JP3249755B2 - Vapor phase growth method and wafer transfer apparatus used for the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer transfer method for transferring a wafer to a vapor phase growth apparatus and a transfer apparatus used for the method.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, various vapor phase growth apparatuses are used. As a method of transferring the wafer to the vapor phase growth apparatus, there are a method of transferring a wafer by an arm, a method of transferring a wafer in a state where the wafer is vacuum-sucked by a vacuum chuck, and the like. Usually, the transfer of a wafer is performed in a vacuum or a high-purity gas atmosphere, and a reaction gas serving as a material for vapor phase growth is started to flow after the transfer is completed.

[0003]

By the way, in the vapor phase growth apparatus, since the reactive material gas is used as described above,
The generation of the product is inevitable, and the product adheres to the inner wall of the chamber of the vapor phase growth apparatus, and the adhesion of the product increases as the processing is repeated.

[0004] When the adhesion of the product to the inner wall of the chamber or the like increases, the following problem occurs. That is, when a material gas for vapor phase growth is started to flow after the transfer of the wafer, the product is peeled off and flows in the chamber as fine particles due to the turbulence of the gas flow generated at the start of the flow of the reaction gas. Then, the fine particles adhere to the wafer surface as fine dust, which deteriorates the characteristics of the wafer to be obtained as a result, and this is one of the causes of a decrease in yield.

Conventionally, the problem of dust caused by products adhering to the inner wall of the chamber has been performed by periodically cleaning the inside of the chamber. However,
Periodic maintenance of cleaning in the chamber lowers the operation rate of the apparatus, which leads to an increase in the cost of the wafer.

Further, even if the inside of the chamber is washed, the product gradually adheres until the next washing, and it is difficult to avoid the problem of dust without fail. Was.

An object of the present invention is to solve the problem of dust caused by products adhering to the inner wall of a chamber with a simple wafer transfer structure.

[0008]

To achieve the above object, a vapor phase growth method according to the present invention comprises a vapor phase growth chamber and a transfer chamber attached to the vapor phase growth chamber. A step of transferring a wafer or a wafer holder from the substrate into the chamber for vapor phase growth, wherein the vapor phase
A first step of flowing the same amount of a non-reactive gas into the chamber for vapor phase growth from a gas pipe provided in the long chamber, and a wafer from the transfer chamber after the first step. Alternatively , a second step of transferring the wafer holder into the vapor phase growth chamber, and after the second step,
No flow disturbance occurs and the gas flow rate becomes substantially constant before the transfer.
In this manner, the non-reactive gas is switched to a reactive gas to perform vapor phase growth.

As described above, before the vapor phase growth step, the vapor phase
Since the same amount of non-reactive gas flows into the chamber for vapor phase growth from the gas pipe provided in the long chamber, the same amount of non-reactive gas as in the vapor phase growth is generated, so that the gas flow generated when the reaction gas is started to flow conventionally The deposits that easily fall off from the inner wall of the chamber due to the turbulence are removed in advance by the inflow and exhaust of the gas performed before the vapor phase growth.
Also, when the gas for vapor phase growth is introduced,
Gas flow is almost constant from before transporting without flow disturbance
As described above, since the non-reactive gas is switched to the reactive gas, the adhered substance does not peel off from the inner wall of the chamber due to the turbulence of the air flow.

[0010] Further, as a wafer transfer device used in the vapor phase growth method, an arm for contacting a wafer or a wafer holder, and a transfer of the wafer or the wafer holder from the transfer chamber side fixed to the arm. the withdrawn from the vapor phase growth chamber after row <br/> lines have conveyed
And a dust cover that covers the surface of the wafer is provided above the arm.

Therefore, even if there is dust floating in the chamber or the transfer chamber during the transfer of the wafer or the wafer holder, it can be prevented from adhering to the wafer.

