JPH0294647A - Wafer treatment apparatus - Google Patents

Abstract

PURPOSE:To prevent dust particles from adhering and a wafer from being contaminated by a method wherein a treatment and an operation in individual units are executed in a necessary prescribed atmosphere and the wafer is shifted between the individual units in a vacuum state. CONSTITUTION:Untreated wafers 23 are taken out from a loading unit 2 by using a first handling unit 13; they are fed one after another; whenever each treatment is finished, they are fed in succession to a treatment in a next process by using a second handling unit 14; the wafers whose treatment has been completed are housed in an unloading unit 3. These wafers are sfifted between individual units via a Conveyance unit 1 and in a vacuum. Thereby, it is possible to prevent the wafers from being contaminated between the individual treatments and to prevent dust particles from adhering; a high quality can be realized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wafer processing apparatus used for manufacturing semiconductor devices from wafers, particularly for processes that require processing in a specific atmosphere such as a low-pressure gas atmosphere. The present invention relates to wafer processing equipment used, for example, in dry etching, CVD (chemical vapor deposition), and the like.

[Prior Art] Conventional wafer processing apparatuses include batch type and single wafer type.

Both batch and single wafer systems are processing equipment that processes one process, and the batch system processes multiple wafers by simultaneously storing them in a processing chamber such as a vacuum container. In this method, each sheet is stored in a processing chamber and processed.

[Problems to be Solved by the Invention] However, the batch method and single wafer method described above have the following disadvantages.

In recent years, the degree of integration of LSIs has become higher and higher, and very large scale integrated circuits (VLSIs) have also been manufactured.As the degree of integration of LSIs has increased, wafers have also become larger. Therefore, in the batch method in which a plurality of wafers are stored and processed at a time, the processing equipment becomes large and difficult in terms of cost and space. Furthermore,
Higher integration density also requires higher precision in processing equipment and higher quality products, but in batch systems, variations occur due to the position of the wafers.

In addition, in the single-wafer system, since processing is performed one by one, the number of sheets processed per hour (throughput 1) is low, resulting in poor production efficiency.

Furthermore, in both cases, when the necessary processing is completed, the wafer is taken out of the processing chamber and sent to the next processing step, but in the case of ultra-LSI
In manufacturing semiconductor devices such as wafers, the wafer must go through many different processing steps, but during transportation between processing steps, dust and contamination may occur, leading to product defects and quality deterioration. It was causing this.

In view of these circumstances, it is an object of the present invention to provide a wafer processing apparatus that can prevent dust adhesion, contamination, etc., achieve high throughput, and perform processing with high quality and high efficiency.

[Means for Solving the Problems] The present invention provides a transfer unit having an airtight interior, a plurality of handling units provided therein, and a storage stage for temporarily storing wafers between the handling units. The present invention is characterized in that necessary units such as a wafer processing unit 50 corresponding to the handling unit are connected to each other via a vacuum gate valve, the inside of which is airtight.

[Function] Each unit becomes an independent airtight chamber with a vacuum gate valve, and processing and operation in each unit is performed in the required specified atmosphere, and wafers are transferred between each unit in a vacuum state. The movement of wafers between handling units is relayed by a storage stage.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, 1 is a transport unit, 2 is a load unit, 3 is an unload unit, 4 is a first processing unit, 5 is a second processing unit, 6 is a third processing unit, All of these have a configuration in which various devices are housed in a vacuum container.

Further, the load unit 2 is airtightly connected to the transfer unit 1 via a vacuum gate valve 7, and the unload unit 3 is connected to the transfer unit 1 at a position facing the load unit 2 via a vacuum gate valve 8. . first processing unit 4,
The second processing unit 5 and the third processing unit 6 are arranged equidistantly from each other with a second handling mechanism 14 (described later) as the center, and a vacuum gate valve 9. iQ, connected to the transport unit 1 via 11.

Next, the transport unit 1, the loading unit 2, the unloading unit 3, the first processing unit 4, and the second processing unit 5
, and the third processing unit 6 will be explained.

Handling units 1 to 13 are provided at intermediate positions between the loading unit 2 and the unloading unit 3 in the vacuum container 12 of the transfer unit 1, and the first processing unit 4 and the second
The second processing unit 5 and the third processing unit 6 are located at the center of the arrangement.
A handling unit 14 is provided. Between the first handling unit 13 and the second handling unit 14,
Storage stage 15 from the first handling unit 13 side
, an optical sensor unit 16, and an alignment unit 17 are provided.

