JPH01157547A - Semiconductor wafer processing apparatus - Google Patents

Abstract

PURPOSE:To make an accommodation space during a nonuse period small, to expand a transferable area of an object to be transferred, to enhance operating performance, to make this apparatus lightweight and small-sized and to make an amount of dust particles to be generated from a mechanism during a driving operation extremely little by a method wherein a semiconductor wafer is carried in and out by using an arm of a parallel link mechanism which is equipped with two or more joints and where a part between the joints is constituted by a parallel link. CONSTITUTION:A multiple joint arm of a handling mechanism 6 is constituted by a three-stage parallel link mechanism. A first-stage parallel link mechanism is constituted by first - third links 15, 16, 17 and a base member 18. A second- stage parallel link mechanism is installed in such a way that it is overlapped with the first-stage parallel link mechanism. That is to say, the second-stage parallel link mechanism is constituted by third - sixth links 17, 25, 26, 27. A third-stage parallel link mechanism is installed in such a way that it is overlapped with the second-stage parallel mechanism. The third-stage parallel link mechanism is constituted by the sixth link 27, a seventh link 33, an eighth link 34 and a holding member 14.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a semiconductor wafer processing apparatus.

(Prior art) In the process of manufacturing semiconductor devices such as ICs or LSIs, semiconductor wafers are handled in a clean room to prevent the surface on which ultra-fine patterns are formed from being contaminated by dust or other contamination. . A belt conveyor type or mechanical hand type conveying device is used as a means for conveying semiconductor wafers within a clean room. Particularly, in important processing such as etching processing equipment and ion implantation processing equipment, special handling mechanisms are used to move semiconductor wafers into and out of the vacuum processing chamber one by one. A handling mechanism dedicated to single-wafer processing is desired to have the following performance in order to shorten vacuum processing time and meet the demands for maintaining ultra-cleanliness.

(1) Occupies a small space when not in use, and
The transport distance during use is large ■ The amount of dust generated during use is small Recently, various handling mechanisms that meet the above performance have been developed, and handling mechanisms that are compact and generate less dust have been put into practical use. has been done.

Utility Model Publication No. 60-61191, Japanese Patent Application Publication No. 60-1837
Handling mechanisms for semiconductor wafers are disclosed in Japanese Patent Application Laid-open No. 36 and Japanese Patent Application Laid-Open No. 160949/1983, respectively.

These handling mechanisms utilize a pantograph as a transport mechanism.

Further, the above-mentioned handling mechanism is further miniaturized in Japanese Patent Application Laid-open No. 61-90903 and Japanese Patent Application Laid-open No. 61-873.
51 and Japanese Patent Application Laid-Open No. 61-90887, respectively.

(Problem to be Solved by the Invention) However, in semiconductor wafer processing equipment using a conventional handling mechanism, in order to reduce the storage space when not in use, the arm length of the pantograph is shortened and the number of joints is reduced. If it is reduced, the area in which objects can be transported is limited to a narrow range. On the other hand, if the arm length of the pantograph is lengthened and the number of joints is increased in order to expand the transportable area of objects to be transported, the storage space of the device when not in use becomes larger.

In recent years, as the development of VLSI technology with a density of 4M and 16M progresses, single-wafer processing is required. In order to improve throughput in this single wafer processing apparatus, it is a common technique to use a load lock mechanism. What is required in realizing this load lock mechanism is a transport mechanism that does not generate dust. The key to solving this problem is how to transport increasingly large wafers in a limited space.

Incidentally, a chamber for accommodating a handling mechanism and a vacuum processing chamber for processing semiconductor wafers are separated by a gate valve, and communicate with each other when the gate valve is opened. Therefore, there is a drawback that it takes a long time to bring the vacuum processing chamber into a vacuum state. Furthermore, in the conventional handling mechanism, a considerable amount of dust is generated from the drive mechanism, and this dust enters the vacuum chamber from the handling mechanism housing chamber, contaminating the vacuum processing chamber. In particular, in clean rooms that handle highly integrated ultra-LSIs, ultra-cleanliness of class 10 or higher is required, which has caused inconveniences in the processing of semiconductor wafers.

