KR20090058769A - Chemical vapor deposition apparatus - Google Patents

Abstract

A chemical vapor deposition device is provided to perform the chemical evaporation of a wafer uniformly by maintaining the stable laminar flow. A chemical vapor deposition device comprises: a chamber having an internal space of the constant size; a gas blowing nozzle(120) supplying the reaction gas to the inside of the chamber; a susceptor(130) laying one or more wafers(2), arranged within the chamber inside to be rotatable; a heater(140) arranged in a lower surface of the susceptor to serve the heat; and a flow rate control part(150) downwardly inclining toward the gas ventilation direction of the chamber in the hot zones to uniformly maintain the volume of a gas flow path at the hot zone where the heat convection of the wafer generates.

Description

Chemical Vapor Deposition Apparatus {Chemical Vapor Deposition Apparatus}

The present invention relates to a device for forming a high temperature chemical vapor deposition on a substrate, and more particularly, having a flow rate control part on the inner surface of the chamber to change the height of the chamber to maintain a uniform flow rate of the reaction gas in the chamber. The present invention relates to a chemical vapor deposition apparatus in which chemical vapor deposition occurs uniformly across a wafer.

As high-efficiency LEDs are increasingly used in various industries, chemical vapor deposition (CVD) equipment that can be produced in large quantities without degrading quality or performance is required. Accordingly, by increasing the size of the CVD reactor, a reactor having a new structure capable of growing dozens of existing 2-inch wafers at the same time, or growing wafers of large diameter (4, 6, 8, 12 inch sizes) ( Chamber).

In the chemical vapor deposition method, a wafer is placed on a susceptor in a chamber and a reaction gas is supplied to form a thin film on the surface of the wafer. The part should be sprayed evenly throughout.

FIG. 1 illustrates a general radial type chemical vapor deposition apparatus, and the apparatus 30 is rotatably disposed in the chamber 31 and a chamber 31 having a predetermined internal space. From a susceptor 32 on which a plurality of substrates 2 are placed, a heating means 33 disposed below the susceptor 32 to provide heat, and an upper surface of the chamber 31. It consists of a reaction gas injection nozzle 34 extending to the upper portion of the acceptor 32.

The device 30 has a source gas and a carrier gas, which are reactant gases, through the reaction gas injection nozzle 34 extending to the vicinity of the upper surface of the susceptor 32. By flowing into the central region of the upper surface of the surface, the incoming reaction gas forms a thin nitride film on the surface of the substrate 2 due to chemical vapor deposition on the substrate 2 at a high temperature, and the residual gas or dispersion is discharged into the chamber 31. It will be discharged to the bottom of the wall.

Here, trimethylgallium (TMGa), triethylgallium (TEGa), trimethylindium (TMIn), trimethylaluminum (TMAl), and the like are used as the Group 3 gas as the source gas, and ammonia and the like are used as the carrier gas.

On the other hand, FIG. 2 is an enlarged view of part A of FIG. 1, and in the conventional general CVD reactor, it is common to have a structure having a uniform height of a chamber.

However, the gas formed by the reaction gas passing between the inner surface of the chamber 31 and the susceptor 32 moves away from the injection nozzle 34 located in the center of the chamber 31 toward the gas exhaust side. The flow path (F) is diffused in the fan-like direction to increase the volume, the flow rate of the reaction gas moving along the gas flow path (F) is reduced, so that it is difficult to maintain a uniform and stable laminar flow (flow flow) (laminar flow) have.

In addition, since the susceptor 32 is differentially heated by the heating means 33, the temperature distribution is low at the periphery of the reaction gas injection nozzle 34, and the wafer 2 near the wafer 2 is deposited by the lower heating means 33. Maintains a relatively high temperature distribution.

Thus, it is more difficult to maintain a uniform and stable laminar flow near the wafer 2 due to the strong heat convection caused by the high temperature near the wafer 2.

Due to this phenomenon, as the size of the chamber increases, it becomes more difficult to secure uniformity of gas flow, which makes it difficult to form a uniform thin film on the wafer surface.

Accordingly, the present invention has been made to solve the above-described problems of the prior art, the chamber of the low temperature region in the center of the gas flow path to maintain a constant height, in the vicinity of the wafer in the high temperature region of the gas flow path so that the height is gradually lowered It is an object of the present invention to provide a chemical vapor deposition apparatus capable of maintaining a uniform flow rate of a reaction gas by providing a flow rate control unit on the inner surface to enable uniform chemical vapor deposition.

