Germany-based Azzurro Semiconductor AG has turned out sample 8-inch Ga-on-Si (gallium on silicon substrates) LED epitaxial wafers and plans to begin volume production as soon as the end of the second quarter of 2013, according to company Sales & Marketing vice president Erwin Ysewijn.
Azzurro has spent about one year in preparation for volume production, Ysewijn said. LED makers can either procure Azzurro-made finished GaN-on-Si LED epitaxial wafers for LED chips, or procure Si-substrate wafers with GaN films for LED epitaxial wafers, Ysewijn indicated.
LED chips made from GaN-on-Si epitaxial wafers have a 5% lower luminous efficiency than LED chips made from sapphire wafers, but the unit price of ERU0.20/(US$0.27) square cm for the former is lower than that of EUR0.30 for the latter, Ysewijn pointed out.
Because almost all LED chip makers use sapphire wafers, few of them are willing to change production equipment to adopt GaN-on-Si epitaxial wafers, Ysewijn noted. However, GaN-on-Si technology is a long-term development for large-size LED epitaxial wafers, Ysewijn emphasized.
Epistar, the largest Taiwan-based LED chip maker, is evaluating the feasibility of adopting GaN-on-Si technology, the company indicated.