widely used for electronics, and some LED die manufacturers are hoping to take advantage of silicon substrates," says Pallavi Madakasira, Lux Research Analyst and lead author of the report.
“But GaN-on-Si is more prone to cracking than GaN-on-sapphire, and mitigating this mismatch is expensive," she adds.
However, growing AlN (aluminium nitride) as a nucleation layer with a buffer on top of it can reduce the mismatch between GaN and silicon.
Lux Research analysts studied the market for GaN-on-sapphire, GaN-on-SiC, GaN-on-bulk GaN, and GaN-on-Silicon epi-wafers, evaluating each technology's economic prospects as the industry moves to larger wafer sizes.
They said the choice and cost of LEDs will determine adoption. Where GaN-on-sapphire is suited to all applications, GaN-on-bulk GaN will be relegated to niche commercial lighting and GaN-on-Silicon, with unproven performance, will be better suited to cost-sensitive residential applications.
Lux also said four inch wafers will rule, although six inch wafers will start to come into vogue later on. Four inch wafers will peak at 62 percent market share with $2.1 billion in 2017 sales.
Later, the LED industry will move towards 6" epi wafers, which will take a 35 percent share, equivalent to $1.4 billion, in 2020.
According to Lux, technology will advance sapphire substrates.
Sapphire substrate manufacturing technology has advanced significantly with specialists such as Rubicon and Monocrystal demonstrating substrates up to 12" in diameter.
New methods will further improve throughput and cut costs, keeping sapphire highly competitive for the rest of the decade.
For example, using its Remote Plasma Chemical Vapour Deposition (RPCVD) technology, Australian based firm BluGlass has grown p-GaN on a commercially 456nm blue multi quantum well structure.