Method and device for decreasing generation of surface oxide of aluminum nitride
The present disclosure relates to a method and device for decreasing generation of surface oxide of aluminum nitride. In a physical vapor deposition process, the aluminum nitride is deposited on a substrate in a deposition chamber to form an aluminum nitride coated substrate. A cooling chamber and a cooling load lock module respectively perform a first stage cooling and a second stage cooling on the aluminum nitride coated substrate in vacuum environments, so as to prevent the aluminum nitride coated substrate with the high temperature from being exposed in an atmosphere environment to generate the surface oxide. The method and device for decreasing the generation of the surface oxide of the aluminum nitride can further eliminate crystal defects caused by that gallium nitride is deposited on the surface oxide of the aluminum nitride in the next process.
1. A method for decreasing generation of surface oxide of aluminum nitride of LED substrate, used in a physical vapor deposition (PVD) process, comprising:
step A, transmitting a substrate to a deposition chamber with a first vacuum environment, and depositing the aluminum nitride on the substrate to form an aluminum nitride coated substrate, wherein the substrate is a sapphire substrate;
step B, transmitting the aluminum nitride coated substrate to a first cooling chamber with a second vacuum environment, and performing a first stage cooling on the aluminum nitride coated substrate; and
step C, transmitting the aluminum nitride coated substrate that has performed the first stage cooling to a second cooling chamber with a third vacuum environment, and performing a second stage cooling on the aluminum nitride coated substrate for decreasing generation of surface oxide of the aluminum nitride coated substrate;
wherein a pressure of the second vacuum environment is less than a pressure of the third vacuum environment.
2. The method for decreasing the generation of the surface oxide of the aluminum nitride of LED substrate according to claim 1 , wherein in step B, the first stage cooling comprises at least one of a contact cooling, a quiescence cooling and a gas cooling.
3. The method for decreasing the generation of the surface oxide of the aluminum nitride of LED substrate according to claim 2 , wherein when the first stage cooling comprises the gas cooling, gas for cooling is inert gas.
4. The method for decreasing the generation of the surface oxide of the aluminum nitride of LED substrate according to claim 1 , wherein in step B, the first cooling chamber for performing the first stage cooling on the aluminum nitride coated substrate has a cooling temperature of 150-250° C.
5. The method for decreasing the generation of the surface oxide of the aluminum nitride of LED substrate according to claim 1 , wherein in step C, the second cooling chamber for performing the second stage cooling on the aluminum nitride coated substrate has a cooling temperature being less than 100° C.