Rubicon Technology claims it has successfully grown the world’s largest Al2O3 crystal, a boule that weighs in at 200 kg (441 lb). The company says it plans to use the material to form “high quality large-size optical windows and next-generation wafer products with dimensions over 12 in.”

This is quite a leap for Rubicon. Normally, it makes production volume sapphire boules in the 85 kg rage that yield 8 in. wafers and 10 in. optical windows.

The firm uses a proprietary crystal growth technology and believes it will be able to ramp up production volumes at this new, larger scale. “This growth capability now opens the door for Rubicon to provide customers with even larger size, very high-quality, sapphire products. The ‘super boule’ growth process will soon be operationalized into production volumes which will enable new applications for sapphire windows and wafers,” said Raja Parvez, CEO of Rubicon Technology.

Sapphire has use in LEDs, small optical and semiconductor devices, but large pieces of the material are wanted for transparent armor, pressure vessel windows and many other defense and underwater applications.

There is more than one way to form large-scale sapphire products. Saint-Gobain Crystals, for example, has a technique for creating sapphire “ribbons” using a pulling, controlled crystal orientation technique. With this approach, the company says it can make sheets that range in sizes up to 9 in. wide by 26 in. long, and 12 in. wide by 20 in. long that often are incorporated into defense applications.