Recently, China’s synthetic sapphire industry has achieved several key technical milestones. Records have been set for extra‑large crystal ingots, while synthetic sapphire is rapidly expanding into semiconductors, 2D materials and high‑end optics. Once mostly used for LED substrates and watch glass, synthetic sapphire has become a major growth driver for China’s advanced materials sector.

Synthetic sapphire is made of high‑purity alumina. With a Mohs hardness of 9, second only to diamond, it features high light transmittance, high‑temperature resistance, excellent insulation and corrosion resistance. It serves as a core substrate material for LED chips and is widely applied in smart wearable covers, laser windows and semiconductor components. For years, technical barriers existed for large‑size, high‑purity sapphire crystal growth. After years of upgrades, Chinese enterprises have realized full independent control over equipment and crystal materials.

In early August, Jing Sheng Machinery based in Shaoxing, Zhejiang, unveiled a world‑record‑breaking 1000‑kilogram ultra‑large synthetic sapphire crystal grown by the Kyropoulos method. On display alongside it were 450‑kilogram sapphire ingots and a 150‑kilogram synthetic ruby sample. The company entered the sapphire business in 2013. Its crystal weight has risen step‑by‑step from 300 kg to 450 kg, 750 kg and finally the ton‑level product.

Large ingots can yield far more large‑size wafers from a single crystal, lowering per‑unit costs. This is critical for mass production of 8‑inch and 12‑inch sapphire wafers for Micro‑LED, GaN radio‑frequency devices and high‑power optical windows.

Beyond oversized crystals, synthetic sapphire is making headway in cutting‑edge semiconductors. In July, ORD completed sample delivery of special‑crystal‑orientation sapphire substrates for 2D semiconductor research. Cutting‑angle precision reaches within 0.01°, satisfying strict surface‑structure requirements for 2D‑material epitaxy. This marks a key shift for domestic sapphire manufacturers from consumer‑electronics and LED processing toward high‑end semiconductor substrate suppliers.