JP2540524B2 - Wafer support - Google Patents

Description

Description: FIELD OF THE INVENTION This invention relates to an apparatus for manufacturing integrated circuits.

Prior Art and Problems One of the fundamental problems in manufacturing integrated circuits is particulate matter. This problem is compounded by two trends in integrated circuit processing. First, as device dimensions shrink, it becomes necessary to avoid the presence of smaller particles. This makes it increasingly difficult to ensure that the clean room is actually clean. Class 1 for particles larger than 1 micron (having 1 particle per cubic foot)
A clean room can be as bad as class 1,000 or even more if you count particles up to 100Å.

Second, there is an increasing desire to use larger sized integrated circuit patterns. For example, integrated circuit sizes larger than 50,000 square mils are now in use much more than five years ago.

For this reason, particulate matter is not only a very important source of loss in the manufacture of integrated circuits, but its importance will continue to increase very rapidly. Accordingly, it is an object of the present invention to provide a generally applicable method of manufacturing integrated circuits that reduces the effect of particulate contamination on the process.

One of the major sources of particulate matter contamination is human-generated, including particles emitted by the human body as well as particles agitated by operators of equipment moving within semiconductor processing facilities (front ends). To reduce this, a common trend in the industry over the last few years has become to make more use of automated transfer operations. At this time, the technician would, for example, load a cassette of wafers into the machine, then the machine would automatically pass the wafers one at a time from the cassette (to perform the necessary processing steps) and then back into the machine. No one has to touch the wafer.

However, efforts in this direction have revealed the importance of the second important source of particulate matter. This is the particulate matter generated internally by the wafer and / or the transfer mechanism. That is, if the surface of the wafer moves slightly in contact with another hard surface, some particulate matter (of silicon, silicon dioxide or other material) tends to be released.
The density of particulate matter inside a conventional wafer support is typically very high due to the source of such particulate matter. In addition, many conventional wafer transport mechanisms themselves generate significant amounts of particulate matter.

The present invention advantageously solves this problem by providing a wafer support that reduces the generation of particulate matter during shipping in several ways. First, the vacuum support door has an elastic element that gently presses the wafer against the backside of the support box. Thus, when the box door is closed, the wafer is restrained against rattling, which reduces the generation of particulate matter inside. Second, each side of the wafer is supported by a lightly beveled shelf, which results in very little contact between the wafer surface and the shelf surface (line contact). This reduces the generation of particulate matter due to wear on the surface of the wafer.

The present invention not only reduces the generation of particulate matter within the support during transport and storage, but it also transports the wafer face down under high vacuum, which allows particles to be transferred to the surface of the wafer during transport and storage. The transport of particulate matter is also advantageously reduced. No one has addressed this problem in the past.

This wafer support design has been used with the wafer transport mechanism of the present invention, which is described in a separate application,
A complete wafer transportation device with less particulate matter can be obtained.

The current wafer loading mechanism used in the semiconductor industry is mainly composed of three basic types. That is, a belt driven wafer transport device, an air track driven wafer transport device, and an arm driven wafer transport device (using either a vacuum bond or a cage-like hold to hold the bottom or edge of the wafer). . However, all of these types of devices move the wafer face up as it moves in and out of the support, move the wafer support vertically during loading and unloading operations, and range from atmospheric pressure to low vacuum. This typically involves the transfer of the wafer under pressure and unloading the wafer in reverse loading order. Therefore, the conventional method has a number of important drawbacks as described below.

First, wafers that are transported face up tend to trap particles generated by the particle generation mechanism inside the wafer support or inside the wafer loader device.

Second, the vertical movement of the wafer support during the loading and unloading operations results in a large number of particles due to wafer wobbling in the support. There is a risk that these particles will fall directly onto the effective surface of the next wafer, which is mounted face up in the support.

Third, the belt mechanism typically scrapes the bottom of the wafer during loading and unloading operations, again creating a large number of particulate matter by abrasion.

Fourth, air trucking equipment causes a large number of particulate matter to be entrained around it by the flow of air, many of which are deposited on the effective surface of the wafer.

Fifth, the drive mechanism of many loader modules is housed in the same area as the open wafer support,
Very close to the wafer being processed. This is likely to cause a significant amount of pollution.

Sixth, as the wafer is loaded and unloaded, the mass of the support-wafer combination may change, which may affect the reliability and alignment of the wafer support vertical drive. This is especially true when dealing with large wafers (eg 150 mm or more).

Seventh, each processing station typically uses two loading modules, thus gradually loading one cassette and loading wafers from this processed cassette into a second cassette. .

Eighth, the machine must idle while the cassette is being removed, reducing the efficiency of use of the device each time a new cassette of wafers is loaded into or out of each processing station.

The present invention provides an advantageous solution to all the above-mentioned problems and provides significantly improved wafer handling and loading operations with reduced particulate matter.

One important advantage of the present invention is that wafers can be transported, loaded and unloaded without encountering atmospheric pressure or low vacuum conditions. At a pressure of about 10 ^-5 Torr, this is extremely useful because there is no Brownian motion to support particulates larger than about 10 nm, and these particulates fall out of this low pressure atmosphere relatively quickly. Is.

FIG. 2 shows the time required for particles of different sizes to fall 1 meter at atmospheric pressure. Note that at pressures of 10 ⁻⁵ Torr (1E ⁻⁵ Torr) or less, even 10 nm particles fall 1 meter per second and larger particles fall even faster. (Large particles simply fall ballistically due to gravitational acceleration.) Therefore, an atmosphere with a pressure of less than 10 ^-5 Torr will cause particles of 10 nm or larger to be transported only ballistically, causing irregular air flow. It means that it cannot be carried to a significant surface of the wafer due to drift of the flow or Brownian motion.

The relevance of this curve to this invention is that it allows wafers from one process station to another process, including loading and unloading steps, without exposing the wafers to pressures above 10 ^-5 Torr. This is the first time we have provided a method of transportation. That is, from the time the wafer is loaded into the first vacuum processing station (which may be a scrubbing and pump down station) to the time the processing is complete, the process itself (eg, a normal photomechanical station or wet process). The wafer is never exposed to airborne particulate matter unless a higher pressure is required (such as in a process step). This means that the overall likelihood of particulate matter collecting on the wafer is significantly reduced.

The key to this advantage is that the present invention provides a method and apparatus for loading and unloading a vacuum support under high vacuum.

The present invention provides a load lock. This load lock opens the vacuum wafer support under vacuum and removes the wafers from the support in any desired random access sequence, in any order, one wafer at a time, such as in a plasma etch chamber. It includes a device that passes through a port to an adjacent processing chamber. Further, the loadlock of the present invention can close and reseal the wafer support so that the loadlock itself can be at atmospheric pressure and the wafer support can be removed without breaking the vacuum within the wafer support. .

A particular advantage of the preferred embodiment of the present invention is that the mechanical equipment that is preferably used for wafer transfer is extremely compact. That is, the transfer arm is pivotally attached to the arm support, and a gear device or a chain drive device is provided inside the arm support so that the rotation of the arm support is
By allowing the transfer arm to rotate twice as much with respect to the arm support, it can be stationary in place and does not require a gap in one direction greater than the length of the arm support. In either of the two directions, a compact device can be obtained that can be extended to the length of the arm support plus the length of the transfer arm by simple movement of the rotary shaft.

Another advantage of the preferred embodiment of the present invention is that the motor used to extend the transfer arm and change its height is
Both are held inside the exhaust manifold so that particles generated by these moving mechanical elements are
There is no tendency to reach the inside of the load lock chamber where the wafer is exposed.

Another advantage of the present invention is to provide a transfer arm that can handle wafers face down so that contact with the transfer arm causes minimal damage to the area of the apparatus.

Another advantage of the present invention is that the present invention provides a wafer transfer apparatus that can handle wafers with minimal particulate matter generated by handling operations.

