JPS63211643A - Wafer transfer device for semiconductor wafer processor - Google Patents

Abstract

PURPOSE:To transfer a wafer safely without the possibility of damage by conducting the delivery of the wafer between a wafer carrier and a fork and its transfer between the wafer carrier and a reaction chamber by the cooperative operation of a carrier lifting mechanism and a fork moving mechanism. CONSTITUTION:Wafers 7 are delivered between a wafer carrier 6 and a fork 9 in a soft handling system in a wafer transfer process. Since the wafers 7 are scooped up from the wafer carrier 6 as they are left as they are positioned at a horizontal position and carried onto the fork 9, even the wafers having a large diameter can be handled without the possibility of damage. The fork 9 is turned and operated centering around a driving shaft 11 by a rotational drive mechanism 25 in a reaction chamber in response to processing processes, thus changing the directions of the wafers 7 carried onto the fork up to an approximately vertical angle from a horizontal wafer position.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to etching/CVD for semiconductor wafers,
The present invention relates to a wafer transfer device incorporated into a wafer processing device that performs various process steps such as epitaxial growth.

[Conventional technology]

In the wafer processing equipment that performs the process steps mentioned above,
In order to prevent the process reaction chamber, which is maintained under vacuum, from being exposed to the atmosphere, a load lock chamber is provided as a preliminary evacuation chamber at the front stage of the reaction chamber.

To perform wafer processing here, first a wafer carrier loaded with multiple wafers is carried into a load lock chamber, then one wafer is taken out from the wafer carrier and transferred to a reaction chamber, and the necessary processes are carried out within the reaction chamber. After the wafer is processed, it is necessary to carry out a transfer operation in which the wafer is returned from the reaction chamber to the load lock chamber and transferred to the wafer carrier.

On the other hand, as a wafer transport device for carrying out the above-described wafer transport, various transport systems such as belt transport and cylinder transport are conventionally known. In the belt transport method, a wafer transport belt is laid between the load lock chamber and the reaction chamber, and each wafer is scooped up one by one from a wafer carrier and placed on the transport belt and transported into the reaction chamber. In the cylinder transfer method, the drive shaft of a cylinder installed outdoors is pulled into the room via an O-ring, and a hand mechanism for gripping the outer periphery of the wafer is attached to the tip of the shaft.

(Problem to be solved by the invention) In recent years, along with advances in process technology, semiconductor wafers have become larger in diameter, patterns formed on the wafer surface have become finer, and the degree of integration has increased. Demand for indoor cleanliness and soft handling of large-diameter wafers is increasing.

In this regard, the conventional wafer transfer apparatus described above has the following problems. In other words, in the former belt S feeding method, since the drive system mechanism is installed indoors, a lot of dust is generated from the belt due to the belt drive.
Oil etc. are generated and contaminate the room, reducing the cleanliness of the room. Furthermore, since belts are limited to horizontal conveyance, they are not suitable for process steps in which the wafer position is changed from horizontal to nearly vertical, for example when supplying a plasma flow from the side to a reaction chamber in a plasma flow CVD process. I can not cope.

In addition, in the latter cylinder transport method, the rubber O-ring that seals the boundary between the inside and outside of the room wears out during long-term use, causing dust to contaminate the room. Soft handling is difficult because there is a risk of damaging large-diameter wafers.

The purpose of this invention is to eliminate the risk of generating dust, etc. that can cause indoor contamination when wafers are transferred in a wafer processing device, to enable soft handling of large-diameter wafers, and to allow wafers to be placed in the wafer transfer position if necessary. An object of the present invention is to provide a wafer transfer device which can easily change a wafer from a horizontal position to a vertical position within a reaction chamber, thereby solving the conventional problems.

[Means for solving problems]

In order to solve the above problems, the present invention provides a carrier lifting mechanism that lifts and lowers a wafer carrier carried into a load lock chamber using an actuator that is isolated from the room and placed outside the room, and a wafer carrier that is connected to the tip of the load lock chamber. A fork moving mechanism is provided that reciprocates the carrying fork between the reaction chamber and the load lock chamber using an actuator that is isolated from the indoor side and placed on the outdoor side, and the carrier lifting mechanism and the fork moving mechanism are jointly operated. The wafer is transferred between the wafer carrier and the fork, and transported between the reaction chamber and the reaction chamber.

