JPH06103716B2 - Semiconductor wafer holding hand - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel semiconductor wafer holding hand.

More specifically, the present invention relates to a semiconductor wafer holding hand for holding semiconductor wafers stored in a storage carrier in a hierarchical manner and taking them in and out of the storage carrier.
An object of the present invention is to provide a novel semiconductor wafer holding hand having a function of aligning a semiconductor wafer.

[0003]

2. Description of the Related Art The transfer of semiconductor wafers is generally in the shape of a box, and several tens of them are stored in a storage carrier having many shelves.
It is carried out in a state where a plurality of semiconductor wafers are stored in a hierarchy,
In addition, the movement of the semiconductor wafer for loading and unloading the semiconductor wafer stored in such a storage carrier into the apparatus in each step is performed by a robot equipped with a semiconductor wafer holding hand that is movable in the horizontal direction and the vertical direction.

By the way, when the semiconductor wafer is processed in each step, it is necessary that the semiconductor wafer has a fixed orientation.

For this reason, a semiconductor wafer is usually provided with a notch edge obtained by linearly cutting a circular peripheral portion, that is, an orientation flat, in order to perform alignment in the circumferential direction. Then, in a conventional semiconductor wafer transfer system in a semiconductor manufacturing process, a positioning device is arranged everywhere, and the semiconductor wafers stored in a storage carrier are taken out one by one and set in a predetermined direction. At the same time, they were working to return it to the storage carrier.

[0006]

As described above, conventionally, since the alignment apparatus for aligning the semiconductor wafer has been arranged everywhere in the semiconductor wafer transport system, a large number of semiconductor wafers are provided in the transport system. An alignment device is required, a special space for arranging the alignment device is required, and the work performed by each alignment device is an independent process by itself. There was a problem that the number of processes would increase.

The work performed by each alignment device is as follows.
Since it is a work to take out the semiconductor wafers one by one from the storage carrier and align them in a predetermined direction and return them to the storage carrier, it takes a lot of time for the alignment, and frequent loading and unloading of the semiconductor wafers causes dust. This means that the chances of adhesion and surface abrasion increase.

[0008]

In order to solve the above problems, the semiconductor wafer holding hand of the present invention has a thickness smaller than the space between vertically adjacent semiconductor wafers housed in a housing carrier. Part, a turntable rotatably supported by the tip of the hand part, the upper surface of which is positioned so as to project slightly from the upper surface of the hand part, drive means for rotating the turntable, and the turntable mounted on the turntable. An orientation flat detection means for detecting an orientation flat formed on the peripheral portion of the placed semiconductor wafer is provided.

[0009]

Therefore, the semiconductor wafer holding hand of the present invention has a function of aligning the semiconductor wafer in addition to the original function of holding the semiconductor wafer. It is possible to perform the above, and it is not necessary to provide a dedicated alignment device for aligning the semiconductor wafer in the semiconductor wafer transport system. Therefore, the transport system can be downsized by that amount, and only the alignment is required. It is possible to reduce the number of steps and devices.

Moreover, the alignment of the semiconductor wafer is performed at the initial stage or the final stage of each process, that is, when the semiconductor wafer is taken out from the storage carrier or when the semiconductor wafer which has been subjected to a predetermined process is returned to the storage carrier or during transfer.
Since it can be performed by the semiconductor wafer holding hand that takes out and returns to the storage carrier, the time required only for aligning the semiconductor wafer becomes unnecessary, and the processing time of the semiconductor manufacturing process can be shortened accordingly.
Furthermore, since the number of times the semiconductor wafer is taken out from the storage carrier can be reduced, dust adhesion can be considerably reduced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the semiconductor wafer holding hand of the present invention will be described below with reference to the embodiments shown in the accompanying drawings.

First, an example of a storage carrier in which semiconductor wafers and a large number of semiconductor wafers are stored in a hierarchical manner will be described.

Reference numeral 1 denotes a semiconductor wafer having a substantially disk shape (see FIG. 1,
3 and 4, etc.) and is formed by, for example, slicing a cylindrical silicon crystal body having a diameter of about 6 inches to 8 inches in a direction orthogonal to its axial direction, and for example, 0.5. Has a thickness of about 0.8 mm,
A linear orientation flat 2 is formed on a part of the peripheral portion.

The semiconductor wafer 1 as described above is subjected to various kinds of processing in the semiconductor manufacturing process, that is, surface polishing, epitaxial growth, oxidation, pattern formation, brobbing, and the like, and then a predetermined size. And then a large number of IC chips are formed.

