Aluminum nitride has higher thermal conductivity. The inertia is extremely stable under a high-temperature environment. In the air, the substance's surface will become oxidation when the temperature higher than 700℃. At normal temperature, the substance's surface still has 5 to 10 nano oxidation membranes. When the temperature reaches 1370℃, the oxidation membrane still can protect the substance. However, when the temperature higher than 1370℃, the whole substance will frequently react to oxidation. Straight up to 980℃, the aluminum nitride would be still stable in hydrogen and carbon dioxide. Nowadays, aluminum nitride is widely used in the cooling substrate and semiconductor processes.