JP2002517088A - Batch type end effector for semiconductor wafer handling - Google Patents

Abstract

(57) Abstract: A wafer robot including a first end effector and a second end effector, each having one or more wafer holders. A robot arm assembly moves first and second end effectors so as to perform separate operations. A wafer carrier may be loaded or unloaded with one or more operations of a first end effector and one or more operations of a second end effector. The wafer robot may include a vacuum system for vacuum-sucking a wafer on a wafer holder. The end effector may further include a vacuum sensor for detecting the presence or absence of a wafer on each wafer holder.

Description

DETAILED DESCRIPTION OF THE INVENTION

FIELD OF THE INVENTION The present invention relates to an apparatus for handling semiconductor wafers during the manufacture of semiconductor devices, and in particular, for batch transfer of semiconductor wafers to or from wafer carriers, load locks and the like in processing systems. For a batch type end effector.

BACKGROUND OF THE INVENTION Equipment related to semiconductor wafer manufacturing typically includes a number of wafer processing systems located in a clean room. The processing system can include an implanter, an anneal device, a diffusion furnace, a sputter deposition system, an etching system, and the like. Semiconductor wafers are transported from system to system in order to perform processing according to predetermined procedures. Wafers have typically been transported in open containers, such as cassettes, either manually or using various transport systems. A few wafer manufacturers use standard mechanical interface (SMIF) wafers up to 200 mm in diameter.
(Industrial standard of SEMI (Semiconductor Equipment Manufacturers International)) The container was transported by a closed carrier called a box. These carriers typically contain open wafer cassettes accessed through ports or doors on the bottom of the SMIF box. The purpose of the SMIF box is to isolate the wafer from particulate and gas contamination, and to reduce the cost of clean room air filters.

There are many obvious trends in the semiconductor wafer manufacturing industry. Larger wafer (300m diameter)
m), and the device geometry has become smaller. 2 for finished wafer
Worth $ 50,000. For this reason, extremely high handling is required for wafer handling so as not to cause even minute scratches. Further, as the geometry of semiconductor devices is minimized, the accepted particulate contamination standards become more stringent. In recent years, particulate contamination standards have been reduced by as much as two orders of magnitude due to the miniaturization of device geometries. One approach that has been taken to meet particulate contamination standards is the front opening unified pod (FOUP).
d pod) is the storage and transport of wafers in sealed wafer carriers known as d pods. Wafer pods typically store up to 25 wafers and have doors that are opened to access the wafers.

[0004] Since very high handling is required for wafer handling and very high strictness is required for particulate contamination standards, automatic wafer handling and transport is required. Typically, a wafer is removed from a wafer carrier in a processing system and transported to a load lock or other input port of the processing system. Upon completion of processing, the wafer is removed from the system through the same load lock or another load lock and returned to the wafer carrier. Transport between the wafer carrier and the processing system is typically performed by a wafer robot.

[0005] The basic components of a wafer robot include an end effector that holds one or more wafers, and a robot arm drive mechanism that moves the robot arm according to signals from a controller. An example of the operation of the robot arm is
Removing one or more wafers from a wafer carrier and transporting the wafers to a load lock of a processing system. This basic operation typically involves various tasks such as inserting a wafer holder into a wafer carrier between wafers, lifting a wafer from a wafer support in the wafer carrier, and withdrawing the wafer holder from the wafer carrier. Operation of various components. Regarding wafer robots, for example, US Pat. No. 5,607,276 (Muka et al., Issued Mar. 4, 1997), US Pat. No. 5,609,459 (Muka, issued Mar. 11, 1997), and US Pat. No. 5,664,925 (1997) Published on September 9, Muk
a) et al., US Patent No. 5,613,821 (Muka et al., issued March 25, 1997).

[0006] A wafer robot and its associated end effector require a number of things. Loading and unloading of wafer carriers must be completed as quickly as possible to facilitate high throughput and reduce manufacturing costs. A batch type end effector capable of transporting a large number of wafers simultaneously must be more efficient than a single end effector. However, a batch end effector designed for use with one size wafer carrier cannot be used with another size wafer carrier. Further, prior art end effectors maintain the wafer in a fixed position on the wafer holder by gravity and frictional resistance.
Therefore, in order to securely place the wafer at the fixed position of the wafer holder, it is necessary to limit the moving speed. Also, the prior art end effectors did not have the ability to detect the presence or absence of a wafer on each wafer holder. Therefore, a wafer which should not exist was not detected.