As shown in FIG. 6, the first handling unit 13 includes a main body 18 housing a drive mechanism, a rotating seat 19 rotatably provided on the main body 18, and a rotary seat 19 rotatably provided on the rotating seat 19. 1 arm 20, a second arm 21 rotatably provided on the first arm 20, and a gret arm 22 rotatably provided on the second arm 21, and the drive mechanism includes a rotary seat 19 and each arm. 20, 21, and 22 are driven independently, and in particular, the first arm 20, second arm 21, and plate arm 22 cooperate with each other so that the plate arm 22 moves in a straight line. ing.

Next, the storage stage 15 lifts and lowers the storage cassette 24, which can store the wafers 23 (see FIG. 6) in three positions: upper stage, middle stage, and lower stage, and allows the wafers 23 to pass through each position, using the lifting drive mechanism 25. This is a possible configuration.

The optical sensor unit 16 has a space 28 through which the wafer 23 and the plate arm 22° can pass, and has a light emitting element such as a light emitting diode, a phototransistor, and a light receiving element on a circumference having the same diameter as the outer circumference of the wafer 23. 2
Four pairs of 6a, 26b, 26c, and 26d, and one pair 27 at the center of the sensor unit 16, each with a wafer 2
3 passing paths are provided in between.

Further, the alignment unit 17 has the function of rotating and raising/lowering the wafer mounting plate 29.

Further, the second handling unit 14 has the same structure as the first handling unit 13, except that a notch 30 is provided so that the plate arm 22' does not interfere with the wafer mounting plate 29.

The load unit 2 maintains the posture of the wafer cartridge 31 in the vacuum container at a 90° angle as shown in FIGS. 3 and 4.
° It is equipped with a support rotation mechanism 32 to be replaced and a lift 81 horizontal 33 (FIG. 5) for raising and lowering the support rotation mechanism 32, and the vacuum container has an opening through which the wafer cartridge 31 can be taken in and taken out. A lid (both not shown) is provided that can open and close the opening and maintain airtightness in the closed state.

A shaft 35 is rotatably provided on the lifting board 34 of the support rotation mechanism 32, and an L-shaped rotating board 36 is fixed to the shaft 35. By rotating the shaft 35 with a required means such as a motor, the wafer can be moved. The attitude of the cartridge 31 is changed.

Next, the elevating mechanism 33 will be explained.

A guide rod 38 is provided vertically downward on the bottom plate 37 of the vacuum container, a pedestal 39 is fixed to the lower end of the guide rod 38, and a slider 41 is slidably provided on the guide rod 38 via a bearing 40. A screw rod 42 is rotatably provided on the pedestal 39 in parallel with the guide rod 38, and the screw rod 42 is connected to the worm gear 4.
3 and is rotated by a motor 44, and is screwed into a nut 45 provided on the slider 41.

A hollow support 46 that airtightly covers the screw rod 42 is erected on the pedestal 39 so as to loosely pass through the bottom plate 37, and the periphery of the support 46 is airtightly covered by a bellows 47.

By driving the motor 44, the screw rod 42 can be rotated via the worm gear 43, and the slider 41, that is, the support rotation mechanism 32 can be raised and lowered.

Since the first processing unit 4, the second processing unit 5, the third processing unit, etc. have an intermediate configuration, the first processing unit 4 will be explained below.

As described above, the first processing unit 4 is a vacuum container and is configured to be airtight inside, and the inside of the first processing unit 4 and the inside of the transfer unit 1 are communicated via the vacuum gate valve 9. .

A wafer support mechanism 48 is located in the center of the first processing unit 4.
81 has been established. The wafer support mechanism 48 will not be described in detail, but it has wafer support bins that support wafers at three or four points, and the wafer support bins can be moved up and down. Further, 49 indicates an exhaust unit.

The operation will be explained below.

Each processing unit 4゜5.6 connected to the transfer unit 1 performs desired processing required for the wafer processing apparatus, for example,
A material that can be subjected to treatments such as dry etching, CVD, and PVD (physical vapor deposition) is selected in advance.

Each vacuum gate valve 7, 8, 9, 10.11 is closed, each processing unit 4, 5.6 is brought into a vacuum atmosphere by an exhaust unit 49, and the transport unit 1 is also subjected to an exhaust gas (not shown).
A vacuum atmosphere is created by the air supply unit.

In preparation for operating the wafer processing apparatus, a wafer cartridge 31 loaded with unprocessed wafers 23 is loaded into the load unit 2, and the unload unit 3
An empty wafer car I-ridge 31 is loaded into the wafer car. Load unit 2. The unload unit 3 is hermetically sealed, and the inside is evacuated by an exhaust/air supply unit (not shown).

