Sapphire is used for LEDs much like the computer industry uses silicon as a foundation for computer chips. Roughly 80% of the LED market uses sapphire for a foundation. Bridgelux has made some noise about building a larger diameter wafer out of silicon. Bridgelux contends that leveraging silicon would bring down costs by using existing automated semiconductor lines. However, the company admits that a number of the processes used to produce LEDs would have to be modified because some materials used are incompatible with silicon substrate manufacturing.
Bridgelux maintains that have to work 12 to 24 months to catch up with the sapphire companies. Rubicon Technology is already in volume production of 6 inch and 8 inch sapphire wafers for LED manufacturing. Others like Monocrystal and STC have been working to produce larger diameter sapphire wafers as well.
In an interview with Efficien’Si Magazine, Rubicon Technology CEO Raja Parvez says that LED manufacturers “want 8-inch production because it is more cost effective and re-utilises the current infrastructure available to them.” He says that a company like Rubicon can help companies move to larger diameter “through specification alignment and participation in customer design-of-experiments for process optimization. Many of our engineers are from the optoelectronics and semiconductor industries. Since we have this experience, and work with many LED chip companies, we can reduce the cycle time at the R&D level and reduce the trial period so they can move to production faster.”