[0007] It is therefore desirable to provide a wafer robot and an end effector for handling semiconductor wafers that overcome one or more of the above disadvantages and disadvantages.

[0008] According to a first aspect of the present invention, there is provided a wafer robot. The wafer robot includes a batch type end effector, a vacuum pump, and an arm for moving the batch type end effector. Batch end effectors consist of a support block, a vacuum manifold, and two or more wafer holders attached to the support block. Each of the wafer holders includes a wafer support having a suction port, and a suction path connected between the suction port and the vacuum manifold. The batch type end effector further comprises vacuum sensors respectively connected to each of the suction paths for detecting presence / absence of a wafer in each of the wafer holders.

[0009] The vacuum manifold is preferably located adjacent to the wafer holder. In one embodiment, the vacuum manifold is located on a support block.

[0010] Preferably, each of the wafer holders includes an element defining a restriction in the suction path to suppress gas flow from the suction port to the vacuum manifold. The vacuum sensor is connected to a suction path between the suction port and the restriction.

[0011] Each suction port of the wafer support is preferably arranged to attract around the wafer. In an embodiment of the present invention, the suction port is arranged to attract a forbidden area of the wafer.

According to another aspect of the present invention, a wafer robot is provided. The wafer robot moves a first end effector having a first number of wafer holders, a second end effector having a second number of wafer holders, and the first and second end effectors to perform separate operations. An arm assembly for loading and unloading a wafer carrier with one or more operations of a first end effector and one or more operations of a second end effector. And a controller for independently controlling the operation of the end effector.

[0013] In a first embodiment, an arm assembly comprises a first arm for moving a first end effector and a second arm for moving a second end effector. . In a second embodiment, the arm assembly comprises one arm for moving the first and second end effectors.

[0014] Preferably, the number of wafer holders of the first and second end effectors is selected to allow loading and unloading of at least two different sized wafer carriers with a relatively small number of operations. In one embodiment, the first end effector comprises six wafer holders and the second end effector comprises one wafer holder. In this embodiment, the first and second end effectors can load and unload a wafer carrier having a capacity of 25 wafers in 5 operations and have a capacity of 13 wafers in 3 operations. Load and unload wafer carriers.

DETAILED DESCRIPTION For a better understanding of the present invention, reference is made to the accompanying drawings. FIG. 1 schematically shows a wafer robot according to an embodiment of the present invention. The wafer robot 10 includes a first arm 14
And a second end effector 20 supported by a second arm 22. The arms 14 and 22 are supported by a robot body 24. The end effector 12 is moved by an arm 14, and the end effector 20 is moved by an arm 22. The movement may include, for example, raising and lowering each of the end effectors, and translating each of the end effectors horizontally. The arms 14 and 22 are controlled by signals from the robot controller 30.

The end effector 12 includes a support block and one or more wafer holders 42. The wafer holder 42 is mounted on the support block 40 and is spaced so that it can access the wafer of the wafer carrier. The wafer holder 42 has a thin and flat shape, and can be moved into a space between the wafers of the wafer carrier. The arm 14 is a support block 40
Attached to. The end effector 20 includes a support block 50 and a wafer holder 52 attached to the support block 50. The arm 22 is attached to the support block 50.

In the example of FIG. 1, the end effector 12 includes six wafer holders 42, and the end effector 20 includes one wafer holder 52. Here, it is understood that within the scope of the present invention, each end effector may have a different number of wafer holders. Typically, one end effector includes one or more wafer holders and the other end effector includes two or more wafer holders.