Another advantage of the present invention is that the present invention provides a transfer apparatus that can handle wafers without substantially generating particulate matter due to wear because they do not substantially make sliding contact. is there.

Another advantage of the wafer transport mechanism of the present invention is that the controller is simple. That is, the transfer arm that is preferably used has only two degrees of freedom and position alignment is provided so that control of the transfer arm does not require a sensor to detect the position of the arm or the force exerted on the arm. , (By using a step motor or equivalent device) is quite simple.

A related advantage of the wafer transport mechanism of the present invention is that it is a stable mechanical device. That is, the small positioning error does not accumulate and is attenuated and eliminated by the inherent negative feedback performed by using a certain mechanical element. This facilitates the advantage of simple control.

Another advantage of the present invention is that the wafer handling equipment used within the load lock occupies a minimal volume. Since the load lock is small in volume, the vacuum cycle can be performed at high speed without the need for a very expensive large vacuum pump.

A further important consequence of the volumetric efficiency of the wafer transport apparatus of the present invention is that the upper portion of the load lock (which exposes the vulnerable surface of the wafer being transported) has a small surface area. It is desirable to have the surface area within the line-of-sight of the surface of the wafer as small as possible, and it is also desirable to have the surface area very close to the surface of the wafer as small as possible, both within and outside the line-of-sight. The total surface area of the upper portion of the load lock (ie the portion above the exhaust manifold) presents two hazards. First
In addition, all surface areas absorb gas, so that the larger the surface area in the upper chamber, the more difficult it is to draw a high vacuum. Second, and more importantly, all surface areas are capable of retaining adherent particulate matter, which may subsequently undergo mechanical vibrations or shocks even under high vacuum. May be extruded like a ballistic jump onto the surface of the wafer. Therefore, the volumetric efficiency of the loadlock of the present invention means that the probability of ballistic transport of particulate matter to the surface of the wafer is reduced.

Further, another embodiment described in this continuing application is another advantage in that the wafer itself is within the loadlock and does not see any surface exposed to particulate matter when loading the support into the lock. Have. In this embodiment, the wafer support has a vacuum-tight vertically removable cover instead of a vacuum-tight hinged door, so that the support has an upper chamber (main load lock). ), The support body is lowered from under the cover in the lower chamber, while the cover stays in place, covering the opening between the upper chamber and the lower chamber. For this reason, the wafer support body and the wafer in it will never see the dirty ambient atmosphere, nor will they see the surface exposed to the dirty ambient atmosphere.

Another advantage of the compact wafer handling equipment in the loadlock of the present invention is that such equipment does not consume excessive clean room floor space, which is invaluable. is there.

Another advantage of the wafer support described in this application is that it does not accidentally open outside the clean room. A substantial yield problem in conventional clean room processing is that the wafer is inadvertently or inadvertently exposed to particulate matter by opening the wafer support outside the clean room environment. Is. However, with the wafer support of the present invention, this is because the differential pressure of the support on the door keeps the support tightly closed except when the support is in vacuum. It is essentially impossible. This is another reason why the present invention is advantageous in that it allows wafers to be easily transported and stored outside of a clean room environment.

In another group of embodiments of the invention, the process modules (which may optionally have one process station or more than one process station) may have more than one of the invention. Load lock is installed. Therefore, it is possible to reload the wafer loaded in the other load lock while continuing to process the wafer carried in the one load lock. Furthermore, 2
The provision of two transfer mechanisms uses the transfer of the other load lock while calling a technician to fix the mechanical failure when one transfer device in the load lock has a mechanical problem. This means that the production of the processing section can be continued. Such a group of embodiments has the advantage of higher yield.

The present invention provides a method of manufacturing an integrated circuit.
This method provides a plurality of wafers in a vacuum-sealable wafer support box, the wafer support box having a vacuum-sealable cover on its body, the cover being supported within the body. The wafer is detachable from the main body in a direction substantially normal to the plane of the wafer, and has a partial floor having an opening therein and a stage arranged under the opening in close proximity to the floor. The wafer support is placed in a load lock upper chamber that can be sealed in vacuum, the load lock upper chamber is depressurized to a pressure of less than 10 ⁻⁴ Torr, the stage is lowered, and the cover is positioned above the upper chamber. While still supported on a partial floor, the body containing the wafer is allowed to be lowered into the lower chamber and the wafer is kept under vacuum until the desired sequence of processing operations is complete. The desired order , Transfer to one or more selected process stations enclosed in an adjacent vacuum-tight space connected to the lower chamber and then raise the stage to support the wafer support body Recombining with the body cover and achieving a vacuum seal therebetween, venting the upper chamber to the environment, and removing the wafer support from the upper chamber.

The present invention has a wafer support body that includes a support body including a crosspiece that is tapered so as to support a flat disk with substantially line contact, not surface contact, and the support body is continuous with a base portion. The base includes a vacuum seal surrounding the side support, and further has a cover mated to the vacuum seal of the wafer support body, wherein the cover, the vacuum seal and the body are vacuumed. Limiting the tight envelope, the cover provides a wafer support that is removable from the body in a direction generally normal to the plane of the vacuum seal.

According to the present invention, there is provided a main body including a side wall, and a cover which can be closed together with the main body so as to form a vacuum-tight seal, and each of the side walls has a plurality of slots defining a slot for holding a wafer having a predetermined size. A wafer support is provided having a ledge and at least one face of the ledge of the sidewall is beveled such that it is offset by at least 5 ° from a direction parallel to the plane of the slot.

In the present invention, the main body including the side wall and the cover that can be sealed together with the main body to form a vacuum-tight seal are provided.
Each of the side walls has a plurality of crosspieces that define a slot for holding a wafer of a predetermined size, and at least one surface of the crosspiece of the side wall has at least a direction parallel to the plane of the slot. There is a gradient so that it is offset by 5 °,
Further, there is provided a wafer support having an elastic element on an inner surface thereof, the elastic element fixing the wafer having the predetermined size so as not to move freely.

According to the present invention, a method of transporting an integrated circuit wafer during manufacturing includes vacuuming the wafer in a vacuum-tight support having a body that includes sidewalls and a cover that can be sealed together with the body to create a vacuum-tight seal. And each side wall has a plurality of rails that define a slot for holding a wafer having a predetermined dimension, and at least one surface of the side wall rail has a plane relative to the plane of the slot. The method is such that there is a gradient such that it is offset from the parallel direction by at least 5 °.

According to the present invention, a method of transporting an integrated circuit wafer during manufacturing is such that the wafer is vacuumed in a vacuum-tight support having a body that includes sidewalls and a cover that can be sealed together with the body to form a vacuum-tight seal. The side wall has a plurality of rails that define a slot for holding a wafer having a predetermined size, and at least one surface of the side wall rail is parallel to the plane of the slot. Providing a method for holding a wafer having a predetermined size so that the wafer does not move freely because the support has an elastic element on its inner surface and is inclined by at least 5 ° from the normal direction. To do.

In the present invention, a vacuum-tight support having a step of transporting an integrated circuit wafer during manufacturing, the step of transporting having a body including sidewalls and a cover that can be sealed together with the body to create a vacuum-tight seal. In which the wafer is carried in a vacuum, the sidewall having a plurality of rails each defining a slot for holding a wafer of a predetermined size, the sidewall having at least one surface of the rail having a plurality of rails. There is a gradient of at least 5 ° from the direction parallel to the plane of the slot,
Further, the support has an elastic element on its inner surface, and the elastic element firmly holds the wafer having the predetermined size so that the wafer does not move freely. A method of manufacturing an integrated circuit is provided that includes allowing the wafer to remain in a vacuum state within the wafer support while the support is held closed by the differential pressure.

 The present invention will now be described with reference to the drawings.

Embodiment Next, the configuration and usage of the presently preferred embodiment will be described in detail. However, the idea of the present invention can be applied to a wide range of cases that can be implemented in a very wide variety of cases, and the specific embodiment described here exemplifies a specific method of utilizing the present invention. It should be understood that this is merely a limitation of the scope of the present invention.