Further, characterized in that the upper surface of the dust cover is inclined such that lower in the direction of the conveying rod. This causes dust to adhere to the dust cover
And that this dust could spill further
However, the direction in which the dust falls is
Can be limited, avoid falling on the wafer
it can. Further, a dust cover and the wafer or the wafer may be provided.
Introduce an unreacted gas between the chamber and the holder.
It is characterized by having. This allows the dust cover
Dust adheres to it, and this dust spills out further
If so, it can be swept out of the wafer
it can. A chamber for vapor phase growth and a chamber for vapor phase growth
And a transfer chamber attached to the chamber.
Place the wafer or wafer holder on the vapor phase growth chamber.
In a vapor phase growth method having a step of transporting into a bar,
Before the vapor growth step,
First step of flowing the same amount of non-reactive gas as during vapor phase growth
And after the first step, a wafer or wafer is transferred from the transfer chamber.
Conveying the chamber holder into the chamber for vapor phase growth
A second step, and reacting the non-reactive gas after the second step.
Switch to gas and use for vapor phase growth method for vapor phase growth
Wafers or Wafers
An arm for contacting the holder, and fixed to the arm
From the transfer chamber side to the wafer or wafer holder
A transfer rod for performing transfer, and a transfer rod at an upper part of the arm.
Provide a dust cover to cover the wafer surface, and
So that the upper surface of the strike cover is lowered in the direction of the transport rod
Tilt the top of the dust cover,
The airflow flowing into the chamber flows in the direction of the transport rod.
As described above, substantially perpendicular to the upper surface of the dust cover and the
That an airflow adjustment plate that is substantially parallel to the longitudinal direction of the
Features.

For this reason, if the wafer or the wafer
Floating in the chamber or transfer room when transferring the carrier
Dust that may adhere to the wafer
And can be prevented. Furthermore, even if dust adheres to the dust cover and the dust may spill down, the direction in which the dust falls can be limited to the direction in which the transport rod is pulled out, and the dust falls on the wafer. Can be avoided.

[0014]

[0015]

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
This will be described with reference to FIG. FIG. 1 is a perspective view of a wafer transfer apparatus according to the present embodiment, and FIG. 2 is an enlarged view of a wafer transfer unit used in the apparatus of FIG.

As shown in FIG. 1, the wafer transfer apparatus according to the present embodiment has a chamber 1 for performing a film forming process by vapor phase growth and a load chamber 3 for transferring a wafer 2 into the chamber 1. It is composed of An inflow gas pipe 4 through which gas flows into the upper part of the chamber 1.
However, an exhaust gas pipe 5 is provided at a lower portion thereof. Inside the chamber 1, a wafer mounting portion 6 for mounting a wafer is provided. Reference numeral 7 denotes a gate valve for freely separating the chamber 1 from the load chamber 3, and reference numeral 8 denotes a transfer rod for transferring a wafer into the chamber 1.

As shown in FIG. 2, a transfer arm 9 is provided at the tip of the transfer rod 8, and the wafer 2
A dust cover 10 is provided so as to cover the upper part. The dust cover 10 is made of a transparent material to facilitate operability and trouble handling during manual conveyance. Reference numeral 11 denotes a tray on which the wafer 2 is mounted.

Next, the transport method of the present invention using the above-described apparatus will be described. First, a tray 11 on which a plurality of wafers 2 are mounted (hereinafter, represented by the tray 11) is carried into the load chamber 3. At this time, the same amount of non-reactive gas, for example, purified hydrogen gas, nitrogen gas, or inert gas that flows into the chamber 1 from the inflow gas pipe 4 in the subsequent film forming process, while exhausting gas, The non-reactive gas is exhausted from the gas pipe 5.

As a result, the deposits which had been easily separated from the inner wall of the chamber 1 by the turbulence of the gas flow generated when the reactant gas for the gas phase growth was started to flow before the gas phase growth were formed. It is removed in advance by the inflow and exhaust of the non-reactive gas.

Next, after the tray 11 is carried into the chamber 1, only the transfer rod 8 is pulled out and the gate valve 7 is closed. Then, the non-reactive gas is switched to a reactive gas, and a film forming process for vapor phase growth is started. Here, since the gas flow rate in the chamber 1 is substantially constant before the transfer, the gas flow is not disturbed, and the problem of separation of the product due to the gas flow disturbance does not occur here.