An embodiment of the wafer robot according to the present invention is shown in FIGS. 1 to 6 are denoted by the same reference numerals. As shown in FIG.
Are supported by the robot body 24. Arm 14 includes an upper arm 90 connected to body 24 at shoulder 74 and a forearm 76 connected to upper arm 72 at elbow 78. The support block 40 is connected to the forearm 76 by a suitable bracket 80 and wrist 82. Arm 22 includes an upper arm 90 connected to body 24 at shoulder 92 and a forearm 94 connected to upper arm 90 at elbow 96. Support block 5 of end effector 20
The 0 is connected to the forearm 94 at the wrist 98.

In operation, each of the arms 14, 22 can rotate with respect to a respective shoulder 74, 92 and change height with respect to the body 24. The forearms 76, 94 are rotatable relative to the upper arms 72, 90 with respect to the elbows 78, 96, respectively. The support blocks 40, 50 respectively have forearms 76, 9 with respect to their respective wrists 82, 98.
Can rotate relatively to 4. In the example of FIGS. 2 to 5, the end effectors 12, 20 are:
Typically, during loading and unloading of a wafer carrier or processing system wafer, it is moved radially with respect to a central axis 110 of
0 and rotated from one station to another (eg,
(From wafer carrier to processing system). Here, it is understood that various configurations of the robotic arm can be used within the scope of the present invention. For example, one arm may be used for supporting and moving the end effectors 12, 20, and the support blocks 40, 50 may be connected to the arms via separate wrists.

FIGS. 4 and 5 show details of the end effectors 12 and 20. Wafer holder 42,
Each of the 52 has a thin cross-section as shown in FIG. 4 and comprises a substantially U-shaped rigid metal support element 120 as shown in FIG. In particular, each wafer holder 42
Includes a base 130 and arms 132, 134 projecting from the base 130 to form a U-shape. Each wafer holder is provided with a wafer receiving surface 140 having one or more suction ports.

In the examples of FIGS. 4 and 5, each wafer holder 42 includes a suction port 142 provided in the base 130, a suction port 144 provided near an end of the arm 132, and the arm 13
4 includes a suction port 146 provided near the end. Each of the suction ports is provided with a suction path 150.
To the vacuum manifold 160. Preferably, the vacuum manifold 160 is located adjacent to the wafer holder 42. In the preferred embodiment, vacuum manifold 160 is located on support block 40. As described below, the vacuum manifold 160 is connected to a vacuum pump. Therefore, the air sucked through the suction port sucks each wafer in vacuum. As shown in FIG. 4, the suction path 150 is formed like a recess on the back side of each wafer holder. This recess is covered with a thin plate 164 and seals off each suction channel 150. Suction path 150
May be connected to the vacuum manifold 160 by, for example, flexible tubing.

As will be described later, each of the suction paths 150 can be connected to a vacuum sensor for detecting the presence or absence of a wafer on the wafer holder 42. One vacuum sensor is provided for each wafer holder. The vacuum sensor can be attached to the support block 40. The vacuum sensors 170, 172 are shown in FIG. As shown, the suction path 15
0 may be connected to the vacuum sensor 170 by a flexible tube 176.

In a preferred embodiment, the suction ports 142, 144, 146 are located on the wafer holder 42 so as to attract the semiconductor wafer near its outer periphery. In particular, suction port 1
42, 144, 146 may attract the wafer in a forbidden area around the wafer where no devices will be fabricated. This forbidden region is the outer peripheral portion of the wafer, usually 3 to 5 mm wide, which is not productive due to the process edge effect. Therefore, the suction ports 142, 144
, 146 are formed in an arc shape. The wafer holder 42 is provided with wafer retainers 180, 182, 184 projecting upward to prevent the wafer 44 from moving in the horizontal direction with respect to the wafer holder 42 due to insufficient pressure reduction or the like.

The above-described wafer robot shown in FIGS. 1 to 6 is advantageous for loading and unloading wafer carriers of different sizes. The configuration in which the end effector 12 has six wafer holders and the end effector 20 has one wafer holder is particularly suitable for loading and unloading of two types of standardized wafer carriers used in the semiconductor manufacturing industry. There are advantages. In particular, one standardized wafer carrier is configured to hold 25 wafers, and the other standardized wafer carrier is configured to hold 13 wafers. The number of wafer holders in the end effector is selected to efficiently access both standardized wafer carriers. A wafer carrier capable of processing 25 wafers can be accessed with four operations of the end effector 12 and one operation of the end effector 20 (6 + 6 + 6 + 6 + 1 = 25). A wafer carrier capable of processing thirteen wafers can be accessed with two operations of the end effector 12 and one operation of the end effector 20 (6 + 6 + 1 = 13). Here, it can be understood that the number of wafer holders of each end effector depends on the size of the wafer carrier used. Wafer robots have two or more end effectors, each with one or more wafer holders
May be provided.