FIG. 1 shows one embodiment as a sample of the present invention. In this embodiment, the wafer support in the vacuum load lock chamber 12 is
Shows 10. The wafer support 10 is described in more detail in Section 4.
Also shown in the figure.

Support 10 is shown with its door 14 open. It is preferable to have a vacuum seal 13 where the door 14 mates with the body of the support 10 so that even if the wafer support is carried at below atmospheric pressure for at least several days (preferably at least tens of days) No leaks that would increase pressure above 10 ^-5 Torr.

The wafer support 10 is adapted to mate with a platform 18 (which is only partially shown in FIG. 1, but is shown in more detail in FIG. 4) so that a technician can load the wafer support 10. Support when placed inside lock 12
It is designed so that the position of 10 can be accurately known. In the presently preferred embodiment, the wafer supports 10 have protrusions 16 which engage vertical slots 17 secured to the alignment platform 18 so that the technician can The support can be slid along this slot until it touches, thus ensuring that the position of the support 10 is clearly known. In the presently preferred embodiment, platform 18 is
Two taper pins 21 (one is conical, one is arranged to engage a taper hole 23 on the underside of the wafer support 10).
Although it has a wedge shape, a wide range of other devices can be used to ensure mechanical alignment, as will be apparent to those skilled in the art.

The support 10 preferably has a safety catch 15 which holds the door 14 from opening. However, under normal shipping conditions, this safety catch is not necessary because atmospheric pressure holds the door 14 closed against the internal vacuum of the support. When the support 10 is put inside the load lock 12,
The fixed finger 19 hits the safety switch 15 and releases it so that the door 14 can be opened.

When the support 10 is integrated with the platform 18, the door 14 also engages with the door opening shaft 24. The door 14 preferably has a shallow groove on its underside which mates with fingers and arms 25 at the top of the door opening shaft 24. Therefore, the door can be opened by the door opening shaft 24 after the pressure of the load lock is reduced and the differential pressure no longer holds the door 14 closed.

After the technician places the wafer support 10 in the vacuum load lock 12 and closes the load lock lid 20, a high pressure purge (dry nitrogen or dry nitrogen or It is preferable to apply other clean gas). This high pressure purge creates a vertical flow,
It tends to transport particles downwards and helps blow off some of the large particles that accumulate on the wafer support 10 during exposure to atmospheric conditions. After this initial purge step (eg, about 30 seconds or longer), the chamber is slowly depressurized to 10 ^-4 Torr or less. This depressurization step is preferably performed relatively slowly so as to avoid rolling up the irregular particulate matter. That is, low pressure causes particles to fall out of the air, but these particles are still on the bottom of the chamber and should be prevented from rolling up if avoidable.

The interior of the vacuum load lock stays at 10 ^{-4 to} 10 ^-5 Torr for a few seconds and drops out of the air to ensure that the particulate matter carried by the air actually falls out of the air in the chamber. It is preferable to ensure that all possible particles fall.

In an optionally modified embodiment of the present invention, a sloped bottom and / or a polished side wall of the load lock is used to attach to the side wall and bottom such that they may be ejected by mechanical vibration. It may be advantageous to reduce the population of entrained particulate matter. This invention significantly reduces the problem of airborne particulate matter, but this has always been the predominant mode of particulate matter transport and therefore the problem of ballistically transported particulate matter. Can be effectively taken up. An optional related variant is to use an in-place vacuum particle counter in the upper chamber,
Any increase in the population of particles within the volume of interest can be detected. Such in-situ particle counters use resonant circuits that measure charge transfer in high voltage vacuum gap capacitors, or laser driven optical cavities with multiple folding paths, or other It can be configured by means.

Optionally, use a particulate matter sensor (or a second particulate matter sensor that is better suited for sensing particulate matter at higher pressures) to control the nitrogen shower prior to the initial depressurization. You can That is, instead of just taking a nitrogen shower for a period of time, the shower can be extended if the particulate matter monitor indicates that the box is in an abnormally dirty environment. It may be desirable to depressurize the load lock (using a coarse pump) to a soft vacuum, then divert the gas through the nitrogen shower port to create a downward flow. If the particulate matter monitor indicates that the particulate matter level is still too high at the time the loadlock reaches the desired soft vacuum pressure, another load of the loadlock is initiated by initiating another nitrogen shower cycle. It may be desirable to use a cycle that raises the pressure from soft vacuum (eg, on the order of 100 millitorr) to atmospheric pressure.

Note that it is preferable to connect a vacuum gauge 62 inside the load lock chamber. Sensor 62 preferably includes a high pressure gauge (such as a thermocouple), a low pressure gauge (such as an ionometer), and a differential pressure sensor that accurately senses when the internal pressure of the loadlock is in equilibrium with the atmosphere. For this reason, the door of the support 10 is not opened until these instruments indicate that a good vacuum condition has been achieved inside the load lock.

After the coarse pump (not shown) depressurizes the chamber to soft vacuum, open the gate valve 39 and connect the turbo molecular pump 38 inside the load lock, then the turbo molecular pump
38 can be activated to bring the pressure to 10 ^-5 torr or less.

At this point, wafer support 10 and vacuum load lock
The pressure inside 12 is more or less balanced, and by operating the motor 26, the door 14 can be operated. Motor 26
Is connected to the door opening shaft 24 via a vacuum passage portion 25.

It is preferable to provide two sensor switches inside the vacuum load lock 12 to see when the door 14 is in the fully open position and when the door 14 is fully closed. That is, after decompressing the load lock 12 and keeping it in that state for several seconds, the door opening shaft 24 is rotated and the door 14 is opened until the sensor detects that the door is fully opened. During this time, transfer arm 28 is preferably held in place at a height below the bottom of the door to allow a gap for door 14 to open. After the sensor detects that the door 14 is fully open, the transfer arm operation can begin.

The transfer arm 28 preferably has two degrees of freedom.
One direction of movement allows the transfer arm 28 to reach into the support 10 or via port 30 to an adjacent process chamber. The other degree of freedom corresponds to the vertical movement of the transfer arm 28, which makes it possible to choose which wafer in the support 10 is to be taken out or in which slot to place it.

In the presently preferred embodiment, the lift drive motor 32 is used to control the height of the transfer arm 28 and the arm drive motor 34 controls the extension and retraction of the transfer arm 28. In the presently preferred embodiment, both motors do not require vacuum passages and the exhaust manifold
It is housed in 36. The manifold extends from the load lock 12 to a vacuum pump 38, which may be, for example, a turbo molecular pump. Further, the exhaust manifold 36 does not directly open into the load lock chamber 12 but has an opening 40 at the top thereof. That is, the exhaust manifold 36
Preferably, there is no line of sight from the drive motor 32 or 34 or from the pump 38 to the load lock chamber. This helps reduce the ballistic transport of particulate matter from such movable elements to the load lock chamber.

The lift drive motor 32 is preferably connected so as to drive the small platform 42 up and down, and the arm drive motor 34
Are preferably mounted on this platform 42.

In the presently preferred embodiment, the transfer arm 28
In order to be able to move very small,
A link mechanism is used inside the rotatable transfer arm support 44. The transfer arm support 44 is connected to a rotating rod, which is preferably driven by the arm drive motor 34, although the arm support 44 is preferably mounted on a non-rotating tubular support 46. Arm support 44 and transfer arm 28
It is preferred to use an internal chain and sprocket linkage so that the seam between the two moves at twice the angular velocity of the seam between the arm support 44 and the tubular support 46. (Of course, many other mechanical linkages could alternatively be used to do this.) That is, when the arm support 44 is in place, the wafer 48 supported.
Is generally above the tubular support 46, but when the arm support 44 is rotated 90 ° with respect to the tubular support 46, the transfer arm 28 is rotated 180 ° with respect to the arm support 44 and the transfer arm is It means that it can enter straight into the wafer support 10 or can enter straight into the adjacent processing chamber via the port 30. This linkage is based on pending US patent application serial no. 664,448 filed October 24, 1984.
It is described in detail in the issue.