As a technical configuration for achieving the above object, the chemical vapor deposition apparatus of the present invention comprises a chamber having an internal space of a predetermined size; A gas injection nozzle for supplying a reaction gas into the chamber; A susceptor rotatably disposed in the chamber and on which at least one wafer is placed; A heater disposed on a lower surface of the susceptor to provide heat; And a gas inclined downward toward the gas exhaust side of the chamber in the high temperature region such that the volume of the gas flow path in the high temperature region where the tropical flow of the wafer is generated is maintained on the inner surface of the chamber facing the susceptor. It includes a flow rate control unit.

Preferably, the gas injection nozzle is composed of at least one gas inlet provided to form a radial gas flow toward the outer peripheral side from the center of the susceptor, is provided on the upper inner surface of the chamber corresponding to the center of the susceptor .

Preferably, the flow rate control part is provided in an annular shape from the boundary between the low temperature region around the reaction gas injection nozzle and the high temperature region where tropical flow of the wafer occurs.

More preferably, the boundary portion has a temperature distribution between a low temperature region having a temperature distribution of 200 ° C to 300 ° C and a high temperature region having a temperature distribution of 800 ° C to 1000 ° C.

Preferably, the flow rate control unit is provided to be detachable from the inner surface of the chamber.

More preferably, the flow rate control unit is composed of at least two partition members.

More preferably, the flow rate control unit is made of a material having a lower thermal conductivity than the chamber.

Preferably, the flow rate controller is formed such that the upper surface of the chamber corresponding to the high temperature region of the wafer is inclined downward at a predetermined angle along the gas exhaust side direction.

More preferably, the flow rate control unit has a straight or curved surface in contact with the reaction gas flowing from the reaction gas injection nozzle.

Preferably, the flow rate control unit does not exceed the inclination height (h) at the outer peripheral surface of the chamber 1% of the height (H) between the chamber and the susceptor.

Preferably, the chamber is provided with an additional cooling means for cooling the flow rate control unit on an outer surface corresponding to the flow rate control unit.

According to the present invention, the chemical vapor deposition is uniformly distributed throughout the wafer by maintaining a stable laminar flow, excluding the phenomenon that the flow rate of the reaction gas decreases as the volume of the gas flow passage increases away from the center of the chamber toward the gas exhaust side. To occur, it is possible to reduce the amount of reaction gas used.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic view showing an embodiment of a chemical vapor deposition apparatus according to the present invention, Figure 4 is an enlarged view of the portion B of Figure 3 is a schematic diagram showing the flow rate of the volume and the gas flow rate of the reaction gas and the reaction gas equipped with a flow rate control unit 5 is an enlarged perspective view illustrating the flow rate controller of FIG. 3. 6 is a schematic view showing another embodiment of the chemical vapor deposition apparatus according to the present invention, and FIG. 7 is an enlarged perspective view showing the flow rate control unit of FIG. 6.

The chemical vapor deposition apparatus 100 according to the present invention includes a chamber, a reaction gas injection nozzle, a susceptor, a heater, and a flow rate controller, as shown in FIGS. 3 and 6.

The chamber 110 according to an embodiment of the present invention is a vertical cylindrical structure having an internal space of a predetermined size, as shown in Figure 3 is made of a metal material excellent in wear resistance and corrosion resistance.

On the other hand, the reaction gas injection nozzle 120 for introducing a reaction gas from the outside into the chamber 110 in the upper side central portion of the chamber 110 having a diameter of a predetermined size is provided.

The reaction gas injection nozzle 120 is composed of at least one gas inlet 121 is provided to form a radial gas flow toward the outer peripheral side from the center of the susceptor 130, the center of the susceptor 130 and The upper inner surface of the corresponding chamber 110 is provided.

Therefore, the source gas and the carrier gas supplied from the outside are introduced into the chamber 110 through the reaction gas injection nozzle 120, and are injected to form a radial gas flow through the gas inlet 121. .

The susceptor 130 is rotatably disposed at a position facing the reaction gas injection nozzle 120 by a predetermined distance from the inner surface of the chamber 110. In this case, the rotation center axis of the susceptor 130 is disposed on the same line as the center axis of the reaction gas injection nozzle 120, and the rotation center axis of the susceptor 130 and the motor (not shown). Connect to rotate in a predetermined direction in the chamber 110 by the motor.