Reference numeral 3 denotes a storage carrier (see FIGS. 1, 3 and 4) for storing a large number of semiconductor wafers 1, 1 ,. The transportation between the above-mentioned processing steps is performed in a state of being stored in the storage carrier 3.

The storage carrier 3 has a substantially box shape with both front and rear sides open, and both left and right side walls 4, 4 facing each other in parallel.
And a top plate 5 connecting the middle parts of the upper edges of the left and right side walls 4, 4 and a bottom plate 6 connecting the rear parts of the lower edges of the side walls 4, 4 integrally by a synthetic resin. It is formed.

.. are grooves formed in the surfaces of the side walls 4 and 4 facing each other and having a substantially lateral V-shape, and the grooves 7, 7 ,. Formed in the orientation
Further, they are arranged at a constant pitch in the up-down direction, whereby a shelf 8 is formed between each groove 7 and 7.

The arrangement pitch of the grooves 7, 7, ... In the vertical direction is, for example, about 5 mm.

The semiconductor wafer 1 has a pair of left and right portions in which two portions, which are located on the opposite sides of the center of the semiconductor wafer 1 on both sides of the center of the semiconductor wafer 1, are separately placed in the two left and right grooves 7 and 7 at the same height. It is placed on the shelves 8, 8 in a bridge form.
A large number of semiconductor wafers 1, 1, ... Are stored in a storage carrier 3 in a layered manner at a constant array pitch.

Reference numeral 9 denotes a semiconductor wafer holding hand for taking out and storing the semiconductor wafers 1, 1, ... With respect to the storage carrier 3, and the semiconductor wafer holding hand 9 has a circumference of the semiconductor wafer 1 as described later. It also has a directional alignment function.

Reference numeral 10 denotes a base plate of the semiconductor wafer holding hand 9, which is a flat plate having a width approximately half the diameter of the semiconductor wafer 1 and a length approximately 1.5 times the diameter of the semiconductor wafer 1. The front edge 10a is formed in a semi-circular shape, and a relatively thin disc-shaped protrusion is formed at the front end of the upper surface and substantially at the center of the circle along the front edge 10a. A portion 11 and a cylindrical joint portion 12 are provided at the base end so as to project.

Incidentally, such a base plate 10 is integrally formed of a ceramic material.

Reference numeral 13 denotes a shallow recess formed on the lower surface of the base plate 10, the tip of which is below the portion where the projection 11 is formed, and the base end of which is the portion where the joint portion 12 is formed. The cutout edges 13a are formed so as to reach the lower side, respectively, and a cutout edge 13a directed downward and inward is formed on the peripheral edge of the opening.

Reference numeral 14 is a cover plate for covering the recess 13, and the cover plate 14 is fixed to the base plate 10 in a state of being fitted almost exactly to the notched edge 13a, whereby the base plate 1 is formed.
A thin space 15 (hereinafter, referred to as “intake space”) that is closed at the bottom of 0 is defined.

Reference numeral 11a is an intake hole formed in the center of the projection 11, and the lower end thereof is opened in the intake space 15.

Further, the lower end of the hole 12a of the joint portion 12 is opened to the intake space 15, and the upper half portion thereof is formed as a screw hole.

Reference numeral 16 is a bearing fixed to the protrusion 11 in an externally fitted shape.

Reference numeral 17 is a disc-shaped turntable, the diameter of the upper half 17a of which is smaller than the width of the base plate 10 and the diameter of the lower half 17b of which is one turn smaller than the diameter of the upper half 17a. The lower half portion 17b (hereinafter, referred to as "driven pulley") is small in size and has a wall thickness of the protrusion 1 described above.
It is formed to be slightly smaller than the protruding amount of the first base plate 10 from the upper surface, and a belt winding groove 18 is formed on the outer peripheral surface thereof.

Numeral 19 is a hole formed in the center of the turntable 17, and the inner diameter of the upper half portion 19a of the hole 19 is one size smaller than the outer diameter of the lower half portion 17b of the turntable 17, and the lower half. The inner diameter of the portion 19b is formed to be substantially the same as the outer diameter of the bearing 16.

The lower half 19b of the hole 19 of the turntable 17 is fitted onto the bearing 16 so that the turntable 17 is rotatably supported by the protrusion 11 of the base plate 10 through the bearing 16. .

Reference numeral 20 denotes a disc-shaped holding plate having an outer diameter slightly smaller than the inner diameter of the upper half portion 19a of the hole 19 of the turntable 17 and having a wall thickness smaller than the height of the upper half portion 19a. The turntable 17 is small and is fixed to the upper surface of the projection 11 by screwing or the like while being positioned in the upper half portion 19a of the hole 19, so that the turntable 17 moves upward from the projection 11 of the base plate 10. It is prevented from coming off.