The transfer arm 28 is preferably a piece of spring steel, for example 0.030 inch thick. The transfer arm has three pins 50 for supporting the wafer. Each pin 50 has a small shoulder
It is preferable to have a small cone 52 above 54. The cone 52 and shoulder 54 are preferably made of a material that is soft enough not to scratch silicon. In the presently preferred embodiment, these parts (which are the only parts of the transfer arm 28 that actually contact the wafer to be transported) are made of Adell (a thermoplastic phenyl produced by Union Carbide). -Acrylate) or high temperature plastics such as Delrin (ie, plastics that have a relatively low tendency to degas under vacuum). By using a cone 52 in the center of the alignment pin 50, a slight misalignment of the wafer with respect to the transfer arm 28 can be compensated. In other words, the wafer transport device of the present invention is a stable mechanical device, and small misalignments between successive operations do not accumulate and decay.

3 pins when positioning the wafer 48 as shown
Note that one of the 50 abuts the circumferential flat portion 56 of the wafer. That is, in this embodiment, the three pins 50 of the transfer arm 28 do not define a circle of the same diameter as the wafer 48 being handled.

In order to ensure that the flat portion 56 of the wafer does not interfere with the correct handling of the wafer, the box 10 has a flat surface on the inner backside thereof so that the flat portion 56 of the wafer 48 contacts it. A spring compression element inside the door 14 presses each wafer against this flat surface when the door 14 is closed so that the wafer does not rattle during movement.
This is also the flat part of each wafer 18 when the door 14 is opened.
It is a guarantee that the location of 56 is known exactly.

Therefore, when the box 10 is in the chamber 12 and its door 14 is open, the lift drive motor 32 is operated to move the transfer arm 28 just below the height of the first wafer to be taken out. Once in place, the arm drive motor 34 is then activated to place the transfer arm 28 inside the box 10. By operating the lifting drive motor 32 for a short time, the transfer arm 28
Is raised in this position, and the three pins 50 on its circumference lift the desired wafer from the bar 60 on which it was mounted in the carrier box 10.

Since the crosspiece 60 has a tapered surface instead of a flat surface,
Note that it is preferred that the contact between 60 and the overlying wafer 48 be a line contact rather than a surface contact and be confined to the wafer edge. That is, while conventional wafer supports can make surface contact over a significant area of many square millimeters, the "line contact" used in this invention is typically much smaller, on the order of a few square millimeters or less. Only touches the area. Another definition of "line contact" used in this embodiment of the invention is that the wafer support contacts the surface of the wafer only at points less than 1 mm from its edge.

Thus, by raising transfer arm 28, the desired wafer 48 is picked up and rests on cone 52 or shoulder 54 on three pins 50 of transfer arm 28.

In the presently preferred embodiment, the bars 60 have a center-to-center spacing of 0.187 inches in the box. This center-to-center spacing must be sufficiently less than the wafer thickness minus the transfer arm 28 height plus the pin 50 height, but much larger. There is no. For example, in the presently preferred embodiment, the thickness of the transfer arm is about 0.080 inches, including the height of cone 52 above transfer pin 50. The thickness of the wafer itself (in the presently preferred embodiment using a 4-inch wafer) is about 0.21 inch, which provides a clearance of about 0.085 inch. Of course, a wafer having a larger diameter has a larger thickness, but since the size of the box 10 and the center spacing of the bars 16 inside the box 10 can be appropriately changed, the present invention is applicable to such a wafer having a larger diameter. Especially suitable for.

Thus, after the transfer arm 28 picks up the desired wafer 48, the arm drive motor 34 is operated to move the transfer arm 28.
Bring in place.

The elevator drive motor 32 is then activated to bring the transfer arm 28 to a height where it can reach the port 30.

Unlike the gate 31 shown in FIG. 3, the port 30 is preferably covered by an isolation gate 31. The gate 31 preferably seals the port 30 without sliding contact. (As before, the absence of sliding contact is advantageous in that it reduces the amount of particulate matter generated internally.) In this embodiment, isolation gate 31 on port 30 is actuated by an air cylinder. Although preferably a stepper motor may be used instead. Therefore, a total of 4 motors are used. That is, two using vacuum passages and two preferably contained within the exhaust manifold 36. The arm drive motor is then activated again, extending transfer arm 28 through port 31 to the adjacent process chamber.

The adjacent processing chamber can be any of a number of different types of processing units. For example, this processing unit is a driving device,
It may be a plasma etch part or a deposition part.

In the presently preferred embodiment, the transfer arm through port 30 has wafer 48 on three pins 50 as shown in FIG. 3, similar to those used on the transfer arm itself.
Put on. (Port 30 has a vertical height that allows it to move slightly vertically while extending arm 28 through port 30.
Note that it is preferable to be able to move vertically from 50 to lift or lower the wafer onto this pin. Alternatively, the process chamber may have a jig with spaced ramps similar to the rungs 16 in the transfer box, or other mechanical device for receiving wafers. May be. However, in any case, the equipment used to receive the transferred wafers has a gap under the wafers (at least during transfer) and
It must be possible for 28 to enter the underside of the wafer in order to place or remove it. When using the pin 50 to receive the transferred wafer, in order to perform the vertical movement of the wafer support pin in the processing chamber,
It may be desirable to provide a bellows movement or vacuum passage. That is, for example, if the process chamber is a plasma etch or RIE (reactive ion etch) section, a through hole is provided to allow the transfer arm 28 to be retracted from the wafer path and then the wafer to rest on the receptor. Can be positioned.

Of course, the processing unit may be a technical inspection unit. It is possible to inspect wafers in which the microscope objective, which is isolated by a vacuum, is in a vacuum state (using an appropriately bent optical path) and is in a face down orientation. In other words, use technician's inspection extensively, when appropriate, without the technician's time being spent and the risk of the clean room being compromised by the high volume of clean room passage. Can be done.

In any case, it is preferable to retract the transfer arm 28 and close the isolation gate above port 30 while the process proceeds. After the process is complete, the isolation gate above port 30 is reopened, arm 28 is re-extended, and lift drive motor 32 is briefly actuated to cause arm 28 to pick up wafer 48 and arm drive motor 34 again. Operate to bring transfer arm 28 back into place. The lift drive motor 32 is then actuated to bring the transfer arm 28 to the correct height to align the wafer 48 with the desired slot in the wafer support. The arm drive motor 34 is then activated to place the transfer arm 28 into the wafer support 10 so that the freshly processed wafer 48 sits on the pair of bars 60. After that, the lift drive motor 32 is operated for a short time, and the transfer arm 28
Down so that the wafer rests on its own rail 60 and the arm drive motor 34 is activated to retract the transfer arm 28 into place. The sequence of steps just described is then repeated and transfer arm 28 selects another wafer for processing.

Using the mechanical linkage of the transfer arm 28 and the arm support 44 as described above, if the lengths between the centers of the transfer arm 28 and the arm support 34 are equal, the transferred wafer is exactly straight. To move. This is advantageous as it means that the side surfaces of the wafer being transferred do not hit or scratch the side surfaces of the box 10 when the wafer is withdrawn from or pushed into the box. That is, even if the gap in the wafer support box is relatively small (which helps reduce the generation of particulate matter due to wafer wobbling during transport in the support), the wafer is supported by the metal side of the box. There is no danger of producing particulate matter due to abrasion.