In addition, a plurality of wafers 2 are placed in the pocket 131 along the outer circumferential surface of the upper surface of the susceptor 130 at positions spaced apart by a predetermined distance from the rotational center axis, and the wafer 2 is heated. The heater 140 is provided on the bottom surface of the susceptor 130 to correspond to the position of the pocket 131.

On the other hand, Figure 4 is a perspective view showing an enlarged portion B of Figure 3, the gas flow path formed between the inner surface of the chamber 110 and the susceptor 130 by the susceptor 130 disposed as described above ( F) is shown.

As shown, the gas flow path (F) is adjusted by the distance (h1) between the susceptor 130 and the inner surface of the chamber 110, and away from the reaction gas injection nozzle 120 As it increases, the volume increases.

Therefore, the reaction gas introduced at a constant speed through the reaction gas injection nozzle 120 flows toward the gas exhaust side along the gas flow path F so that the velocity of the gas flow F expands gradually as the volume of the gas flow path F expands. do.

The heater 140 is provided on the lower surface of the susceptor 130 corresponding to the position where the wafer 2 is seated, as shown in FIG. 3, and the susceptor 130 so that a chemical vapor deposition reaction occurs on the wafer. Supply heat to the side.

At this time, as the susceptor 130 is differentially heated by the heater 140, an uneven temperature distribution is generated on the upper surface of the susceptor 130, whereby the portion where the wafer 2 is disposed is hot. The region H is formed, and the central axis portion of the susceptor 130 without the heater 140 forms a low temperature region L having a relatively low temperature (see FIG. 4).

The low temperature region (L) and the high temperature region (H) generated by the temperature distribution difference affect the flow of the reaction gas, and the strong heat convection (C) phenomenon occurring in the high temperature region (H) is stable. It does not allow to maintain laminar flow.

The flow rate control unit 150 shown in FIGS. 3 and 4 is to prevent a decrease in flow rate due to the volume increase and to maintain a stable laminar flow, and the chamber 110 facing the susceptor 130. The gas exhaust side of the chamber 110 in the high temperature region H such that the volume of the gas flow path F in the high temperature region H where the tropical flow of the wafer 2 is generated is maintained uniformly on the inner surface of the wafer 2. It is provided inclined downward in the direction.

The flow rate control unit 150 according to an embodiment of the present invention is provided to be detachable from the inner surface of the upper side of the chamber 110 through a screwing or fitting method, and at least two or more dividing members 151. ).

Therefore, in case of a problem caused by thermal deformation or self defect due to the internal temperature of the chamber 110 that maintains a high temperature state, there is an advantage in that maintenance is easy by allowing only the corresponding member to be replaced.

In order to prevent the occurrence of thermal deformation in the chamber 110 at a high temperature, the flow rate controller 150 may be made of a material having a lower thermal conductivity than the chamber 110, that is, a material such as quartz. Do.

6 and 7 illustrate the chamber 110 and the flow rate controller 150 according to another embodiment of the present invention, the upper surface of the chamber 110 through a method such as pressing or casting. From the high temperature region (H) of the wafer (2) to the outer peripheral surface of the chamber 110 to be inclined downward at a predetermined angle along the gas exhaust side direction.

As described above, the flow rate controller 150 is disposed between the low temperature region L around the reaction gas injection nozzle 120 and the high temperature region H where tropical flow of the wafer 2 occurs, as shown in FIGS. 4 and 5. From the boundary portion (M) of the outer peripheral surface of the chamber 110 is provided in a ring shape.

At this time, the boundary portion M has a temperature distribution between the low temperature region L having a temperature distribution of 200 ° C to 300 ° C and the high temperature region H having a temperature distribution of 800 ° C to 1000 ° C.

Accordingly, the gas flow path F maintains a constant height h1 in the low temperature region L around the reaction gas injection nozzle 120 and gradually increases in the high temperature region H where the wafer 2 is disposed. By lowering the structure), the flow rate of the reaction gas flowing along the gas flow path (F) toward the exhaust side can be maintained uniformly.

On the other hand, the flow rate controller 150 is preferably such that the surface in contact with the reaction gas flowing from the reaction gas injection nozzle 120 has a straight shape, to change to a curved shape for a more gentle gradient. It is also possible.

In addition, the flow rate controller 150 has an inclination height d at the outer circumferential surface of the chamber 110 exceeding 1% of the height h1 between the chamber and the susceptor corresponding to the height of the gas flow path F. FIG. Do not do it.

