JP3611943B2 - Substrate processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate processing method for carrying out a predetermined process on a substrate after the substrate is carried into a processing chamber via a load lock chamber.
[0002]
[Prior art]
Generally, in a thin film forming apparatus that forms a thin film on a wafer of a semiconductor device, when a wafer is loaded into a reaction chamber, it is loaded via a load lock chamber.
[0003]
Conventionally, the following two methods have been used as a method for carrying a wafer into a reaction chamber via a load lock chamber.
[0004]
In the first method, the reaction chamber is set in a vacuum state in advance, the wafer is loaded into the load lock chamber, the load lock chamber is set in a vacuum state, and the vacuum processing is completed. This is a method of carrying a wafer into a reaction chamber. In the second method, the atmosphere in the reaction chamber is set to N ₂ gas in advance, and when the wafer is loaded into the load lock chamber, the atmosphere in the load lock chamber is replaced with N ₂ gas. In this method, the wafer is loaded into the reaction chamber when the process is completed.
[0005]
FIG. 5 is a sequence diagram showing the first method, and FIG. 6 is a sequence diagram showing the second method. FIGS. 5 and 6 show only the sequence of the part where the wafer is carried into the reaction chamber from the load lock chamber.
[0006]
5 and 6, 401 indicates a reaction vessel, 402 indicates a load lock vessel, 403 indicates a gate valve, 404 indicates a boat, 405 and 407 indicate air valves, and 406 indicates a vacuum pump. , 500 indicates a wafer.
[0007]
In the first method, first, as shown in FIG. 5A, the air valve 405 is opened and the vacuum pump 406 is set to an on state. As a result, the load lock chamber B2 (the space formed by the load lock container 402) is evacuated. Next, as shown in FIG. 5B, the gate valve 403 is opened. Next, FIG.
As shown in (c), the wafers 500 accommodated in the boat 404 are transferred into the reaction chamber B1.
It is carried into (reaction space formed by the reaction vessel 401).
[0008]
In the second method, first, as shown in FIG. 6A, the load lock chamber B1 is evacuated. Next, as shown in FIG. 6B, the air valve 407 is opened. Thereby, N ₂ gas is supplied to the load lock chamber B2. Next, as shown in FIG. 6C, after the gate valve 403 is opened, as shown in FIG. 6D, the wafer 500 accommodated in the board 404 is carried into the reaction chamber B1.
[0009]
[Problems to be solved by the invention]
However, in either of the two methods described above, when the wafer 500 is transferred from the load lock chamber B2 to the high temperature reaction chamber B1, moisture or oxygen remaining in the load lock chamber B2 or the load lock chamber B2 is used. There is a problem in that the outgas from the wall surface of the metal is entrained in the reaction chamber B1 and a natural oxide film may be formed on the wafer 500.
[0010]
Accordingly, the present invention provides a natural oxide film on a substrate by transferring a residual atmosphere (residual moisture, residual oxygen, outgas, etc.) of the load lock chamber into the processing chamber when the substrate is transferred from the load lock chamber to the processing chamber. An object of the present invention is to provide a substrate processing method capable of suppressing the formation of the substrate.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a substrate processing method according to the present invention is a method in which a substrate is loaded into the load lock chamber in a method in which the substrate is loaded into the processing chamber via the load lock chamber and then subjected to predetermined processing. The first step of flowing the inert gas from the processing chamber to the load lock chamber by evacuating the load lock chamber while supplying the inert gas to the processing chamber, and during the execution of the first step A second step of carrying the substrate stored in the load lock chamber into the processing chamber, and a third step of performing a predetermined process on the substrate carried into the load lock chamber after the completion of the second step. These steps are provided.
[0012]
In other words, the present invention relates to the inert gas from the processing chamber to the load lock chamber by evacuating the load lock chamber while supplying the inert gas to the processing chamber when the substrate is loaded into the load lock chamber. The flow forming means for forming the flow of the liquid, the carrying means for carrying the substrate stored in the load lock chamber into the processing chamber during execution of the flow forming process of the flow forming means, and the carry-in processing of the carry-in means are completed After that, a substrate processing apparatus provided with processing means for performing a predetermined process on the substrate carried into the load lock chamber is provided.