In this manner, wafer-by-wafer processing continues until all the wafers in support 10 (or at least as many wafers as desired) have been processed. At that point, transfer arm 28 is returned to its empty, stationary position, lowered below the lower edge of door 14 and the isolation gate above port 30 is closed. Next, rotate the door opening shaft 24 to close the door 14,
When the first contact of the vacuum seal between 14 and the flat front side of the support 10 occurs, thus increasing the pressure in the loadlock, the support is ready to be sealed (due to the differential pressure).
At this time, the load lock 12 can be pressurized again.
When the differential pressure sensor of the vacuum gauge 62 determines that the pressure has reached atmospheric pressure, the load lock lid 20 can be opened and the wafer support 10 (which is sealed by the differential pressure at this time) can be removed by hand. I can. In the preferred embodiment, a folding handle 11 is provided above the support to aid in this manual removal without significantly increasing the volume of the support required within the loadlock.

After removing the support, it can be carried or stored if desired. The seal 13 maintains a high vacuum in the support during this time, which minimizes particulate matter transport (as well as vapor phase contaminant adsorption) to the wafer surface.

Elastic element 27 with wafer support attached to its door
Note that you also have Such elastic elements exert a light pressure on the wafer 48 when the door 14 is closed, thus restraining the wafer from rattling and producing particulate matter. Although the elastic element 27 is configured in the illustrated embodiment as a set of springs, other mechanical structures (eg, protruding ridges of elastic polymer) can be used instead. If the wafer used has a flat surface, the flat surface of the slice should be pressed into contact with the wafer support box.
It is preferable to provide a flat contact surface 29 on the inner rear surface of 10.

Note that the crosspiece 60 on the side wall of the support box 10 is tapered. This helps ensure that the contact with the supported surface of the wafer is made only along the lines, not a substantial area. This reduces wafer damage and the generation of particulate matter during shipping. Furthermore, this helps eliminate the accumulation of positioning errors, as previously mentioned.

The loadlock lid 20 is preferably provided with a window to allow the operator to inspect for any mechanical snags.

An advantage of the present invention is that in the event of various possible mechanical malfunctions, the wafer support 10 door can be closed before attempting to correct the problem.
For example, if the transfer arm 28 picks up a wafer so that it does not sit correctly on all three pins 50, the door drive motor 26 is actuated to close the door 14,
Attempts can be made to remedy this problem. Similarly, if transfer arm 28 can be retracted into position, port 30 can be closed. It is possible to correct some such mechanical misalignment problems by simply changing the normal control sequence. For example, in some cases, the transfer arm 28 may be partially extended so that the edge of the wafer 48 just touches the outside of the isolation gate on the door 14 or port 30 to remove the wafer 48 on the transfer arm 28. The position can be adjusted. If this doesn't work (while the door 14 of the wafer support 10 is closed), return the load lock 12 to atmospheric pressure and remove the load lock lid.
You can open 20 and fix the problem manually.

Note that it is very easy to control all the actions mentioned above. That is, no servo or complicated negative feedback mechanism is required. All four motors mentioned above are simple stepper motors, so that multiple stations of the present invention can be controlled by a single microcomputer. Mechanical stability of the entire device, i.e. inherent correction of small positioning errors due to the taper pins of the wafer support, the inclination of the wafer support rails of the wafer support, and the flats on the back wall of the wafer support. Helps prevent small errors from accumulating and allows easy control.

This advantage of simple control is partly due to the good control of the mechanical alignment achieved. As previously mentioned, the integration of the support 10 with the platform 18 provides one element of mechanical alignment. This is because the position of the platform 18 with respect to the transfer arm 28 can be accurately and permanently calibrated. Similarly,
Wafer support 10 need not be controlled in each dimension,
It only has to be controlled so that the position and orientation of the support shelf 60 with respect to the bottom (or other part) of the box that mates with the support platform 18 can be accurately determined. As I said before, this is
Many different mechanical devices may be used, although this is preferably accomplished by providing a channel along which the wafer support slides until it rests on the platform 18.

Similarly, mechanical alignment must be achieved between the home position of the transfer arm 28 and the support pins 50 (or other support type) that mate the wafer with it inside the process chamber. However, this mechanical alignment should be a simple one-time set calibration.

As mentioned previously, the box itself protects angular positioning. When the door 14 is closed, the spring elements, both inside it, press the wafer 48 against the flats on the inside rear surface of the box.

Optionally, the wafer support 10 may be provided with a quick connect vacuum fitting to provide a separate vacuum to the support 10. However, this is omitted in the presently preferred embodiment. Because it is not necessary, and it can be another source of reduced reliability.

The load lock mechanism described so far, although it being the most preferred embodiment, need not be used solely for vacuum tight wafer supports. This load lock can also be used for wafer supports that have atmospheric pressure inside. This is not the most preferred embodiment, but as mentioned earlier,
It still has significant advantages over traditional loadlock work.

It should be noted that the wafer supports described above can be made in different sizes to carry any desired number of wafers. Further, the wafer support of the present invention can be used to carry or store any desired number of wafers up to the maximum. This provides extra flexibility in terms of planning as well as process equipment logic.

FIG. 5 shows another embodiment in which two loadlocks, each having a wafer support 10, are both connected to a process module 102 having four process stations 104. As the transfer arm 28 enters the process module 102 from the load lock 12 through port 30 it places the wafer on one of the two wafer stages 106. As previously mentioned, such a wafer stage 106 may be a support with three pins, or a support with two crosspieces, or other machines contemplated by those skilled in the art. However, below the wafer to be supported, the transfer arm 28 can lower the wafer away from the wafer after the transfer arm 28 places the wafer on the support. There must be a space for (However, the wafer support used is preferably one that makes line contact with the lower surface of the wafer, rather than over a substantial area.) Another transfer arm assembly may be present in the process module.
106 are provided. This transfer arm assembly is generally similar to the transfer arm assembly 28,44,46 used inside the load lock, with some differences. First, the transfer arm 28 used inside the loadlock need only move the wafer in a straight line. In contrast,
The transfer arm assembly 106 must also be able to move radially to select any one process module 104. For this reason, another degree of freedom is needed. Second, the range of movement of the transfer arm assembly 106 is the transfer arm assembly 2 used inside the loadlock.
It does not have to be the same as 8,44,46, in fact the transfer arm 106
The range of movement is preferably larger so that the process stations 104 can be properly spaced. Third, the arm assembly 106 does not have to move as much in height as the transfer arm 28 used in the loadlock. Fourth, in the form shown, transfer arm 128 has three
One of the two pins 50 does not rest on the flat part of the wafer, thus they handle wafers of the same diameter,
The diameter of the circle drawn by pin 50 is not the same for arms 28 and 128.

With these differences, transfer arm assembly 106 is essentially a transfer arm assembly 28,44, used in a loadlock.
It is preferably the same as 46. By allowing the tubular support 46 to rotate and providing a third motor to drive this rotation, a third degree of freedom of the transfer arm is obtained. Similarly, the dimensions of the transfer arm can be easily changed if desired. Therefore, the transfer arm assembly 106
It preferably includes a transfer arm 128 rotatably mounted on the transfer arm support 144. A transfer arm support 144 is pivotally attached to a tubular support 146 (not shown) with an inner shaft fixed to the transfer arm support 144 extending downwardly within the tubular support 146. If the internal chain drive with a 2 to 1 gear ratio has a discriminating rotation between the tubular support 146 and the arm support 144, then it is a different discrimination between the arm support 144 and the transfer arm 128. Rotation (over twice the frequency)
Convert to. An arm drive motor mounted below the transport assembly 106 is connected to rotate a shaft fixed to the arm support 144. Arm rotation motor is tubular support
Connected to rotate 146. Finally, the lift mechanism causes vertical movement of the transfer arm assembly 106.

The vertical movement required for assembly 106 is typically not as great as required for transfer arm 28 within load lock 12. This does not require selecting one of several vertically spaced wafer positions, such as the one in which the transfer arm 128 is typically in the wafer support 10, and typically simply It is only used to pick up or place a wafer from several possible wafer stations, all on the same plane. Thus, the vertical height of the transfer arm 128 can optionally be controlled by the pneumatic cylinder rather than by the lifting motor assembly as previously described.