[Effect]

In the above configuration, the carrier lifting mechanism supports the wafer carrier carried into the load lock chamber.

The wafer transfer position between the wafer carrier and the fork is adjusted by the vertical movement operation. Further, the fork moving means moves the wafer carried by the fork back and forth between the wafer carrier in the load lock chamber and the process reaction chamber by moving forward and backward. By jointly operating the carrier lifting mechanism and the fork moving mechanism, the wafers housed in the wafer carrier are delivered to the fork one by one in a soft handling manner, and are further transferred to and from the reaction chamber. The stone is pulled in and transported back.

Furthermore, the drive actuators of the carrier lifting and lowering mechanisms and wafer moving mechanisms are isolated outside the room via, for example, magnetic couplings as power transmission means, and foreign matter such as dust and oil generated from the drive actuator side is removed from the process. There is no risk of contaminating the inside of the device.

〔Example〕

1 to 5 show the configuration of a wafer transfer device according to an embodiment of the present invention incorporated into a semiconductor wafer processing device. First, the configuration of the entire device will be explained with reference to FIG. Process equipment main container, 2
is the load lock chamber, 3 is the process reaction chamber, and the load lock chamber 2 is in front of it! s4, and a partition door 5 is installed between the load lock chamber 2 and the reaction chamber 3.

Although not shown, an exhaust system is connected to each chamber 2.3. Further, 6 indicates a wafer carrier carried into the load lock chamber. 8 The wafer carrier 6 is a transportable case in which a specified number of semiconductor wafers 7 are housed in a horizontal position in multiple vertical stages, and the above-mentioned door 4 into and out of the load lock chamber 2.

On the other hand, the load-lock chamber 2 has a carrier elevating mechanism 8 mounted on the bottom side thereof with the wafer carrier 6 for lifting and lowering operations, and a fork 9 for supporting a wafer connected to the tip of the reaction chamber 3 on the rear side. A fork moving mechanism 10 is installed to move the fork horizontally between the load lock chamber 2 and the reaction chamber 3 through the field 5. Note that 5a is an actuator for opening/closing the door 5 installed outside the room, and 3a is an inlet for plasma flow opened on the side of the reaction chamber 3.

Next, the above-mentioned fork 9. and carrier lifting mechanism 8.
The detailed structure of the fork moving mechanism 10 will be described. First, as shown in FIGS. 2 to 4, the fork 9 is provided with claws 9b corresponding to the external shape of the semiconductor wafer 7 at three locations at the tip of a cross-shaped frame 9a.

The rear end of the frame 9a is connected to a drive shaft of a fork moving device, and the semiconductor wafer 7 is fitted between the claws 9b and held at a fixed position on the frame 9a. The figure shows a conveyance state in which the semiconductor wafer 7 is held in a horizontal position. From this state, by rotating the fork 9 around the axis in the direction of the arrow, the holding position of the wafer can be changed while holding the semiconductor wafer 7. The angle can be changed from horizontal to nearly vertical.

Further, in the fork moving mechanism 10 for moving and operating the fork 9, as shown in FIG. The airtight container 12 is housed in a long non-magnetic airtight container 12 coupled to the reaction chamber along the path.
A drive actuator 15 including a drive motor 13 and a screw feed mechanism 14 is installed separately from the reaction chamber, and a magnetic coupling 16 serving as a power transmission means is provided between the drive shaft 11 and the drive actuator 15. are magnetically coupled via. The magnetic coupling 16 includes a driven side magnet 17 connected to the shaft end of the drive shaft 11, and a driving side magnet 1 facing the outer circumferential side of the airtight container 12.
8, an inner housing 19 holding the magnet 18, and an outer housing 20 holding the inner housing 19 rotatably.
The screw feed mechanism 14 is connected to the screw feed mechanism 14 of Note that 21 is a magnetic shield surrounding the drive side magnet 1, and 22 is an airtight container 1.
This is a greaseless fixed sliding type bearing in which a drive shaft 11 and a magnet 17 are movably supported within the bearing. The housing 19 also includes a drive motor 23. A rotational drive mechanism 25 consisting of a gear mechanism 24 is connected.