When the inside becomes vacuum, the vacuum gate valves 1 and 8 are opened.

While the loading unit 2 and unloading unit 3 are being evacuated, the attitude of the wafer cartridge 31 is changed from the state shown in FIG. 3 to the state shown in FIG. 4 by rotating the shaft 35 by a necessary means. This is because the wafer 23 is transported so that the wafer 23 does not fall out of the wafer cartridge 31, with the wafer insertion port facing upward, but the direction in which the wafer 23 is handled in the wafer processing equipment is horizontal. It depends.

The rotary seat 19 is rotated and positioned so that the direction of movement of the great arm 22 of the first handling unit 13 moves forward and backward relative to the load unit 2. Further, the lifting mechanism 33 is arranged such that the vertical position of the plate arm 22 is aligned with the top wafer 23 so that the top wafer 23 can be taken out at a desired position, for example, the top wafer 23.
The motor 44 is driven to position the wafer cartridge 31 so that it is between the wafer cartridge 31 and the wafer in the tier.

Next, the first arm 20, the second arm 21, and the plate arm 22 cooperate to insert the plate arm 22 into the wafer cartridge 31. When the plate arm 22 is inserted, the wafer cartridge 31 is slightly lowered by the lifting mechanism 33 so that the uppermost wafer 23 is placed on the plate arm 22.

First arm 20, second arm 21, plate arm 22
The nine-turn seat 19, which moves the plate arm 22 backward and pulls out the wafer 23 from the cartridge 31, is rotated 90'' so that the plate arm 22 moves forward and backward toward the storage stage 15.

The elevating and lowering drive mechanism 25 of the storage stage 15 positions the storage cassette 24 in the vertical direction so that the wafer 23 is inserted into a predetermined stage of the storage cassette 24, for example, the top stage.

After the first handling unit 13 inserts the wafer 23 into the uppermost stage of the storage cassette 24, the lifting drive mechanism 25 slightly raises the storage cassette 25, and the wafer 23
is held in the storage cassette 25.

The plate arm 22 of the first handling unit 13 is moved back.

Plate arm 22° of second handling unit 14
is inserted into the storage cassette 24, and in this state, the storage cassette 24 is slightly lowered by the elevating drive mechanism 25, and the wafer 23 is transferred to the plate arm 22'.

The second handling unit 14 has a plate arm 22°
is retracted to a position where the center of the wafer 23 coincides with the center of the alignment unit 17.

In this position, the optical sensor unit 16 is connected to the wafer 23.
The peripheral edge of the light emitting/receiving element 2 can be detected.
When the peripheral edge detection results of 6a, 26b, 26c, and 26d are the same, it is determined that the center of the wafer 23 and the center of the alignment unit 17 match, and the horizontal alignment of the wafer 23 is completed. - If the detection results of the light receiving elements are not in the same state, horizontal alignment is performed by horizontally moving the great arm 22°.

After alignment in the horizontal direction, alignment in the rotational direction is performed by raising the wafer placement plate 29, rotating the wafer 23 on the wafer placement plate 29, and detecting the notch 23a of the wafer 23 with the light emitting/receiving element 27. For example, if the rotation angle at which the path of the light emitting/receiving element 27 is not blocked by the wafer 23 is determined, the center position of the notch 23a, that is, the position in the rotational direction of the wafer 23 can be detected, and alignment can be performed. . Due to the function of this alignment unit 17, the wafer alignment function in other units can be omitted.

When the alignment of the wafer 23 is completed, the wafer 23 is received again by the plate arm 22'.

Assuming that the wafer 23 is processed in the order of the first processing unit 4, second processing unit 5, and third processing unit 6, the interior 4 of the first processing unit 4 is evacuated, the vacuum gate valve 9 is opened, and the The two-hand unit 14 moves the wafer 23 onto the wafer support mechanism 48, and the wafer support mechanism 48 raises wafer support pins (not shown) to hold the wafer 23.

The second handling unit 14 has a plate arm 22°
After retracting the wafer, the vacuum gate valve 9 is closed, and the exhaust unit 49 and a gas supply unit (not shown) create an atmosphere necessary for processing inside the first processing unit 4, and predetermined wafer processing is performed.

When the wafer processing in the first processing unit 4 is completed, the first
The interiors of the processing unit 4 and the second processing unit 5 are evacuated, the vacuum gate valves 9, 10 are opened, and the second handling unit 14 cooperates with the wafer support mechanisms 48, 48 of the first and second processing units. , the wafer 23 is moved from the first processing unit 4 to the second processing unit 5.