Therefore, by rotating the tubular support 146 at the same time as the arm support 144, the transfer arm assembly 106 can be rotated without being extended. After the arm support 106 is rotated to the desired position, the arm support 144 can be rotated while the tubular support 146 is fixed. This causes the transfer arm 128 to extend as previously described.

Thus, after one transfer arm 28 from one loadlock 12 has placed a wafer to be processed on one wafer stage 106, the transfer arm assembly 106 is rotated (if necessary) to a lower position. It can be extended so that transfer arm 128 is below the wafer and raised so that transfer arm 128 picks up the wafer and retracts into place. The assembly 106 is then rotated again and the transfer arm 128
The wafer is now in one process solution 104, above the wafer support or on another wafer.
It should be above stage 106. By lowering the arm assembly 106, the wafer can now be placed on the wafer support or wafer stage, where the arm 128 can be retracted.

At this time, the process station 104 can be sealed from the main process module 102 and a separate single wafer processing of the wafer can begin. Meanwhile, the transfer arm
128,28 can do other work. Module 10
When the processing of the wafers in 4 is completed, the process station 104 can be depressurized to the same low pressure as inside the process module 102 and the process station 104 can be opened. The transfer arm assembly 106 can then be actuated to remove the wafer and transfer it to one wafer stage 106 or another process module 104.

One advantage of the present invention is that process module 104
Can all be configured to do the same work. This allows wafer throughput to be limited by transport (even for fairly slow processing operations), or different, provided there are a sufficient number of process stations 104 within the process module 102. Different tasks can be performed at process station 104.

That is, the present invention allows for sequential processing because it eliminates process variability due to adsorbed contaminants or native oxides, which is recognized as increasingly desirable. For example, two process stations 10
4, can be configured for oxide growth, one for nitride deposition and one for poly deposition, thus completing in-situ fabrication of oxynitride poly-poly capacitors You can Further, using different process steps at different stations 104 allows multiple lot splitting and splitting by programming the appropriate operations without the technician relying on correctly ascertaining which wafers enter which equipment. It means that process changes can be made. Thus, allowing different operations to proceed at different process stations provides another flexibility of processing.

It should also be noted that the overall wafer transfer sequence is completely arbitrary and can be selected as desired.
For example, a wafer from one wafer support 10 may be completely processed and returned to that wafer support 10 with the loadlock 12 containing the wafer just processed sealed from the process module 102, and the like. Road lock 12
Process the wafer on another wafer support 10 at
Meanwhile, a technician can remove the support full of processed wafers from the other load lock 12. Alternatively, the programmability and random access of this configuration can be used to transfer or exchange wafers between the two supports 10 in any desired manner.

This configuration is in no way limited to two loadlocks 12 or four process stations 104, and the configuration described here may be any other number of process stations 104 or modules 102 in module 102 attached to It should be noted that any number of loadlocks 12 may be modified, or if desired, more than one transfer arm assembly 106 may be used within a module.

Note that this configuration orients the wafer in that direction. Assuming that the wafer has its flats supported within the support 10 with the backside of the support 10
The wafer is placed on the wafer stage 106 with its flat portion facing the center of the module 102. The transfer arm 106 keeps this orientation so that when the flat is returned to either wafer support 10, the flat of the wafer faces the back of the box.

Described below is a group of embodiments of the invention that implement the ideas described in the other applications for another particular case.

Note, for example, in FIG. 5 of that other application, the device can be configured to have only one transfer arm, rather than three. That is, the wafer support reaches the wafer support directly through the open port of the central transfer arm 106 with respect to the central transfer arm 106,
The wafer can be positioned so that it can be removed without the use of two local transfer arms 28 in the load lock 12. The advantage of this approach is that it eliminates the use of extra mechanisms, controls and vacuum passages to actuate transfer arm 28. The downside is this time the arm assembly 10
The movement of the vertical axis of transfer arm assembly 106 must be increased because 6 must be able to access the entire range of slices stacked in wafer support 10 as well as picking and unloading wafers. That is something that must be done. Second, the access port 30 has to be made larger. That is, the boat 30 must have sufficient vertical extent to allow the transfer arm assembly 106 to pass through it at any wafer height within the support 10. I have to. Another drawback is that the transfer arm assembly 106 must extend over a greater physical distance than would otherwise be necessary. This means that it is more difficult to construct and operate this arm so as to avoid positioning errors. (If we consider the mechanical positioning controller of this device as a control system, the wave action of the error obtained by the temporary location of the wafer on the stage 105 is eliminated, and at this time the transfer arm assembly 106 is required. A longer physical extension means that a larger raw error is introduced in terms of positioning.) Furthermore, the device is not so modular and cannot be easily expanded. Thus, while this group of embodiments is less preferred at present, it is nevertheless a viable group of embodiments of the present invention, which may and may in the future be considered even more desirable. I have included it here to complete the explanation.

Another group of embodiments uses differently shaped wafer supports. A variety of wafer support shapes can be used, as described in the above-referenced other application. Next, the shape of another wafer support will be described in detail.

In this form, as shown in FIG. 1a, the wafer support 10 '
Instead of having an openable sealing door 14, it has a riseable sealing cover 14 'which is connected to the body of the wafer support by a vacuum seal 13'. In this example,
A handle 11 'is provided on top of the cover 14' for transporting the assembly and for removing the cover. Hasp attached to board 202
5'is provided to engage the bottom bar 204 of the cover, thus leaving the cover attached to the body of the support 10 'regardless of whether the seal 13' is tightly closed in vacuum. Assure. For this reason, by adding an extra element called a safety latch 15 'to the plate 202, the modified wafer support shape
You can use 10 '. (This modified wafer support shape is very similar to one conventional device, namely that sold by VG Systems, Inc.) ie 1a.
The embodiment shown in FIGS. 1 to 1e is a modification of the basic wafer support that is commonly used in some prior art equipment to allow such wafers in a vacuum processing apparatus such as that described in that other application. Allow the support to be used.

Note that on plate 202, latch 15 'has a boss 206 along its base that provides a location for the periphery of boss 204 at the lower edge of cover 14'.

In this embodiment, the platform 18 'is a positioning pin.
It has been modified to have 21, one coaxial with the overall cylindrical shape of the wafer support and a second away from the axis to allow control of the radial orientation of the wafer support. ing.

For this reason, in this embodiment, the latch 15 'is manually opened and the sealed support assembly 10' is manually operated on the platform 18 '.
Place on top of. Close the load lock lid and vacuum seal 1
After decompressing the load lock so that 3'is released, the cover 11 'can be separated from the body of the support, so that the wafer inside the body of the support 10' will be as described above. It can be accessed by the transfer arm 18.

A configuration is also conceivable in which the cover is lifted from the main body of the support. However, more preferably, as shown in FIG.
The body 210 of the wafer support 10 'is first supported on the stage 212. This stage supports platform 18 '. The mechanical transport element 214 then lowers the stage 212 so that the cover 14 'is still supported by the floor 216 above the load lock 12', but the body 210
Can be lowered into the lower chamber 218 of the load lock 12 '.

In the preferred form of this embodiment, the substrate 202 and safety catch 15 'are used only to transport or store the wafer support outside of the loadlock chamber and support it prior to placement in the loadlock 12'. It is manually removed from the base of body 10 '. Therefore, in this embodiment, the wafer support 10 '
Cover 14 'of the load locks in place within the upper chamber 219 of the load lock and provides a dust barrier between upper chamber 219 and lower chamber 218 that is exposed to particulate matter when cover 20' is opened. Become. With the support body 210 in the lower chamber 218 when the cover 14 'is not in place, the stage 212 itself provides a dirt barrier to the underside of the partial floor 216. Furthermore,
A vacuum seal 220 may be provided to use the upper chamber 219 itself as the only load lock and keep the lower chamber 218 in a vacuum. This is not always desirable, but is an optional use of this embodiment. In addition, this shape improves the segregation of debris as it has a relatively slight smooth surface in the upper chamber 219 that is most directly exposed to debris and is thus easier to blow off particulate matter. To be done. Thus, in this example, the upper chamber 219 is connected to the purge port 22 'as well as the vacuum port 36'. Purge gas can be passed through port 22 'when the upper chamber 219 is sealed and depressurized for coarse. For example, it may be desirable to blow moist air or partially ionized clean gas from port 22 'to reduce electrostatic sticking of particulate matter.