The object of the present invention has been made in view of the above-mentioned problems.Firstly, a semiconductor wafer is manufactured using a handling arm mechanism that requires a small storage space when not in use and has a large area for transporting objects to be transported. The purpose of this invention is to provide a processing device.

A second object of the present invention is to provide a semiconductor processing device using a handling device that is excellent in operability, light in weight, small in size, and generates extremely little dust from the mechanism during operation.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a semiconductor wafer processing apparatus for automatically loading and unloading semiconductor wafers into a processing chamber, which has a plurality of joints for loading and unloading the semiconductor wafer, and the joints are parallel to each other. It is characterized by the fact that it is carried out by an arm of a parallel link mechanism composed of links.

(Function) The present invention transports a wafer using a parallel link mechanism in which multiple stages or more of parallel links are rotatably connected.
Even if the wafer transport distance is increased, the wafer can be transported in a small space.

In addition, the members constituting the parallel link mechanism and the drive mechanism can be made by, for example, stainless steel coated with tetrafluoride resin, or by forming a hard alumite film on the surface of a metal containing aluminum and then impregnating it with tetrafluoride resin. By using such materials, the generation of dust, etc. can be minimized, and it can be fully applied to things that require cleanliness, such as vacuum equipment, for example.
This makes it possible to transport semiconductor wafers.

(Example) An example in which the apparatus of the present invention is applied to an etching processing apparatus will be described with reference to the drawings.

First, as shown in FIG. 1, an etching apparatus for etching semiconductor wafers one by one is installed in a clean room. The etching processing equipment consists of a vacuum processing chamber (3
) and this vacuum processing chamber to improve throughput■
It has two preliminary chambers (4, 5) for taking wafers in and out of the vacuum processing chamber (3).

The vacuum processing chamber ■ is equipped with a vacuum device (not shown) and an exposure device (
(not shown). Each preliminary chamber (4, 5) is provided with a handling mechanism (2). The approximate size of the vacuum processing chamber (3) is length [370) mm x width [3703 m x height (200] no.).The approximate size of each preliminary chamber (4, 5) is length (300) mm x Width [300] x height [80'31 TITl.

Further, the vacuum processing chamber (3) and the preliminary chamber (4, 5) communicate with each other through openings (3a, 3b), and gate valves (3a, 3b) are connected to these openings (3a, 3b).
7, 8) are provided. Furthermore, the preliminary chambers (4, 5) communicate with the outside through openings (4a, 5a), and these openings (3a, 3b) are also provided with gate valves (
9, 10) are provided.

The preparatory chambers (4, 5) are constructed to a size that accommodates - wafers (1), and are exposed to the atmosphere each time wafers (1) are transferred to and from the outside, so that the desired Must be evacuated to a vacuum.

Therefore, in order for the evacuation to be completed within the desired period,
1 capacity is required, and the movement area of handling mechanism 0 is limited.

A positioning stage (11) is provided in front of the opening (wafer inlet) (4a) of the preliminary chamber (a), and the wafer (12) is moved to the stage (11) by the robot I-hand (not shown). When placed on the wafer, the stage (11) automatically aligns the wafer (g). The handling mechanism (f) of the preliminary room (a) is
From the above-mentioned positioning stage (11) to the vacuum processing chamber (3
) This is a dedicated loading machine for loading wafers (1) to - On the other hand, the handling mechanism 0 in the preliminary chamber (2) is a dedicated machine for carrying out processed wafers (12) from the vacuum processing chamber (3) to the outside.

Cylindrical base member (13) of each handling mechanism (6)
is installed in the center of the preliminary room (4, 5). The rotation of the base member (13) is connected to a rotating shaft of a stepping motor (not shown) having rotational speed control means, and the rotating shaft of the base member (13) is controlled by the stepping motor.
can be rotated at a desired angle around the base member (13). The distance 2L between the center of the base member (13) and the center of the stage (2) of the vacuum processing chamber (2) is approximately [370]nn+.

The arm of the handling mechanism (c) is composed of a three-stage parallel interlocking mechanism (parallel link mechanism). The maximum extension of the arm when in use is LL 2 L II, and the space occupied by the arm (in the folded state) when not in use is "LXW". However, the length W is [50] mm.

As shown in FIG. 2, a holding member (14) is attached to the tip of the arm of the handling mechanism (c).