FIG. 6 shows a block diagram of a vacuum suction and detection system of the wafer robot. A vacuum pump 200 is connected to the vacuum manifold 160. The vacuum pump 200 sucks air from the vacuum manifold 160, thereby sucking air through each of the suction ports (for example, the suction ports 142) of the wafer holder 42. The vacuum system vacuum-adsorbs the wafers 44 arranged in the respective wafer holders. Flow restrictor 20
2 are connected to each of the suction paths 150 between the suction port and the vacuum manifold 160. One of the vacuum sensors 170, 172, etc. is connected to each of the suction paths 150 between the respective flow restrictor and the suction port. The vacuum sensor detects the pressure of each suction path, and thereby detects the presence or absence of a wafer on the wafer holder.
Here, it can be understood that the pressure of the suction path 150 is lower when there is a wafer on the wafer holder than when there is no wafer on the wafer holder. The vacuum sensor includes, for example, a diaphragm, and converts the movement of the diaphragm into an electric signal. Vacuum sensors are available to those skilled in the art and are commercially available. Vacuum sensor 170, 1
Outputs such as 72 are provided to a controller 210 having a predetermined routine for responding to the presence or absence of a wafer on each wafer holder. A vacuum sensor cable 212 (FIG. 3) connects the vacuum sensors 170, 172, etc. to the controller 210 through the arm 14. The vacuum sensor cable 212 may also include a conduit that interconnects the vacuum manifold 160 and the vacuum pump 200.

The flow restrictor 202 suppresses airflow between the suction port of the wafer holder and the vacuum manifold 160, effectively isolates each suction path of the wafer holder from the vacuum manifold 160, and performs independent wafer detection. enable. Here, it can be understood that when there is no flow restrictor, the pressure in one suction path is affected by the pressure in the other suction path, and an instruction for the presence or absence of a wafer may be erroneously made. The flow restrictor 202 includes vacuum sensors 170, 17
2. It may have a relatively small orifice that is selected to ensure independent wafer detection, such as by. The flow restrictor may have a fixed or variable orifice.
In one embodiment, the flow restrictor 202 is incorporated as a relatively small diameter flexible tube cross section.

While the preferred embodiment of the invention has been illustrated, various modifications and changes may be made without departing from the scope of the invention as defined in the claims. It will be clear to those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a wafer robot according to an embodiment of the present invention.

FIG. 2 is a side view of a wafer robot according to the present invention.

FIG. 3 is a rear view of the wafer robot.

FIG. 4 is a partial side view of the batch type end effector.

FIG. 5 is a plan view of a batch type end effector.

FIG. 6 is a block diagram of a vacuum suction and detection system used for an end effector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Wafer robot 12 ... 1st end effector 14 ... 1st arm 20 ... 2nd end effector 22 ... 2nd arm 24 ... Robot main body 40, 50. ..Support blocks 42, 52 ... Wafer holder 44 ... Semiconductor wafer 72, 90 ... Upper arm 74, 92 ... Shoulder 76, 94 ... Forearm 78, 96 ... Elbow 82, 98 ...・ Wrist 110 ・ ・ ・ Center axis 120 ・ ・ ・ Support 130 ・ ・ ・ Base 132, 134 ・ ・ ・ Arm 140 ・ ・ ・ Wafer receiving surface 142, 144, 146 ・ ・ ・ Suction port 150 ・ ・ ・ Suction path 160 ・..Vacuum manifold 164 ・ ・ ・ Plate 170,172 ・ ・ ・ Vacuum sensor 176 ・ ・ ・ Flexible tube 180,182,186 ・ ・ ・ Retainer 200 ・ ・ ・Check pump 202 ... flow restrictor 210 ... controller 212 ... vacuum sensor cable