[0013]
In the above configuration, when a substrate is loaded into the load lock chamber, first, a process of evacuating the load lock chamber is performed while supplying an inert gas to the processing chamber. Next, during the execution of this process, a process of carrying the substrate stored in the load lock chamber into the process chamber is executed. Next, when this process is completed, a predetermined process is performed on the substrate carried into the process chamber.
[0014]
According to such a configuration, when the substrate is transferred from the load lock chamber to the processing chamber, an inert gas flow from the reaction chamber to the load lock chamber is formed. Thereby, it is suppressed that the residual atmosphere (residual moisture, residual oxygen, outgas, etc.) of the load lock chamber is caught in the reaction chamber. As a result, when the substrate is transferred from the load lock chamber to the processing chamber, the formation of a natural oxide film on the substrate is suppressed.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
FIG. 1 is a diagram showing a configuration of an embodiment of a substrate processing apparatus for executing a substrate processing method according to the present invention. In the figure, as a substrate processing apparatus, a thin film forming apparatus for forming a thin film on a wafer of a semiconductor device is shown as a representative. In the figure, a vertical thin film forming apparatus is representatively shown as the thin film forming apparatus.
[0017]
The illustrated thin film forming apparatus 100 forms a reaction vessel 101 for forming a reaction chamber A1 for forming a thin film on a wafer 200, and a load lock chamber A2 for preventing the reaction chamber A1 from coming into contact with the atmosphere. A load lock container 102 and a gate valve 103 for blocking a boat entrance / exit between the reaction container 101 and the load lock container 102 are provided.
[0018]
The thin film forming apparatus 100 shown in the figure, when forming a thin film on the wafer 200, carries a boat 104 for holding the wafer 200, and carries the boat 104 into the reaction chamber A1 or unloads it from the reaction chamber A1. A boat elevator 105.
[0019]
The illustrated thin film forming apparatus 100 includes an air supply pipe 106 and a quartz nozzle 107 for back purging the reaction chamber A1 with N ₂ gas, and an exhaust pipe 108 and a vacuum pump 109 for evacuating the load lock chamber A2. And the air supply pipe 110 for supplying N ₂ gas to the load lock chamber A2, the air valves 111, 112, 113 for shutting off the pipes 106, 108, 110, and the vacuum pressure in the load lock chamber A2 are measured. A vacuum gauge (VAC) 114 for
[0020]
The illustrated thin film forming apparatus 100 includes a control unit 115 that controls the apparatus 100.
[0021]
The reaction vessel 101 is configured by a combination of an outer tube 101a and an inner tube 101b. The load lock container 102 is provided below the reaction container 101. The boat 104 is mounted on a mounting table 105 a of the boat elevator 105. The boat elevator 105 is disposed in the load lock chamber A2. The mounting table 105a of the boat elevator 105 is also used as a sealing lid for sealing the boat loading / unloading port when the boat 104 is carried into the reaction chamber A1.
[0022]
One end of the air supply pipe 106 is connected to one end of the quartz nozzle 107, and the other end is connected to an N ₂ gas tank for back purge (not shown). The air valve 111 is inserted in the air supply pipe 106. The quartz nozzle 107 is provided inside the reaction vessel 101.
[0023]
One end of the exhaust pipe 108 is connected to the side surface of the load lock container 102, and the other end is connected to the vacuum pump 109. The air valve 112 is inserted in the exhaust pipe 108. The vacuum gauge 114 is connected to the exhaust pipe 108 between the load lock container 102 and the air valve 112.
[0024]
One end of the air supply pipe 110 is connected to the side surface of the load lock container 102, and the other end is connected to an N ₂ gas tank for replacement (not shown). The air valve 113 is inserted in the supply air pipe 110.
[0025]
The processing program of the control unit 115 is stored in, for example, the external storage medium 300, and is loaded from the external storage medium 300 to the internal storage medium 115a of the control unit 115 when used. Here, as the external storage medium 300, for example, a CD-ROM is used, and as the internal storage medium, for example, a hard disk is used.
