Chemical vapor deposition apparatus and method of forming semiconductor epitaxial thin film using the same

1. A chemical vapor deposition apparatus comprising:

a reaction chamber including an inner tube having a predetermined volume of an inner space, and an outer tube tightly sealing the inner tube;

a wafer holder disposed within the inner tube and on which a plurality of wafers are stacked at predetermined intervals;

a gas supply unit including at least one gas line supplying an external reaction gas to the reaction chamber, and a plurality of spray nozzles communicating with the gas line to spray the reaction gas to the wafers, whereby semiconductor epitaxial thin films are grown on the surfaces of the wafers; and

a guide unit disposed between the spray nozzles and the wafers, the guide unit guiding the flow of the reaction gas so that the reaction gas sprayed from the spray nozzles flows to the top and bottom surfaces of the respective wafers,

wherein the semiconductor epitaxial thin film grown on the surface of the wafer includes a light emitting structure in which a first-conductivity-type semiconductor layer, an active layer, and a second-conductivity-type semiconductor layer are sequentially formed.

2. The chemical vapor deposition apparatus of claim 1 , wherein the gas supply unit extends vertically in a wafer stacking direction, and the plurality of spray nozzles are arranged corresponding to the stacking intervals of the wafers, such that the spray nozzles are arranged at vertical positions facing the sides of the stacked wafers.

3. The chemical vapor deposition apparatus of claim 1 , wherein the gas supply unit extends vertically in a wafer stacking direction, and the plurality of spray nozzles are arranged between the stacked wafers.

4. The chemical vapor deposition apparatus of claim wherein the gas supply unit further includes a cooling line provided around the gas line to allow a coolant to flow therethrough in order to cool the reaction gas.

5. The chemical vapor deposition apparatus of claim 4 , wherein the gas supply unit includes a first gas line supplying a first reaction gas and a second gas line supplying a second reaction gas, the first gas line and the second gas line being disposed within the cooling line.

6. The chemical vapor deposition apparatus of claim 1 , wherein one or more gas supply units are provided to supply the same reaction gas or separately supply different reaction gases.

7. The chemical vapor deposition apparatus of claim 1 , wherein the gas supply unit further includes an auxiliary line which communicates with the gas line and the cooling line and sprays the reaction gas, the auxiliary line being disposed horizontally around the periphery of the wafers to surround the wafers.

8. The chemical vapor deposition apparatus of claim 7 , wherein the auxiliary line has a ring shape having a diameter greater than that of the wafer, the auxiliary line includes:

an auxiliary gas line including a plurality of spray nozzles which communicate with the gas line and spray the reaction gas supplied from the gas line; and

an auxiliary cooling line provided around the auxiliary gas line to communicate with the cooling line and allow a coolant to flow therethrough in order to cool the reaction gas.

9. The chemical vapor deposition apparatus of claim 8 , wherein the auxiliary line includes a first auxiliary gas line supplying a first reaction gas, and a second auxiliary gas line supplying a second reaction line.

10. The chemical vapor deposition apparatus of claim 7 , wherein the auxiliary line is disposed between the stacked wafers or arranged corresponding to the stacking intervals of the wafers to face the sides of the wafers.

11. The chemical vapor deposition apparatus of claim 1 , wherein the guide unit is disposed between the spray nozzles and the wafers and has an upper inclined surface and a lower inclined surface which are inclined toward the spray nozzles and contacted together in order to reduce a cross-sectional area in a direction from the wafers toward the spray nozzles.

12. The chemical vapor deposition apparatus of claim 1 , wherein the guide unit is vertically arranged corresponding to the stacking intervals of the waters to face the sides of the stacked wafers.

13. The chemical vapor deposition apparatus of claim 1 , wherein the guide unit is vertically arranged corresponding to the stacking intervals of the wafers to face a space between the stacked wafers.

14. The chemical vapor deposition apparatus of claim 1 , wherein the guide unit extends from the wafer holder toward the spray nozzles and is arranged vertically in a wafer stacking direction.

15. The chemical vapor deposition apparatus of claim 1 , wherein the guide unit is arranged vertically in a wafer stacking direction by at least one pair of support pins and is detachably mounted on the wafer holder to face the spray nozzles.

16. The chemical vapor deposition apparatus of claim 1 , further comprising a rotation driving unit connected to the wafer holder to rotate the wafer holder.

17. The chemical vapor deposition apparatus of claim 1 , wherein the light emitting structure further includes a first electrode formed on the first-conductivity-type semiconductor layer, and a second electrode formed on the second-conductivity-type semiconductor layer.

18. The chemical vapor deposition apparatus of claim 17 , wherein the first electrode is formed on the first-conductivity-type semiconductor layer, a portion of which is exposed by mesa etching, and the second electrode is formed on a transparent electrode layer which is formed on the second-conductivity-type semiconductor layer.

19. The chemical vapor deposition apparatus of claim 4 , wherein the gas line is disposed inside the cooling line to allow a coolant flowing through the cooling line to cool the reaction gas flowing through the gas line.