(Al, Ga, In)N-based compound semiconductor and method of fabricating the same
View Patent ↗Disclosed are a (Al, Ga, In)N-based compound semiconductor device and a method of fabricating the same. The (Al, Ga, In)N-based compound semiconductor device of the present invention comprises a substrate; a (Al, Ga, In)N-based compound semiconductor layer grown on the substrate; and an electrode formed of at least one material or an alloy thereof selected from the group consisting of Pt, Pd and Au on the (Al, Ga, In)N-based compound semiconductor layer. Further, the method of fabricating the (Al, Ga, In)N-based compound semiconductor device comprises the steps of growing a P layer including P type impurities in a growth chamber; discharging hydrogen and a hydrogen source gas in the growth chamber; lowering the temperature of the (Al, Ga, In)N-based compound semiconductor with the P layer formed thereon to such an extent that it can be withdrawn to the outside from the growth chamber; withdrawing the (Al, Ga, In)N-based compound semiconductor from the growth chamber; and forming an electrode of at least one material or an alloy thereof selected from the group consisting of Pt, Pd and Au on the p layer. According to the present invention, it is possible to sufficiently secure P type conductivity and obtain good ohmic contact characteristics without performing an annealing process. And, no further annealing is necessary when Pt, Pd, Au electrode are used.
1. A method of fabricating a (Al, Ga, In)N-based compound semiconductor device, comprising:
growing a (Al, Ga, In)N-based compound semiconductor layer (P layer) including P type impurities on a substrate in a growth chamber including hydrogen carrier gas along with source gases including ammonia gas;
discharging hydrogen, ammonia and gas including hydrogen from the growth chamber at a temperature higher than a temperature at which impurities in the P layer and hydrogen contained in the gases are bonded to each other after the growth of the P layer is completed;
after the discharging of the hydrogen, ammonia and gas including hydrogen, lowering the temperature of the substrate with the P layer formed thereon to such an extent that the substrate can be withdrawn to the outside from the growth chamber;
withdrawing the substrate with the P layer formed thereon from the growth chamber; and
forming an electrode on the P layer, the electrode comprising Pt, or a combination of Pt and at least one of Pd and Au, or an alloy of Pt and at least one of Pd and Au,
wherein the grown P layer is not subjected to an annealing process.
2. The method as claimed in claim 1 , wherein lowering the temperature is performed by means of water cooling or air cooling of the growth chamber.
3. The method as claimed in claim 1 , wherein lowering the temperature comprises:
maintaining the growth chamber under vacuum conditions; and
supplying a cooling gas into the growth chamber under vacuum conditions.
4. A method of fabricating a P layer of a (Al, Ga, In)N-based compound semiconductor, comprising:
growing the P layer by supplying a carrier gas including hydrogen along with source gases including ammonia gas into a growth chamber while maintaining temperature in the growth chamber at a temperature for growth of the P layer of the (Al, Ga, In)N-based compound semiconductor;
stopping the supply of the carrier gas and source gases after the growth of the P layer is completed;
discharging the gases existing in the growth chamber at a temperature higher than a temperature at which impurities in the P layer and hydrogen contained in the gases are bonded to each other;
lowering the temperature of the P layer of the (Al, Ga, In)N-based compound semiconductor;
withdrawing the substrate with the P layer formed thereon from the growth chamber; and
forming an electrode on the P layer, the electrode comprising Pt, or a combination of Pt and at least one of Pd and Au, or an alloy of Pt and at least one of Pd and Au,
wherein the grown P layer is not subjected to an annealing process.
5. The method as claimed in claim 4 , wherein the temperature of the P layer is lowered by means of air cooling or water cooling.
6. The method as claimed in claim 4 , wherein lowering the temperature of the P layer comprises:
maintaining the growth chamber under vacuum conditions; and
supplying a cooling gas into the growth chamber under vacuum conditions.
7. The method as claimed in claim 4 , wherein the temperature for the growth of the P layer is in a range of 600 to 1,300° C.
8. The method as claimed in claim 4 , wherein the temperature at which the gases existing in the growth chamber are discharged is in a range of 400 to 1,300° C.