Method for removing oxygen from aluminum nitride by carbon
Disclosed is a method for removing oxygen from aluminum nitride by carbon. At first, an oven is provided. An aluminum nitride substrate is located in the oven. Nitrogen is introduced into the oven to form an atmosphere of nitrogen. The temperature is increased to the transformation point of the aluminum nitride substrate in the oven. Then, the heating is stopped and quenching is conducted in the oven. Carbon is introduced into the oven in the quenching. Thus, oxygen included in the aluminum nitride substrate reacts with the carbon to produce carbon monoxide or carbon dioxide. The carbon monoxide or carbon is released from the oven as well as the nitrogen. Thus, the aluminum nitride substrate is purified.
1. A method for removing oxygen from aluminum nitride by carbon including the steps of:
providing an oven;
providing an aluminum nitride substrate in the oven,
introducing only nitrogen into the oven to form an atmosphere of nitrogen and increasing the temperature to the transformation point of the aluminum nitride substrate in the oven; and
stopping the heating and starting quenching in the oven, introducing carbon and nitrogen into the oven only during the quenching so that oxygen included in the aluminum nitride substrate reacts with the carbon to produce carbon monoxide or carbon dioxide, and releasing the carbon monoxide or carbon dioxide from the oven as well as the nitrogen, thus purifying the aluminum nitride substrate.
2. The method for removing oxygen from aluminum nitride by carbon according to claim 1 , further including the steps of providing a nitrogen supply unit connected to the oven and providing a carbon supply unit connected to the oven, wherein the oven includes an exhaust pipe formed thereon and at least one heating unit provided therein.
3. The method for removing oxygen from aluminum nitride by carbon according to claim 2 , wherein the nitrogen supply unit is connected to the carbon supply unit before they are connected to the oven.
4. The method of claim 3 , wherein the carbon is induced to flow into the oven via flow of the nitrogen from the nitrogen supply unit into the carbon supply unit.
5. The method for removing oxygen from aluminum nitride by carbon according to claim 2 , further including the step of providing valves among the oven, the nitrogen supply unit and the carbon supply unit.
6. The method for removing oxygen from aluminum nitride by carbon according to claim 1 , wherein the nitrogen supply unit provides nitrogen with concentration 2N to 6N.
7. The method for removing oxygen from aluminum nitride by carbon according to claim 1 , wherein the transformation point of the aluminum nitride substrate is higher than 1500° C.
8. The method for removing oxygen from aluminum nitride by carbon according to claim 1 , wherein the supply of the carbon and nitrogen starts when the temperature drops below 1500° C.