The vacuum gate valve 10 of the second processing unit 5 is closed, and the inside of the second processing unit 4 is made into an atmosphere necessary for processing by the exhaust unit 49 and a gas supply unit (not shown), and a predetermined wafer processing is performed.

In the vacant first processing unit, the wafer 23 is taken out from the load unit 2 in the same manner as described above, and the wafer 23 is placed in the first processing unit.
Charge to processing unit 4.

When the wafer processing is completed in the second processing unit 5, the wafer 23 is moved to the third processing unit 6 in the same manner as the wafer 23 was moved from the first processing unit 4 to the second processing unit 5.

When the wafer processing in the third processing unit 6 is completed, the processed wafer 23 is taken out by the second handling unit 14 and stored in the storage cassette 24 of the storage stage 15. In order to avoid interference with the unprocessed wafer 23, this storage position is set, for example, to the third stage. Further, the processed wafer 23 is taken out from the storage stage 15 by the first handling unit 13 and stored in the wafer cartridge 31 in cooperation with the lifting mechanism 33 of the unloading unit 3.

As described above, the unprocessed wafer 23 is taken out from the load unit 2 and the first handling unit 13,
They are sequentially supplied, and each time each process is completed, they are sequentially sent to the next process by the second handling unit 14, and those that have been processed are stored in the unload unit 3.

These movements of wafers between each unit are performed via the transport unit 1, and moreover, are performed in vacuum.

In addition, if alignment is required again when moving from one process to the next, the alignment unit 17
, or may be returned from one process to the previous process. In this case, it may be returned directly, or if there are wafers remaining in the processing unit during preprocessing, the wafers may be temporarily relayed to the storage stage 15. In this case, it is convenient to set the storage location to the second stage of the storage cassette 24 because it will not interfere with unprocessed wafers, processed wafers, etc.

In addition, in the above embodiment, the number of wafer storage stages of the storage cassette was set to three, but it is of course possible to set the number of wafer storage stages to 5.2 stages, four stages or more. The loss time caused by the difference in handling timing caused by the processing time etc. can be absorbed, increasing efficiency.

Furthermore, the movement path of the wafer can be determined appropriately considering efficiency and processing procedures, and there is no need to fix the functions of the loading unit and unloading unit. Furthermore, if this device is installed in the middle of the production line, it will process the wafers flowing along the line, so the load unit, unit, and unload unit with the above-mentioned configuration will be It will no longer be necessary.

Further, in the above embodiment, three sets of processing units are provided, but two sets may be used, or the shape of the portion of the transport unit where the processing units are provided is pentagonal or hexagonal, and the number of processing units is 4M or 5 sets. Furthermore, three or more sets of handling units may be provided in a straight line, a storage stage may be provided between each handling unit, and various units may be added to correspond to the added handling units.

Furthermore, if a lifting function is added to the handling unit, the loading unit, unloading unit, storage stage, and wafer support mechanism can be lifted and lowered. Ovals can be omitted.

It goes without saying that various changes can be made without departing from the gist of the invention.

[Effects of the Invention] As described above, the present invention exhibits the following excellent effects.

(1) Since the processing method is a single wafer method, it is possible to cope with larger wafers, and it is possible to perform high-quality processing without variations in quality.

(11) High throughput can be obtained because the processing is performed for a number of times.

Since wafers are always moved in a vacuum, it is possible to prevent contamination between each process and the adhesion of dust, resulting in higher quality and a significant reduction in the incidence of defective products.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing one embodiment of the present invention, and Fig. 2 is a plan view showing an embodiment of the present invention.
The A-A arrow view in the figure, Figures 3 and 4 are load units,
FIG. 5 is an explanatory diagram showing the lifting and lowering mechanism of the loading unit and unloading unit; FIG. 6 is a perspective view of the handling unit; FIG.
The figure is a perspective view of a wafer. 1 is a transport unit, 2 is a load unit, 3 is an unload unit, 4 is a first processing unit, 5 is a second processing unit, 6 is a third processing unit, 7, 8.9.10.11
is a vacuum gate valve, 13 is a first handling unit, 1
4 is a second handling unit, 15 is a storage stage,
23 indicates a wafer.

Claims (1)

[Claims] 1) A transfer unit with an airtight interior, a plurality of handling units provided therein, and a storage stage for temporarily storing wafers between the handling units is made to correspond to the handling unit, and a wafer processing unit and a load are provided. A wafer processing apparatus characterized in that necessary units configured to be airtight inside are connected via a vacuum gate valve.