This alternative embodiment has the additional advantage that the wafer itself does not even see the surface of the load lock exposed to particulate matter when loading the support into the lock. For this reason, the wafer support body and the wafer in it never see the dirty ambient atmosphere,
You will never even see the exposed surface in the dirty surroundings.

The effectiveness of this dust seal between the cover 14 'and the partial floor 216 can be further enhanced by adding another sealing element. For example, a vacuum O-ring can be fitted to the floor 216 and sealed against the smooth surface under the cover flange, such that the support body surrounds the mating opening. Although less preferred, a separate O-ring can be provided on the support cover itself.

In addition, the O-ring and the resulting improved vacuum and debris isolation can be used to allow alternate (alternative and optional) modes of operation. The upper chamber is vacuum sealed, whether it is between the lower edge of the wafer support cover and the partial upper floor, or between the liftable stage and the partial upper floor. However, if it is always isolated from the lower chamber, the pressure as well as the cleanliness of the upper chamber is less critical. In some applications where it is desired to improve the throughput of the loading operation, it may be desirable not to depressurize the upper chamber to the low pressures and particulate matter numbers required for actual wafer transfer. For example, in this extreme case, the upper chamber could simply be used as an air shower chamber to remove coarse particulate matter,
It can create an atmosphere comparable to a normal clean room. Alternatively, if you want to perform very high vacuum operations (such as molecular beam epitaxy (MBE)), which typically require pressures of 10 ^-10 torr or less, then the upper chamber should be 10 ^It can be used for coarse decompression down to about ^-5 Torr to reduce the load on the ultra high vacuum equipment in the lower chamber.

In this alternate embodiment wafer support, the wafer-bearing bars 60 are still used, but this time, as seen most clearly in the plan view of FIG. 1c, two rows 226 of opposite sides are provided. And supports the wafer holder 224 by line contact.

Note that in this embodiment, wafer holder 224 is used in place of unattached wafer 48.
This modification is not particularly advantageous, but results in a different embodiment of the invention that is compatible with other existing processing equipment. Figure 1e shows
Wafer holder 224 by spring 227 that spreads wafer 48
It is a detailed view showing a state where it is fixedly held inside. In any case, whether a bare wafer or a wafer support is used, as described in the other application and the description of the specification up to now, in order to prevent the generation of particulate matter, It is desirable to reduce the contact area of the. Therefore,
For the reasons set forth in the above-noted other application, the crosspieces 60 that support the sides of the wafer 48 (or wafer holder 224) are preferably tapered.

In a particular embodiment using the wafer holder 224, the wafer holder 224 has a notch 229 that engages the back support bar 228. This notch helps to ensure radial wafer positioning. In other words, this behaves the same as the flat backside of the wafer support 10 in pressure contact with the flat portion of the wafer 48 when using a bare wafer.

In this embodiment, the side support pillars 226 and the rear support rods 228 are
Are joined at the top by an upper support member 211 (which includes the handle extension), which provides mechanical robustness to allow manipulation of the exposed wafer support body 210.

In this embodiment, instead of the spring 27 being located in the door 14 as before, a spring 27 that prevents wafer rattling during shipping is used.
It is arranged as a spring 27 'in the lateral support column 226. This means that more force may be required to remove and replace the wafer in the support, so this extra force can be applied without the wafer slipping off the pins. Transfer arm 28
It may be desirable to make the top pin taller.

It will be appreciated by those skilled in the art that the present invention can be modified significantly and its scope is limited only by the claims.

 The following section is further disclosed in connection with the above description.

(1) A wafer support body having a support body that includes a crosspiece that is tapered so as to support a flat disk, which is substantially in line contact and not in surface contact, and the support body is a base portion. And the base has a vacuum seal surrounding the side support,
Further, the wafer support body has a cover that fits the vacuum seal, the cover, the vacuum seal, and the main body constitute a vacuum-tight cover, and the cover is normal to the plane of the vacuum seal. A wafer support which is detachable from the main body in a line direction.

(2) The wafer support described in the item (1) further includes a latch plate, and the latch plate includes a latch for holding a cover of the wafer support on the wafer support body. A wafer support that is removable from the wafer support and the wafer support body without disturbing the vacuum seal between the wafer support and the wafer support body.

(3) In the wafer support described in item (2), the cover is limited by the crosspiece of the side surface support member.
A wafer support that can be attached and detached in the direction approximately normal to the direction of two disks.

(4) The wafer support as described in the item (3), wherein the support body has a rear support member having a sloped support surface.

(5) The wafer support as described in the item (4), wherein the wafer support body has a shape on its outer surface that limits a mechanical position.

(6) A main body including a side wall, and a cover that can be closed together with the main body so as to form a vacuum-tight seal, and each of the side walls defines a plurality of slots for holding a wafer having a predetermined size. A crosspiece, and at least one face of the crosspiece on the side wall,
At least 5 ° from a direction parallel to the plane of the slot
Wafer support with a slope that can be displaced.

(7) A main body including a side wall, and a cover that can be closed together with the main body so as to form a vacuum-tight seal, and each of the side walls has a plurality of slots that define a slot for holding a wafer having a predetermined size. A crosspiece, and at least one face of the crosspiece on the side wall,
There is an inclination of at least 5 ° from the direction parallel to the plane of the slot, and further, an elastic element is provided on the inner surface of the support, and the elastic element is fixed so as not to freely move a wafer having a predetermined size. Holds the wafer support.

(8) It has an upper chamber and a lower chamber, a stage that can be moved up and down, and a transfer arm, and the upper chamber has a lid that can be opened large enough to accommodate a wafer support, and the upper chamber is a partial chamber. A wafer support having a general floor and having an opening in the floor, the floor having a predetermined shape with a removable cover that can be vacuum sealed to the body, but not the body but the cover. The stage that can be moved up and down can be translated, and at the limit of one movement,
Supporting the body of the wafer support located in the opening in the floor of the upper chamber, and moving from the limit of one movement of the body of the wafer support through the opening in the lower chamber. And the cover of the wafer support is still supported by the partial floor of the upper chamber, and the upper floor between the cover and the partial floor of the upper chamber. A seal configured to seal at least a part of the particulate matter between the side chamber and the lower chamber is configured, and the transfer arm is disposed on the stage capable of moving up and down below the floor of the upper chamber. A load lock device arranged to retrieve the wafers one by one in a programmable sequence from the body of the wafer support during operation.

(9) The load lock device according to the item (8), wherein the upper chamber has an exhaust port.

(10) In the load lock device described in the items (8), the upper chamber has a first exhaust port and the lower chamber has a second exhaust port.
Load lock device connected to the exhaust port of the.

(11) In the load lock device described in the paragraph (8), the upper chamber has both a first exhaust port and a purge port, and the lower chamber is a first exhaust port separate from the first exhaust port. Load lock device with 2 exhaust ports.

(12) In the load lock device according to the item (8), when the stage is positioned so as to substantially support the main body of the wafer support disposed in the upper chamber, the stage is A load lock device that creates a vacuum tight seal with the partial floor of the upper chamber.

(13) In the load lock device as described in the item (8), the lower chamber has a transfer arm, and the transfer arm has a wafer support body placed on the stage when the stage is lowered. A load lock device that is positioned to enter and exit the wafer support body and selectively into and out of the wafer support body.

(14) In the load lock device according to the item (8), the groove hole of the wafer support holds a wafer holder having a predetermined size, and the wafer holder is an integrated circuit wafer. A load lock device for directly supporting the wafer, and the transfer arm and the wafer support directly contact not the wafer but the wafer holder.