With this configuration, the drive motor 13 of the drive actuator 15
By threading the outer housing 20 of the magnetic coupling 16 at the drive side magnet 18. The fork 9 is moved horizontally in the direction of the arrow along with the drive shaft 11 via the driven side magnet 17, and in this process, the inner housing 19 is rotated by operating the rotary drive mechanism 25, and the fork is moved via the magnetic coupling 16. 9 changes direction around the drive shaft 11 in the direction of arrow B.

On the other hand, the carrier lifting mechanism 8 is connected to a carrier support stand 26 disposed inside the chamber to place and support the wafer carrier 6 carried into the load lock chamber 2, and lifts and lowers the support stand in the direction of arrow C inside the room. The mechanism is similar to the fork moving mechanism described above, in which a drive actuator placed separately outside the room and a drive shaft of the carrier support base 26 are coupled via a magnetic coupling. Here, the difference from the fork moving mechanism 10 shown in FIG. It consists of a structure connected to 14.

Next, the wafer transport operation in the semiconductor wafer processing step with the above configuration will be explained. First, the specified number of wafers 7
The wafer carrier 6 loaded with the wafer carrier 6 is carried into the load lock chamber 2 and placed on the carrier support stand 26. Now close the front door 4 and load lock chamber 2. After evacuating the process reaction chamber 3, the partition door 5 is opened, and the fork moving mechanism 10 is opened.
is operated to send the fork 9 waiting in the reaction chamber into the load lock chamber 2 and stop it directly below the wafer 7. Next, operate the carrier lifting mechanism 8 to lift the wafer carrier 6.
By slightly moving the wafer carrier 6 downward,
The wafer 7 housed therein is scooped up by the fork 9, fitted between the claws 9b in a horizontal position, and held at a fixed position on the fork.

Subsequently, the fork moving mechanism 10 is operated to pull the wafer 7 together with the fork 9 into the reaction chamber 3 and stop it at a predetermined position, and after the partition door 5 is closed, the inside of the reaction chamber 3 is further evacuated to a high degree of vacuum. This prepares the process step.

Next, the wafer 7 is subjected to low pressure CVD and plasma C in the reaction chamber.
A wafer process such as VD, plasma CVD, or etching is performed. Note that the illustration shows the case of a plasma flow CVD process, and the fifth
By the rotational operation of the rotary drive mechanism 25 described in the figure, the wafer 7 and the fork 9 are turned from a horizontal position to an angle close to a right angle, and the wafer is processed in this state.

When the predetermined wafer process is completed, the rotation drive mechanism 25 returns the wafer 7 from the vertical angle to the horizontal position, and the fork moving mechanism 10 is operated to move the wafer 7 back to the horizontal position.
After the wafer 7 is transported from the reaction chamber to the wafer carrier 6 through the wafer 7, the wafer carrier 6 is slightly raised by operating the carrier lifting mechanism 8, and the wafer 7 is transferred from the fork 9 to the wafer carrier 6. Move back for a while. This completes the process steps for one sheet and its transportation.

To process another wafer next, the wafer carrier 6 is raised and lowered by one pitch using the carrier lifting mechanism 8, and the wafer 7 to be processed next is transferred to the transfer position with the fork 9, and then the same process as above is performed. The wafers are delivered and transferred in the same order as before, and the same operations are repeated to process all the wafers loaded in the wafer carrier 6. When the processing of all wafers is completed, the fork 9 is retreated into the reaction chamber, the partition door 5 is closed, and the atmosphere inside the load lock chamber 2 is replaced with an inert gas, and then the inside of the chamber is returned to the atmosphere. Then, the front surface rR4 is opened and the rewafer carrier 6 is carried out from the load lock chamber 2, and the wafer processing for one set is completed.

Also, as is clear from the above explanation, in the wafer transfer process,
The wafer 7 is transferred between the wafer carrier 6 and the fork 9 in a soft handling manner. Moreover, since the wafer 7 is scooped up from the wafer carrier 6 and carried on the fork 9 in a horizontal position, even large diameter wafers can be handled without fear of damage. Depending on the process step, the fork 9 is rotated around the drive shaft 11 by the rotary drive mechanism 25 in the reaction chamber, so that the wafer 7 carried on the fork is oriented from a horizontal transport position to an almost vertical angle. It is possible to change.