A hole 20a is formed at the center of the holding plate 20, and the intake hole 11 formed in the protrusion 11 is formed.
a is opened upward through this hole 20a.

Reference numeral 21 denotes an intake hole 11 on the upper end surface of the projection 11.
An O-ring fitted in an annular groove 11b formed so as to surround a, and the O-ring 21 is in close contact with the lower surface of the holding plate 20 when the holding plate 20 is attached to the upper end surface of the protrusion 11. To do.

Numerals 22, 22, ... Are upper surfaces of the base plate 10 on the joint portion 12 side, and are columns (see FIG. 5) projecting upward at a position closer to the center than the joint portion 12. ,
A motor support plate 23 is fixed so as to bridge the upper ends of the columns 22, 22, ....

Reference numeral 24 is a stepping motor fixed to the upper surface of the motor support plate 23. A rotary shaft 24a protruding downward from the casing thereof penetrates the motor support plate 23 and has a drive pulley 25 at its lower end. It is fixed.

The stepping motor 24 is used as the motor support plate 2
In the state of being supported by the columns 22, 22, ... Of the base plate 10 via the belt 3, the belt winding groove 25a formed in the belt winding groove 25a of the drive pulley 25 and the driven pulley 17b of the turntable 17 is formed. And are located at approximately the same height,
An endless belt 26 is provided between the pulleys 25 and 17b.
Has been bridged.

When the stepping motor 24 rotates, the drive pulley 25-belt 26-driven pulley 17b.
The rotation is transmitted, and the turntable 17 is rotated.

Reference numeral 27 is an air hose, and a pipe joint 28 screwed to the joint portion 12 is attached to one end of the air hose.
The air hose 27 is connected to the joint portion 12 via a pipe joint 28, and the other end thereof is connected to the intake port of the air suction device via a fluid valve (not shown).

When the air is sucked by the air suction device, the air in the air hose 28, the air intake space 15 and the air intake hole 11a communicating with the air is sucked in, and the vicinity of the upper surface of the hole 19 of the turntable 17 is negatively pressurized. To be

Reference numeral 29 is a flat box-shaped cover having an open lower surface, and the cover 29 is formed so that the shape viewed from above is substantially the same as the shape of the base plate 10 and the length of the cover 29 is long. The base end side portion 29a from the position close to the base end to the base end edge in the depth direction is the remaining tip end side portion 2a.
It projects upward so as to have a height approximately twice that of 9b.

29c, 29d, and 29e are the above-mentioned covers 29
Is formed on the upper surface of the cover 29. The hole 29c is formed so that the upper half portion 17a of the turntable 17 projects slightly upward from the upper surface of the cover 29, the hole 29d is formed so that the stepping motor 24 is arranged, and the hole 29e is formed The pipe joint 28 is formed so as to protrude from the upper surface of the cover 29.

Reference numeral 29f denotes a tip side portion 29 of the cover 29.
b is a sensor arrangement hole formed at the base end portion, and the sensor arrangement hole 29f has a convex shape when viewed from above, and the convex upper protruding portion is formed so as to face the tip, The upper protruding portion is a light passage hole 29g as described later.

Reference numeral 30 denotes a guide plate placed on the cover 29 so as to substantially cover a portion of the sensor placement hole 29f other than the light passage hole 29g, and the width of the guide plate 30 is equal to that of the base plate 10. The width 30 is substantially the same as the width and has a substantially rectangular shape when viewed from above, and a side 30a (hereinafter referred to as a "guide portion") facing the tip side has a curvature substantially the same as the circumference of the semiconductor wafer 1 and The turntable 17 is formed in an arc shape centered on the center of the turntable 17 and has a wall thickness of the semiconductor wafer 1
Is thicker than the wall thickness of.

Reference numeral 31 denotes the cover 2 of the upper surface of the base plate 10.
9 is a sensor support member fixed to a portion facing the sensor placement hole 29f, and an optical sensor 32 (only the tip is shown in the drawing) is supported by the sensor support member 31.

The sensor portion 32a located at the tip of the optical sensor 32 has a light passage hole 29 of the sensor arrangement hole 29f.
g of the optical sensor 32. Therefore, most of the optical sensor 32 is covered with the guide plate 30.
Only the tip portion including the sensor portion 32a has a light passage hole 29g.
Overlooking through.