[Procedural Amendment] Submission of translation of Article 34 Amendment of the Patent Cooperation Treaty

[Submission date] June 8, 2000 (2000.6.8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Claims (19)

[Claims] 1. A wafer robot, comprising: a support block, a vacuum manifold, a suction port attached to the support block, each of which has a suction port and a suction path connected between the suction port and the vacuum manifold. Consisting of a wafer support having 2
Or more wafer holders, a vacuum sensor connected to each of the suction paths, a vacuum sensor for detecting the presence or absence of a wafer on each of the wafer holders, and a vacuum pump connected to the vacuum manifold A wafer robot comprising: an end effector; and an arm connected to the support block and configured to move the batch type end effector. 2. The wafer robot according to claim 1, wherein said vacuum manifold is disposed adjacent to said wafer holder. 3. The vacuum manifold is located on the support block.
The wafer robot according to claim 1. 4. The vacuum sensor of claim 1, wherein said batch end effector further comprises an element defining a restriction in each of said suction passages to suppress gas flow from a respective suction port to said vacuum manifold. 2. The wafer robot according to claim 1, wherein each is connected to the suction path between the suction port and the restriction. 5. The batch end effector further comprising an element defining a restriction in each of the suction passages selected to ensure independent operation of the vacuum sensor. One wafer robot. 6. A means for controlling movement of said arm, said controller receiving signals from each of said vacuum sensors for monitoring the presence or absence of a wafer on a respective wafer support. Consisting of
The wafer robot according to claim 1. 7. The wafer robot according to claim 1, wherein the suction ports of each of the wafer supports are arranged to attract the outer periphery of the wafer. 8. The wafer robot according to claim 1, wherein a suction port of each of said wafer supports is arranged to attract a forbidden area of a wafer located thereon. 9. The U-shaped base and the U-shaped base such that each of the wafer supports has a substantially U-shape and the suction port attracts a forbidden area of a wafer located thereon. 2. The wafer robot of claim 1, wherein the wafer robot is disposed on a side. 10. A wafer robot, comprising: a first end effector having one or more first number of wafer holders; a second end effector having one or more second number of wafer holders. An arm assembly for moving the first and second end effectors to perform separate operations; and one or more operations of the first end effector; and the second end effector A controller for independently controlling the operation of said first and second end effectors for loading or unloading a wafer carrier in one or more operations. 11. The apparatus of claim 11, wherein the arm assembly comprises a first arm for moving the first end effector, and a second arm for moving the second end effector. Item 10. The wafer robot according to Item 10. 12. The wafer robot according to claim 10, wherein said arm assembly comprises one arm for moving said first and second end effectors. 13. The wafer robot of claim 10, wherein the first and second numbers of the wafer holders are selected to load and unload at least two sizes of wafer carriers with a relatively small number of operations. . 14. The first end effector comprises six wafer holders, the second end effector comprises one wafer holder, and the first and second end effectors comprise 25 wafers in five operations. 11. A wafer carrier having a processing capacity of 13 wafers can be loaded and unloaded, and a wafer carrier having a processing capacity of 13 wafers can be loaded and unloaded in three operations.
Wafer robot. 15. The wafer robot according to claim 10, wherein said first and second end effectors include means for vacuum-sucking a wafer to said wafer holder. 16. The wafer robot of claim 15, wherein said first and second end effectors include a vacuum sensor for detecting the presence or absence of a wafer on each of said wafer holders. 17. A wafer robot, comprising: a first end effector having one or more wafer holders, a first end effector coupled to the first end effector for moving the first end effector. A robot arm, a second end effector having one or more wafer holders, a second robot arm coupled to the second end effector for moving the first end effector, the first and the second A robot body for independently supporting the two robot arms,
And a controller for independently controlling the operation of the first and second robot arms. 18. The wafer robot according to claim 17, further comprising a vacuum system for vacuum-sucking a wafer to each of the wafer holders of the first and second end effectors. 19. The wafer robot according to claim 18, wherein each of the wafer holders of the first and second end effectors includes a vacuum sensor for detecting the presence or absence of a wafer.