(15) In the load lock device described in the item (8), the floor of the upper chamber does not hinder the movement of the main body of the support,
A load lock device having a seal positioned for intimate contact with the cover of the support such that the cover provides a barrier to particulate matter between the upper chamber and the lower chamber.

(16) The load lock device as described in the paragraph (15), wherein a seal between the floor of the upper chamber and the cover of the support is vacuum-tight.

(17) A plurality of wafers are prepared in a wafer support that can be vacuum-sealed, and the wafer support has a cover that is vacuum-sealed in its main body, and the cover is a wafer supported in the main body. A load which is detachable from the main body in a direction substantially normal to the plane and has a partial floor having an opening and a stage disposed below the opening in close proximity to the floor. The wafer is placed in a lock upper chamber, the load lock upper chamber is depressurized to a pressure of less than 10 ⁻⁴ Torr, the stage is lowered, and the cover is supported on a partial floor in the upper chamber. However, the main body containing the wafer is lowered into the lower chamber and the inside of the adjacent vacuum-tight space connected to the lower chamber is completed until the desired sequence of processing operations is completed. One or more enclosed in Transfer the wafers from the wafer support to the selected process station in a desired sequence under vacuum and then raise the stage to move the body of the wafer support back to the cover of the wafer support again. A method of manufacturing an integrated circuit comprising the steps of bonding and forming a vacuum seal therebetween, venting the upper chamber to the environment, and removing the wafer support from the upper chamber.

(18) In the method described in paragraph (17), when the stage is substantially at its upper position, the stage creates a vacuum seal between the upper chamber and the lower chamber, and While removing or replacing the wafer support from the upper chamber,
A method wherein the upper chamber is hermetically sealed from the lower chamber.

(19) In the method described in (17), the upper chamber has an exhaust and purge port separate from the lower chamber, and a clean gas is used before lowering the stage. And purging the upper chamber to reduce particulate matter therein.

(20) In the method described in the paragraph (17), when the wafer support is placed therein and the lid of the upper chamber is closed, the inside of the upper chamber is different from the exhaust and purge ports. And the method that only the smooth surface is exposed.

(21) The method described in paragraph (17), wherein the pressure in the wafer support is less than 10 ⁻⁴ Torr when the body of the wafer support is resealed with the cover of the wafer support.

(22) In the method described in (17), the size of the slot of the wafer support is such that a wafer holder having a predetermined size is held, and the wafer holder is an integrated circuit wafer. The method of directly supporting.

(23) In a method of transporting an integrated circuit wafer during manufacturing, a vacuum state is provided in a vacuum-tight support having a body including sidewalls and a cover that can be sealed together with the body to form a vacuum-tight seal. The step of carrying the wafer at, the side wall having a plurality of rails each forming a slot for holding a wafer having a predetermined size, and at least one surface of the side wall rail having the slot. A method in which there is a slope offset by at least 5 ° from a direction parallel to the plane.

(24) In a method of transporting an integrated circuit wafer during manufacturing, put it in a vacuum-tight support having a main body including sidewalls and a cover that can be sealed together with the main body to form a vacuum-tight vacuum state. The step of transporting the wafer with the side wall has a plurality of rails that define a slot for holding the wafer, each of which has a predetermined size, and the side wall has at least one surface of the rail with a plurality of rails. Inclined at least 5 ° from a direction parallel to the plane, and said support has an elastic element on its inner surface, which elastic element holds the wafer of said predetermined size firmly so that it does not move freely. how to.

(25) A desired manufacturing process is carried out at a plurality of process stations separated by an atmosphere of approximately atmospheric pressure, and an integrated circuit wafer manufactured halfway is transported between the process stations, Performing a predetermined sequence of processing steps on the wafer, wherein the transporting step includes a vacuum-tight seal having a body that includes sidewalls and a cover that can be sealed together to form a vacuum-tight seal with the body. The method includes the step of placing the wafer in a support and carrying the wafer in a vacuum state, wherein each of the side walls has a plurality of rails each forming a slot for holding a wafer having a predetermined size, and at least one of the rails on the side wall. The two surfaces are inclined by at least 5 ° from a direction parallel to the plane of the slot, and the support has an elastic element on its inner surface, the elastic element having a predetermined size. -A method of manufacturing an integrated circuit that securely holds a motor so that it does not move freely.

(26) In the method described in the paragraph (25), the wafer support has a groove hole dimension to hold a wafer holder having a predetermined dimension, and the wafer holder is an integrated circuit wafer. How to directly support.

(27) Prepare a plurality of wafers in a wafer support that has a cover that can be vacuum-sealed in the main body that has a slot for holding wafers, and load-lock a load-lock that can be vacuum-sealed attached to the process module. Placing the wafer support therein and decompressing the load lock to a pressure of less than 10 ⁻⁴ Torr so that the vacuum seal between the body of the support and the cover of the support is released. Remove the body of the support from the cover while it remains in the lock so that the wafer inside the body of the support is within line-of-sight of any substantial portion of the interior of the load lock. The wafer support body into the body of the wafer support, and then removes one selected wafer from the wafer support body until the desired sequence of processing operations is completed. Transferring the wafer from the body to one or more selected process stations under vacuum and vice versa, and then closing the wafer support to increase the pressure of the load lock to about atmospheric pressure, thus A method of manufacturing an integrated circuit comprising causing the wafer to remain in a vacuum state within the wafer support while the wafer support is held closed by a differential pressure.

(28) In the method described in the paragraph (27), the transfer arm can be moved up and down and extended, and the transfer arm has a supporting element, so that one wafer having a predetermined diameter is brought into line contact. A method that can be supported only by the transfer arm.

(29) The method according to the item (27), wherein the wafer support is supported only by a line contact without contact with a substantial area of the lower surface of the wafer.

(30) In the method described in (27), the size of the groove hole of the wafer support is adapted to hold a wafer holder having a predetermined size, and the wafer holder is an integrated circuit wafer. How to directly support.

[Brief description of drawings]

FIG. 1 is a perspective view of one embodiment of the vacuum load lock of the present invention, showing the wafer support of the present invention during the loading and unloading process. FIGS. 1A-1E show another embodiment in which the wafer support is configured to have a liftable sealing cover coupled to the body of the wafer support by vacuum sealing instead of an openable sealing door. Figure, Figure 2 is a graph showing the time required to fall in air at various pressures for various sizes of particulate matter, and Figure 3 shows an example wafer transfer structure at a processing station. , A partially broken perspective view showing a wafer being placed on three pins by a transfer arm from an adjacent load lock through a port. FIG. 4 is a detailed view of one embodiment of the wafer support incorporated with a platform inside the loadlock to mechanically align the wafer positions, and FIG. 5 shows four process stations, two wafers. FIG. 6 is a plan view of an example processing module including a transfer stage and a load lock adjacent each wafer transfer stage. Explanation of main symbols 10: Wafer support 12: Vacuum load lock chamber 14: Wafer support door 18: Platform 20: Lid 24: Door opening axis

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Robert Alan Bowling, Rockstock Crest Drive, Garland, Texas, USA 3417 (72) Inventor Teimosie. Wooldredge Crestover Circle 402 (72) Inventor Doyuan Yi, Richardson, Texas, USA. Carter Windy Meadow, Plano, Texas, United States 5005 (72) Inventor Jiyoung Yi. Spencer Potomac Drive, Plano, Texas, USA 1401 (72) Inventor Randall See. Hilden Brand Westover 634 (56), Richardson, Texas, USA (56) Reference JP-A-60-143623 (JP, A)

Claims (1)

(57) [Claims] 1. A base, a support provided in a central region on the base and integrally with the base, the support including a crosspiece for supporting a wafer, and a vacuum seal formed in a peripheral region on the base. A wafer support body comprising: a wafer support body; and a cover having an opening end portion, the cover forming a sealed space in which the support portion is accommodated by contact between the vacuum seal and the opening end portion.