Further, even if a slight turbulence of the gas flow is generated and fine dust is generated, in this embodiment, since the dust cover 10 disposed on the wafer 2 is provided, Does not adhere to the surface of

Therefore, the influence of dust caused by products adhering to the inner wall of the chamber 1 can be reduced. In addition, the burden of maintenance such as chamber cleaning can be reduced, and the operation rate of the apparatus can be improved.

FIGS. 3 and 4 are a perspective view and a longitudinal sectional view of a wafer transfer section according to another embodiment of the present invention. The structure of this embodiment is different from the structure of FIG. 2 in that a non-reactive gas is introduced between the dust cover 10 and the tray 11 by the gas introduction pipe 12. Other structures and a manufacturing method using this device are the same as those in FIGS.

According to this structure, dust is generated due to slight turbulence of the gas flow, and even if the dust reaches not only the upper portion of the dust cover 10 but also the lower portion thereof, the dust is removed by the non-reactive gas 13. Can be swept out.

FIGS. 5 and 6 are a perspective view and a view for explaining the function of a wafer transfer section according to still another embodiment of the present invention. In the present embodiment, as shown in FIG. 5, the dust cover 10 is inclined so as to become lower toward the conveying rod 8. Other structures and a manufacturing method using this device are the same as those in FIGS.

This structure takes into account problems that may occur in the structures of FIGS. 1 and 2 and takes measures to address them. That is, according to the transport method shown in FIGS. 1 and 2, generation of dust can be suppressed, and even if dust is generated, the dust can be prevented from accumulating on the dust cover 10. However, after the tray 11 is mounted on the wafer mounting section 6 in the chamber 1, only the transfer rod 8 (and the transfer arm 9) is pulled back toward the load chamber. At this time, dust accumulated on the dust cover 10 is removed. It is also conceivable that the ink spills onto the tray 11.

Therefore, the present embodiment provides a structure that does not fall at least on the tray 11 even if the dust spills out of the dust cover 10. That is, as described above, by providing the dust cover 10 with an inclination and lowering the side of the transport rod 8, the flow of the non-reactive gas 13 passing over the dust cover 10 flows in the direction in which the transport rod 8 is pulled. I have to. According to this structure, even if dust spills out of the dust cover 10, it does not accumulate on the tray 11. Therefore, the yield can be more reliably improved than the structure shown in FIGS.

FIGS. 7 and 8 show a further improvement of the structure of the transfer section shown in FIGS. That is, as shown in FIGS. 7 and 8, a gas flow adjusting unit 14 substantially parallel to the longitudinal direction of the transport rod 8 is further provided on the dust cover 10 inclined so as to be lower in the direction of the transport rod 8. Reaction gas 1
3 is configured to surely flow in the direction of the transport rod 8.

[0030]

As described above, according to the vapor phase growth method of the present invention, the deposits that easily fall off from the inner wall of the chamber are transferred to the vapor phase growth chamber before the vapor phase growth.
Since the non-reactive gas is previously removed by flowing and exhausting the non-reactive gas from the provided gas pipe , it is possible to prevent dust from adhering to the wafer. In addition, there is no
Is changed to a non-reactive gas so that the gas becomes substantially constant, and a gas for vapor phase growth is introduced, so that even at the time of this switching, there is no possibility that the extraneous matter will come off from the inner wall of the chamber.

Further, since a dust cover for covering the wafer surface is provided as a wafer transfer device used in the above-mentioned vapor phase growth method, if a wafer is transferred,
Even if there is dust floating in the chamber or the transfer chamber, it can be prevented from adhering to the wafer. Ma
Also, make sure that the top surface of the dust cover is
Inclined, on the top surface, almost perpendicular to the top surface of the dust cover
And an airflow adjusting plate substantially parallel to the longitudinal direction of the transport rod is provided.
So, further, dust adheres to the dust cover,
And even if this dust could fall off
The direction in which the dust falls is limited to the direction in which the transport rod is pulled out.
To avoid falling on the wafer
Wear.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a vapor deposition method according to an embodiment of the present invention.