Note that the holding member (14) is detachably attached to the arm and can be replaced as appropriate depending on the wafer size.

Next, the multi-joint arm of the handling mechanism and its drive mechanism will be described with reference to FIGS. 2 and 5.

The multi-joint arm of the handling mechanism 0 is composed of a three-stage parallel link mechanism. The first stage parallel link mechanism is composed of first to third links (15, ], 6°]7) and a base member (18).

The large pulley (19) is attached to the shaft (19) on the base member (18).
is fixed concentrically. Also, the first link (15)
The -end of is also fixed to the shaft (19). The second link (16) is parallel to this first link (15).
) is rotatably attached to the shaft (20) on the base member (]8).
) is supported by Also, the third link (17)
is rotatably attached to the first link (15) and the second link (16) via shafts (21, 22). Note that these first to third links (15, 16, 1
7) are provided within the same plane.

Next, a mechanism for driving the multi-joint arm will be explained.

A first small pulley (23) is fixed to the shaft (2]).

Then, the wire (24) is passed between the large pulley (19) and the first small pulley (23), and the rotational force of the shaft (19) is transmitted to the small pulley (23) by the wire (24). It looks like this. Large pulley (19) and small pulley (23)
The diameter is 2:1.

In addition, in this case, the first and second links (]5゜16
) are each 'L/2'' length, and the length of the third link (]7) and the mutual distance of the axes (19, 20) are each 'W'' length. In this way, the base member (18) (large pulley (19)) and the first to third links (15, 16, 17) constitute a first stage parallel link mechanism.

Next, the second stage parallel link mechanism will be explained.

The second stage parallel link mechanism is provided so as to overlap the above-described first stage parallel link mechanism. Fourth link (2
5) one end is fixed to the above-mentioned shaft (21), and one end of the fifth link (26) is rotatably attached to the above-mentioned shaft (22). Further, the sixth link (27) is connected to the shaft (2g
, 29a) through the fourth and fifth links (25°26)
are rotatably connected between the two. The lengths of the fourth and fifth links (25, 26) are each 4L L'', and the length of the sixth link (27) is equal to that of the third link (17).
is equal to II W l'. That is, the third to sixth links (17, 25, 26, 27) constitute a second stage parallel link mechanism. Further, a second small pulley (30) is fixed to the shaft (22), a third small pulley (31) is fixed to the shaft (29a), and a wire (32) is fixed to the shaft (29a).
) is wound around the second and third small pulleys (30, 31). The second and third small pulleys (30, 31) are the same as the first small pulley (23) described above.

Next, the third stage parallel link mechanism will be explained.

The third stage parallel link mechanism is provided so as to overlap the above-mentioned second stage parallel link mechanism. The third stage parallel link mechanism includes a sixth link (27) and a seventh link (33).
), an eighth link (34), and a holding member (14). The seventh link (33) has one end fixed to the third pulley (31) with two screws (29b), and the other end rotated to the holding member (14) by a shaft (35). It is movably mounted.

Further, the eighth link (34) has one end connected to the shaft (28).
The other end is rotatably attached to the sixth link (27) and the holding member (14) via a shaft (36). In this case, the seventh and eighth links (33, 3
4) The length of each is “L/2”, and the axis (
35, 36) have a mutual spacing of "W".

In this case, L'' is approximately equal to the diameter of the wafer being handled. For example, in a handling mechanism for handling [8] inch wafers, 17 L'7 is approximately equal to the diameter of the wafer being handled.
0) The length is un. Moreover, It W j+ is I
The range is preferably 1/4 to 1/2 of t L II.

As shown in FIGS. 3 and 4, the arm of the handling mechanism 0 is folded when not in use, so that it can be stored in a small space. The area occupied by the folded arms is approximately LXW wide. Most of the folded arm is hidden under the wafer holding member, with only a portion of the small pulleys (23, 30, 31) protruding from the holding member (14). Also, the links that make up the arm are arranged to overlap vertically.

The material of each link and pulley constituting the parallel link mechanism and its drive mechanism is a base material of stainless steel or aluminum alloy coated with a tetrafluoride resin (so-called Taflam treatment). When using an aluminum alloy as the base material, a hard alumite film is formed on the surface of the base material before coating with the tetrafluoride resin. In addition, the wire (24,
32) is a stainless steel wire coated with a tetrafluoride resin. Furthermore, titanium alloy may be used as the material for the links, pulleys, and wires. Such a tetrafluoride resin coating material generates a negligible amount of dust during sliding contact.