Further, the carrier lifting mechanism 8. The fork moving mechanism 10 has a magnetic coupling 16 in the middle of its power transmission path.
By installing the drive actuator 15 outside the room and separating it from the room of the airtight container, there is a risk that foreign substances such as dust and oil generated on the drive actuator side may enter the room of the process equipment and cause contamination. It is possible to maintain the cleanliness of the room without any problems.

〔Effect of the invention〕

As described above, according to the present invention, the wafer carrier transported into the load lock chamber is isolated from the chamber and is lifted and lowered by an actuator placed outside the chamber, and the carrier lifting mechanism A is operated, and the wafer carrying fork is connected to the tip of the carrier lifting mechanism. a fork moving mechanism that moves the wafer carrier back and forth between the reaction chamber and the load lock chamber using an actuator placed outside the room and isolated from the indoor side; By configuring the system to transfer wafers between the wafer carrier and fork and the reaction chamber, a simple transfer mechanism allows wafers to be transferred between the wafer carrier and fork in a soft handling manner. , wafers can be transported safely without fear of damage. Furthermore, by rotating the fork around the drive shaft according to the process step, the wafer orientation can be easily changed from the horizontal transport orientation to a nearly vertical angle convenient for the process.

Moreover, the drive actuators for the carrier lifting mechanism and fork moving mechanism are installed separately outside the process equipment, so there is no risk of foreign matter such as dust or oil generated on the drive actuator side entering the room and contaminating the room. It is possible to provide a wafer transfer device that has high practical value and can sufficiently cope with process steps for large-diameter, highly integrated wafers, such as by being able to maintain indoor cleanliness of the process device.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of the entire wafer transfer device according to an embodiment of the present invention incorporated into a wafer processing device, and FIGS. 2 to 4 are a plan view, a side view, and a partially enlarged view of the fork in FIG. 1, respectively. FIG. 5 is a sectional view showing the detailed structure of the fork moving mechanism in FIG. 1. In each figure, 1: semiconductor wafer processing equipment, 2: load lock chamber, 3: process reaction chamber, 6: wafer carrier, 7:
Wafer, 8: carrier lifting mechanism, 9: fork, 10;
Fork moving mechanism, 11: Drive shaft, 12: Airtight chamber, 15
: drive actuator, 16: ttt coupling,
25: Rotation drive mechanism. Figure 1

Claims (1)

[Claims] 1) Wafer transport in which wafers are taken out one by one from the wafer carrier and transported between a wafer carrier carried into a load lock chamber of a semiconductor wafer processing device and a process reaction chamber adjacent to the load lock chamber. The device consists of a carrier lifting mechanism that separates the wafer carrier carried into the load lock chamber from the inside and lifts and lowers it using an actuator placed outside the room, and a wafer carrying fork connected to the tip that is isolated from the inside of the room. It is equipped with a fork moving mechanism that reciprocates between the reaction chamber and the load lock chamber using an actuator installed on the outside of the room, and the carrier lifting mechanism and the fork moving mechanism jointly operate to move the wafer carrier and the fork. A wafer transfer device for a semiconductor wafer processing device, characterized in that the wafer is delivered and transferred to and from a reaction chamber. 2) In the wafer transfer device according to claim 1, the carrier lifting mechanism and the fork moving mechanism connect the drive actuator located on the outdoor side and the drive shaft on the indoor side across an airtight container that separates the indoor and outdoor areas. A wafer transfer device for a semiconductor wafer processing device, characterized in that it is equipped with a magnetic coupling interposed as a power transmission means between the wafer transfer devices. 3) The wafer transfer device according to claim 2, characterized in that the actuator of the fork moving means includes a rotational drive mechanism that changes the direction of the fork from a horizontal position to a substantially vertical position around an axis. Wafer transport device for semiconductor wafer processing equipment. 4) A semiconductor wafer processing apparatus according to claim 1, wherein the fork is provided with claws that engage with the outer shape of the wafer that supports the wafer at a predetermined position on the fork. wafer transport equipment.