[0026]
In the above configuration, the thin film forming process will be described with reference to FIGS. Here, FIG. 2 is a flowchart showing a process of the control unit 115 for controlling the thin film forming process, and FIG. 3 is a sequence diagram showing the thin film forming process. In these drawings, only the process and the sequence of the part where the wafer 200 is transferred from the load lock chamber A2 to the reaction chamber A1 are shown.
[0027]
In the state where the wafer 200 is loaded into the load lock chamber A2, as shown in FIG. 3A, the gate valve 103 and the air valves 111, 112, and 113 are closed, and the vacuum pump 109 is set to the on state. ing. The atmosphere in the reaction chamber A1 is set to N ₂ gas, and the pressure is set to atmospheric pressure. This is to keep the internal state of the reaction chamber A1 in a stable state by the inert gas. Furthermore, the atmosphere of the load lock chamber A1 is set to air, and the pressure is set to atmospheric pressure. This is because the load lock chamber A <b> 2 is released to the outside by carrying in the wafer 200.
[0028]
In this state, the control unit 115 first performs control to form a flow of N ₂ gas from the reaction chamber A1 to the load lock chamber A2 as shown in FIG. 2 (step S11). By this control, the gate valve 103 and the air valves 111 and 112 are opened as shown in FIG. Thereby, N ₂ gas is supplied to the reaction chamber A1 and the load lock chamber A2 is evacuated. As a result, a flow of N ₂ gas from the reaction chamber A1 to the load lock chamber A2 is formed.
[0029]
Next, during execution of this process, as shown in FIG. 2, the control unit 115 controls to transfer the wafer 200 from the load lock chamber A2 to the reaction chamber A1 (step S12). By this control, the boat elevator 105 is driven up as shown in FIG. As a result, the boat 104 is carried into the reaction chamber A1, and the substrate loading / unloading port is sealed by the mounting table 105a. The carry-in process is performed, for example, with the flow rate of N ₂ gas being about 20 liters per minute and the pressure in the reaction chamber A1 and the load lock chamber A2 being reduced to 100 pa.
[0030]
When this process is completed, the control unit 115 performs control to stop the flow of N ₂ gas from the reaction chamber A1 to the load lock chamber A2 as shown in FIG. 2 (step S13). By this control, the air valves 111 and 112 are closed. Thereby, the flow of N ₂ gas from the reaction chamber A1 to the load lock chamber A2 is stopped.
[0031]
When this processing is completed, the control unit 115 performs control to evacuate the reaction chamber A1 although not shown in FIG. Thereby, reaction chamber A1 is set to a vacuum state. When this process ends, the control unit 115 performs control to form a thin film on the wafer 200, which is not shown in FIG. As a result, a thin film is formed on the wafer 200.
[0032]
According to the embodiment described in detail above, when the wafer 200 is transferred from the load lock chamber A1 to the reaction chamber A2, the load lock chamber A2 is evacuated while supplying N ₂ gas to the reaction chamber A1. Therefore, a flow of N ₂ gas from the reaction chamber A1 to the load lock chamber A2 can be formed.
[0033]
Accordingly, when the wafer 200 is transferred from the load lock chamber A2 to the reaction chamber A1, it is possible to suppress the atmosphere (residual moisture, residual oxygen, outgas, etc.) in the load lock chamber A2 from being caught in the reaction chamber A1. . As a result, when the wafer 200 is transferred from the load lock chamber A2 to the reaction chamber A1, it is possible to suppress the formation of a natural oxide film on the wafer 200.
[0034]
FIG. 4 shows this state. FIG. 4 shows the measurement result C1 of the increase in natural oxide film when the wafer 200 is transferred from the load lock chamber A2 to the reaction chamber A1 by the conventional method, and the wafer 200 is transferred by the method of the present embodiment. The measurement result C2 of the increase amount of the natural oxide film in this case is shown. FIG. 4 shows the measurement results when the temperature of the reaction chamber A1 is set to 700 ° C.