Next, the case where the wafer is taken in and out of the etching processing chamber by the handling mechanism will be described.

A robot hand (not shown) pulls out only one wafer (2) from the cassette and places it on the stage (11). The placed wafer (2) is aligned to a desired position using a robot hand and a sensor (not shown). In this way, after pre-positioning the wafer ■ on the stage (11), the gate valve (
9) and open the opening (4a) of the carry-in preliminary chamber.

The operation of the drive mechanism of the handling mechanism 0 is computer controlled based on predetermined computer software programming. The base member (18) is rotated to direct the wafer insertion port (14a) of the holding member (14) toward the opening (4a). Next, the stepping motor moves the shaft (
19) at low speed and extend the arm of the handling mechanism (6). The holding member (14) is moved straight toward the wafer (1) on the stage (11), and the wafer (1) is held on the holding member (
14). After confirming that the wafer is being held, the stepping motor is reversed, the arm is retracted, and the holding member (1
4) while holding the wafer (]) in the preliminary chamber (
b). Raise the gate valve (9) and close the opening (4a) of the preliminary chamber. Next, the gas in the preliminary chamber (a) is evacuated by a vacuum pump until the internal pressure of the preliminary chamber (4) becomes approximately equal to the internal pressure of the vacuum processing chamber (3). When the internal pressure of the preliminary chamber (a) reaches a predetermined value, the gate valve (
9) is lowered to connect the preliminary chamber) with the vacuum processing chamber (2). The base member (18) is rotated 90° counterclockwise to direct the holding member (14) toward the vacuum processing chamber (2). Next, the shaft (19) is rotated in the normal direction to extend the arm, and the holding member (
The wafer O) held in the holding member (14) is carried into the vacuum processing chamber ■ from the preliminary chamber (4), and the wafer O) held in the stage (2
)” - Transfer the wafer O). Reverse the shaft (]9) to retract the arm and return the holding member (14) to the preliminary chamber (A).

Raise the gate valve (■) by 1" to shut off the vacuum processing chamber (3) from the preliminary chamber (A). Airtight vacuum processing chamber (
3) Etching the wafer inside.

After the etching process is completed, the gate valve (8) is lowered to allow the unloading preliminary chamber 0, which has been evacuated in advance, and the vacuum processing chamber 2 to communicate with each other. The arm of the second handling mechanism (toward) in the preliminary chamber 0 is extended, and the wafer (, 1) on the stage (1) is held by the holding member (14). Wafer (1
), the shaft (19) is reversed to retract the arm, and the wafer held by the holding member (14) is carried from the vacuum processing chamber to the preliminary chamber. The gate valve is raised to shut off the preliminary chamber 0 from the vacuum processing chamber (3). Rotate the base member (13) 90 degrees counterclockwise and hold the holding member (
14) towards the gate valve (1o). Goo 1 - Lower the valve (10) to open the preliminary chamber (2), rotate the shaft (9) in the normal direction to extend the arm, and carry out the wafer (1) from the preliminary chamber (into) to the outside. After carrying out the wafer, retract the arm and return the holding member -15= (14) into the preliminary chamber ■, raise the gate valve (10) to make the preliminary chamber (c) airtight, and exhaust the air in the preliminary chamber 0. do.

As a result, the preliminary chamber (c) becomes ready to receive the next wafer.

Next, the reason why the holding member (14) at the tip of the arm moves straight when the arm of the handling mechanism (1) is extended or contracted will be explained.

This handling mechanism (arm 0) is composed of three stages of parallel link mechanisms.The arms of the first stage parallel link mechanism (first and second links 1.5.16), Parallel linkage arm (fourth and fifth link 25
．． 26) and the length ratio is set to 1:2. Also,
The ratio of the diameters of the first to third small pulleys (23, 30° 31) and the large pulley (19) is also set to 1:2.