FIG. 2 is a perspective view of a wafer transfer device used in the vapor phase growth method of FIG.

FIG. 3 is a perspective view of a wafer transfer device according to another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of the transfer device of FIG. 3;

FIG. 5 is a perspective view of a wafer transfer device according to still another embodiment of the present invention.

FIG. 6 is a perspective view for explaining the effect of the transport device of FIG. 5;

FIG. 7 is a perspective view of a wafer transfer device according to still another embodiment of the present invention.

FIG. 8 is a perspective view for explaining the effect of the transport device of FIG. 7;

[Explanation of symbols]

 Reference Signs List 1 chamber 2 wafer 3 transfer chamber (load chamber) 8 transfer rod 9 arm 10 dust cover 11 wafer holder (tray) 13 non-reactive gas 14 airflow adjustment plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI H01L 21/68 H01L 21/68 A (58) Investigated field (Int.Cl. ⁷ , DB name) H01L 21/205 B65G 49 / 07 C23C 14/56 C23C 16/44 C30B 35/00 H01L 21/68

Claims (5)

(57) [Claims] 1. A process comprising a chamber for vapor-phase growth and a transfer chamber attached to the chamber for vapor-phase growth, comprising a step of transferring a wafer or a wafer holder from the transfer chamber into the chamber for vapor-phase growth. In the vapor phase growth method, it is set in the vapor phase growth chamber before the vapor phase growth step.
A first step of flowing the same amount of a non-reactive gas as in the vapor phase growth into the vapor phase growth chamber from the opened gas pipe, and after the first step, a wafer or a wafer holder from the transfer chamber Transporting into the chamber for vapor phase growth
And after the second step, the turbulence of the gas flow does not occur and the gas flow rate becomes
A vapor phase growth method , wherein the non-reactive gas is switched to a reactive gas so as to be substantially constant before the transportation , and vapor phase growth is performed. 2. A wafer transfer apparatus used in the vapor phase growth method according to claim 1, wherein said arm is provided for contacting a wafer or a wafer holder, and said wafer or said wafer is fixed to said arm from said transfer chamber side. withdrawn from the vapor phase growth chamber after the transport have rows conveyance of the wafer holder
A transfer rod, and a dust cover for covering a surface of the wafer is provided above the arm. 3. The wafer transfer device according to claim 2, wherein an upper surface of the dust cover is inclined so as to be lower in a direction of the transfer rod. 4. The wafer transfer apparatus according to claim 2, further comprising an introduction pipe for introducing a non-reactive gas between said dust cover and said wafer or wafer holder. 5. A vapor phase growth chamber and a vapor phase growth chamber.
And a transfer chamber attached to the chamber.
Place the wafer or wafer holder on the vapor phase growth chamber.
In a vapor phase growth method having a step of transporting into a bar,
Before the vapor growth step,
First step of flowing the same amount of non-reactive gas as during vapor phase growth
And after the first step, a wafer or wafer is transferred from the transfer chamber.
Conveying the chamber holder into the chamber for vapor phase growth
A second step, and reacting the non-reactive gas after the second step.
Switch to gas and use for vapor phase growth method for vapor phase growth
A wafer transfer device that is, the arm for contacting a wafer or wafer holder
And the wafer fixed to the arm from the transfer chamber side.
Or, a transfer rod for transferring the wafer holder is provided.
The upper part of the arm has a wafer covering the surface of the wafer.
Cover, and the upper surface of the dust cover is
And the airflow flowing into the chamber for vapor phase growth flows in the direction of the transport rod on the upper surface of the dust cover, so as to be substantially perpendicular to the upper surface of the dust cover, and features and to roux Eha conveying device in that a longitudinal direction substantially parallel to the air flow adjusting plate of the transport bar.