As described above, the gas flow path F extends radially toward the gas exhaust side by having a structure in which the height of the gas flow path F gradually decreases in the vicinity of the wafer in the high temperature region H through the flow rate control unit 150. It is possible to form a stable laminar flow by maintaining a uniform flow rate of the reaction gas according to the volume change of.

On the other hand, the outer surface of the chamber 110 is provided with a cooling means (water pipe) 160 in a position corresponding to the flow rate controller 150, the flow rate controller 150 heated by the internal temperature of the chamber 110 ) To cool.

This minimizes parasitic deposition occurring on the outer surface of the flow rate controller 150 in contact with the reaction gas so that the deposition reaction can occur uniformly throughout the wafer 2.

While the invention has been shown and described with respect to particular embodiments, it will be understood that various changes and modifications can be made in the art without departing from the spirit or scope of the invention as set forth in the claims below. It will be appreciated that those skilled in the art can easily know.

1 is a schematic view showing a typical radial type chemical vapor deposition apparatus.

FIG. 2 is an enlarged view of a portion A of FIG. 1 and illustrating a change in volume of a gas flow path and a flow rate of a reaction gas.

3 is a schematic view showing one embodiment of a chemical vapor deposition apparatus according to the present invention.

FIG. 4 is an enlarged view of a portion B of FIG. 3 and is a schematic diagram illustrating a change in volume of a gas flow path having a flow rate control unit and a flow rate of a reaction gas.

5 is an enlarged perspective view illustrating the flow rate controller of FIG. 3.

6 is a schematic view showing another embodiment of a chemical vapor deposition apparatus according to the present invention.

FIG. 7 is an enlarged perspective view illustrating the flow rate controller of FIG. 6.

<Description of the symbols for the main parts of the drawings>

100: chemical vapor deposition apparatus 110: chamber

120: gas injection nozzle 121: gas inlet

130: susceptor 131: pocket

140: heater 150: flow rate control unit

160 cooling means C: tropical flow

H: high temperature zone L: low temperature zone

M: boundary F: gas flow path

Claims (11)

A chamber having an internal space of a predetermined size; A gas injection nozzle for supplying a reaction gas into the chamber; A susceptor rotatably disposed in the chamber and on which at least one wafer is placed; A heater disposed on a lower surface of the susceptor to provide heat; And The flow velocity is provided to be inclined downward toward the gas exhaust side of the chamber in the high temperature region to maintain a uniform volume of the gas flow path in the high temperature region where the tropical flow of the wafer is generated on the inner surface of the chamber facing the susceptor Chemical vapor deposition apparatus comprising a control unit. The method of claim 1, The gas injection nozzle is composed of at least one gas inlet provided to form a radial gas flow toward the outer peripheral side from the center of the susceptor, characterized in that provided on the upper inner surface of the chamber corresponding to the center of the susceptor Chemical vapor deposition apparatus. The method of claim 1, And the flow rate controller is provided in an annular form from an interface between a low temperature region around the reaction gas injection nozzle and a high temperature region where tropical flow of the wafer occurs to an outer circumferential surface of the chamber. The method of claim 3, And the boundary portion has a temperature distribution between a low temperature region having a temperature distribution of 200 ° C to 300 ° C and a high temperature region having a temperature distribution of 800 ° C to 1000 ° C. The method of claim 1, The flow rate control unit is a chemical vapor deposition apparatus, characterized in that provided on the inner surface of the chamber detachable. The method of claim 5, The flow rate control unit is a chemical vapor deposition apparatus, characterized in that composed of at least two or more partition members. The method of claim 5, The flow rate control unit is a chemical vapor deposition apparatus, characterized in that made of a material having a lower thermal conductivity than the chamber. The method of claim 1, The flow rate controller is formed so that the upper surface of the chamber corresponding to the high temperature region of the wafer is inclined downward at a predetermined angle along the gas exhaust side direction. The method according to claim 5 or 8, The flow rate control unit is a chemical vapor deposition apparatus, characterized in that the surface in contact with the reaction gas flowing from the reaction gas injection nozzle has a straight or curved shape. The method of claim 1, The flow rate control unit is a chemical vapor deposition apparatus, characterized in that the inclination height (h) at the outer peripheral surface of the chamber does not exceed 1% of the height (H) between the chamber and the susceptor. The method of claim 1, The chamber is characterized in that the chemical vapor deposition apparatus further comprises a cooling means for cooling the flow rate control unit on the outer surface corresponding to the flow rate control unit.

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