[0035]
As shown in the figure, in the conventional transfer method, a natural oxide film of 0.5 to 1.2 angstrom is formed. On the other hand, in this embodiment, a natural oxide film of 0 to 0.2 angstrom is formed. From this figure, it can be seen that the amount of increase in the natural oxide film can be significantly suppressed in the transport method of the present embodiment as compared with the conventional transport method.
[0036]
Further, according to such a configuration, it is possible to solve the conventional problem mainly by changing the processing program (software) of the control unit 109 without changing hardware. Thereby, the conventional problem can be solved with a simple configuration.
[0037]
As mentioned above, although one embodiment of the present invention was described in detail, the present invention is not limited to the above-described embodiment.
[0038]
For example, in the previous embodiment, the case where the present invention is applied to a thin film forming method using N ₂ gas as an inert gas has been described. However, the present invention can also be applied to a thin film forming method using an inert gas other than N ₂ gas.
[0039]
In the previous embodiment, the case where the present invention is applied to a thin film forming method for forming a predetermined thin film on a wafer has been described. However, the present invention can also be applied to wafer processing methods other than the thin film forming method. For example, the present invention can be applied to an oxide film forming method for forming an oxide film on a wafer and an impurity doping processing method for adding impurity atoms to the wafer.
[0040]
In the previous embodiment, the case where the present invention is applied to a wafer processing method of a semiconductor device has been described. However, the present invention can also be applied to a substrate processing method for processing a substrate other than a wafer. For example, the present invention can be applied to a substrate processing method for processing a glass substrate of a liquid crystal display device.
[0041]
Of course, the present invention can be variously modified without departing from the scope of the invention.
[0042]
【The invention's effect】
According to the present invention described in detail above, when the substrate is transferred from the load lock chamber to the reaction chamber, the load lock chamber is evacuated while supplying the inert gas to the reaction chamber. An inert gas flow can be formed toward the lock chamber. Accordingly, when the substrate is transported from the load lock chamber to the reaction chamber, it is possible to suppress the atmosphere (residual moisture, residual oxygen, outgas, etc.) in the load lock chamber from being caught in the reaction chamber. As a result, it is possible to suppress the natural oxide film from being formed on the wafer by this atmosphere.
[0043]
Further, according to such a configuration, when the substrate processing apparatus is configured to control the processing of the substrate using a computer, the software is mainly changed without changing the hardware so much. Can solve the problem. Thereby, the conventional problem can be solved with a simple configuration.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a flowchart showing processing of a control unit according to an embodiment of the present invention.
FIG. 3 is a sequence diagram showing an operation according to an embodiment of the present invention.
FIG. 4 is a characteristic diagram for explaining the effect of the embodiment of the present invention.
FIG. 5 is a sequence diagram showing an operation of an example of a conventional substrate processing method.
FIG. 6 is a sequence diagram showing the operation of another example of the conventional substrate processing method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Substrate processing apparatus, 101 ... Reaction vessel, 101a ... Outer tube, 101b ... Inner tube, 102 ... Load lock vessel, 103 ... Gate valve, 104 ... Boat, 105 ... Board elevator, 106, 110 ... Air supply piping, 107 DESCRIPTION OF SYMBOLS ... Quartz nozzle, 108 ... Exhaust piping, 109 ... Vacuum pump, 111, 112, 113 ... Air valve, 114 ... Vacuum gauge, 115 ... Control part, 115a ... Internal storage medium, 200 ... Wafer, 300 ... External recording medium, A1 ... reaction chamber, A2 ... load lock chamber.

Claims (2)

In the substrate processing method of performing a predetermined process on the substrate after carrying the substrate into the processing chamber via the load lock chamber,
Wherein after loading the substrate into the load lock chamber, a load lock chamber was evacuated treatment or inert gas atmosphere, the inert gas from the processing chamber by supplying an inert gas into the processing chamber to the load lock chamber A first step of forming a flow of
A second step of carrying the substrate stored in the load lock chamber into the processing chamber during the execution of the first step;
A substrate processing method comprising: a third step of performing a predetermined process on the substrate carried into the processing chamber after the completion of the second step. The substrate processing method according to claim 1, wherein the second step is performed in a state where the processing chamber and the load lock chamber are decompressed.

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