Therefore, when the angular displacement of the first link directly driven by the shaft (19) is 1126'', the angular displacement of the fourth link (15) indirectly driven via the small pulley is Therefore, the displacement amount of the tip of the first link (15) is (2δXi/2L), and the displacement amount of the tip of the first link (15) is (2δXi/2L),
Since the amount of displacement of the tip of 5) is (δ×L), the two cancel each other out and the locus of the tip of the arm draws a straight line.

Note that the arm may be a combination of parallel link mechanisms of four stages, one stage, or two or more stages.

According to the etching processing apparatus of the first embodiment, the apparatus can be stored in a space of (LXLXH) when not in use, and the maximum conveyance distance can be set to 2L. for example,
[8] In the handling mechanism of a processing device for inch-diameter wafers, the storage space for this mechanism is (310) mn
X [310) mm X (80) ytn, the maximum transport distance is l:370)mn. Therefore, the volume of the preliminary chamber for loading and unloading wafers can be reduced.
Preparation time before vacuum processing can be significantly shortened.

Further, according to the above embodiment, since each link, pulley, and wire are coated with a tetrafluoride resin, the amount of dust generated due to sliding contact between the members is extremely small. Also, the wire moves with the pulley without slipping against it. Therefore, the intrusion of dust from the preparatory chamber into the vacuum processing chamber is extremely small, and it is possible to maintain a high level of ultra-cleanliness within the vacuum processing chamber.

Further, according to the above embodiment, since various operations of the handling mechanism can be controlled using computer software programming, wafers can be transported unmanned.

In the above embodiment, a case was explained in which a rewafer is taken in and out of a vacuum processing chamber of an etching apparatus by a handling mechanism, but the present invention is not limited to this, and other semiconductor wafers and liquid crystal substrates (LCDs) can be processed in various ways. It also allows access to and from equipment and inspection equipment.

According to the present invention, it is possible to provide a semiconductor wafer processing apparatus that is lightweight, small, and compact, and is capable of obtaining a long transport distance. In particular, since the space occupied by the apparatus when not in use can be made much smaller than the conventional pantograph-type handling mechanism, it is ideal for transporting semiconductor wafers in etching apparatuses that require vacuum processing. For example, when the arm is configured with a three-stage parallel link mechanism, the space occupied by the device in the stored state is reduced by approximately [35]%.

Further, according to the semiconductor wafer processing apparatus of the present invention, the amount of dust generated from the mechanism during operation is extremely small, and it can be used in processing equipment or inspection equipment that needs to maintain ultra-cleanliness, such as ion implantation equipment or probing machines. Ideal for single-wafer processing of semiconductor wafers.

In the above embodiment, an example was explained in which the present invention was applied to an etching device, but it goes without saying that it can be applied to any semiconductor wafer processing device such as an ashing device, an ion implantation device, a sputtering device, etc. be.

〔Effect of the invention〕

As explained above, according to the present invention, by transporting a semiconductor wafer using a parallel link mechanism in which multiple stages of parallel links are rotatably connected, long-distance transport can be achieved with a compact configuration, and the wafer can be transported easily. suitable.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the transport process for explaining the application of the present invention apparatus to an etching processing apparatus, FIG. 2 is a mechanism explanatory diagram for explaining the extended state of the semiconductor wafer transport mechanism of FIG. 1, and FIG. 3 and 4 are mechanism explanatory diagrams for explaining the shortened state of the semiconductor wafer transfer mechanism shown in FIG. 1, and FIG. 5 is a principle explanatory diagram for explaining the operation of the parallel ring mechanism shown in FIG. 2. be. 1... Wafer 2... Stage (mounting table) 3... Vacuum processing chamber 4, 5... Preliminary chamber 6... Handling mechanism 7, 8, 8, 10...
Gate valve 11...Stage 14...
- Holding member 15...first link 16...
Second link 17...Third link Patent applicant Tokyo Electron Ltd. -20= Figure 4;

Claims (2)

[Claims] (1) In a semiconductor wafer processing apparatus that automatically carries semiconductor wafers into and out of a processing chamber, an arm of a parallel link mechanism having multiple stages of joints and configured with parallel links between the joints is used to carry in and out the semiconductor wafers. A semiconductor wafer processing apparatus characterized in that processing is performed by: (2) A semiconductor wafer processing apparatus according to claim 1, wherein each link member of the parallel link mechanism has a surface treated with a tetrafluoride resin.