The semiconductor wafer holding hand 9 is constructed as described above, and the thickness of the portion of the guide plate 30 from the guide portion 30a to the front end side (hereinafter referred to as "hand portion") is within the storage carrier 3. The stored semiconductor wafers 1, 1, ...
It is formed thinner than the space between the two semiconductor wafers 1 adjacent to each other in the upper and lower sides of.

Reference numeral 33 is, for example, the tip of an arm of a multi-arm robot, and the semiconductor wafer holding hand 9 is fixed in the horizontal direction by the robot by fixing the base end side portion of the base plate 10 to the tip 33 of the arm. And is supported so as to be vertically movable.

Therefore, the semiconductor wafer holding hand 9 takes out and stores the semiconductor wafer 1 from the storage carrier 3 and aligns the semiconductor wafer 1 in the following manner.

When the semiconductor wafer 1 stored in the storage carrier 3 is to be taken out, the semiconductor wafer holding hand 9 is first positioned in front of the storage carrier 3 as shown in FIG. By moving it between the wafer 1 and the semiconductor wafer 1 located below it,
From that state, as shown in FIGS. 3 and 4, the hand portion of the semiconductor wafer holding hand 9 is inserted into the storage carrier 3.

The insertion of the hand portion of the semiconductor wafer holding hand 9 into the storage carrier 3 is performed by the guide portion 30 of the guide plate 30.
The process ends when a comes into contact with the outer peripheral edge of the semiconductor wafer 1.

As a result, the turntable 17 is positioned below the semiconductor wafer 1 and coaxial therewith.

Next, the semiconductor wafer holding hand 9 is moved upwards and the semiconductor wafer 1 is relatively placed on the turntable 17.

At about the same time, the intake of air into the intake space 15 is started to turn the semiconductor wafer 1 into a turntable 1.
Adsorb and hold at 7.

In this state, the semiconductor wafer 1 is in a state in which both sides of the semiconductor wafer 1 are separated from the shelves 8, 8 of the storage carrier 3 in a slightly upward direction, so that the semiconductor wafer holding hand 9 is retracted from the storage carrier 3. As a result, the semiconductor wafer 1 is taken out from the storage carrier 3.

When the semiconductor wafer 1 is stored in the storage carrier 3, the semiconductor wafer holding hand 9 holding the semiconductor wafer 1 is first moved to a position in front of the storage carrier 3 and the semiconductor wafer being held is held. 1 is moved to a height corresponding to the pair of left and right grooves 7, 7 in which the semiconductor wafer holding hand 9 is to be stored, and the hand portion of the semiconductor wafer holding hand 9 is inserted into the storage carrier 3 from that state.

Next, after the intake of air into the intake space 15 is stopped, the semiconductor wafer holding hand 9 is lowered slightly to bring the semiconductor wafer 1 into a pair of left and right shelves 8 and 8 located below the grooves 7 and 7. Place on top.

In order to align the semiconductor wafer 1 in the circumferential direction, the turntable 17 is rotated while the semiconductor wafer 1 is adsorbed and held by the turntable 17, and the presence or absence of the orientation flat 2 is detected. By controlling the position of the turntable 17.

An example of such a positioning operation will be described below with reference to FIGS. 7 to 9.

When aligning the semiconductor wafer 1, first, the turntable 17 is rotated to rotate the semiconductor wafer 1, and at the same time, detection light is emitted from the optical sensor 32.

Then, the semiconductor wafer 1 on the turntable 17 has its orientation flat 2 as shown in FIG. 7, for example.
While the optical sensor 32 is at a position not facing the sensor portion 32a of the optical sensor 32, the detection light emitted from the optical sensor 32 is reflected by the semiconductor wafer 1 and a part of the detection light becomes return light. The light is received by the light receiving portion, and as a result, the optical sensor 32 has a portion other than the orientation flat 2 in the sensor portion 32a.
It is detected that it is facing.

When the semiconductor wafer 1 is rotated, the
As shown in FIG. 1, one end of the orientation flat 2 has an optical sensor 3
When the optical sensor 32 comes to a position facing the second sensor portion 32a, it is emitted upward without being reflected by the semiconductor wafer 1. Therefore, the optical sensor 32 has one end in the circumferential direction of the orientation flat 2 of the semiconductor wafer 1. Detects that the section is located.

When the semiconductor wafer 1 is further rotated and the other end of the orientation flat 2 of the semiconductor wafer 1 comes to a position facing the sensor portion 32a of the optical sensor 32 as shown in FIG. Since a part of the light is returned to the light receiving portion of the optical sensor 32, the optical sensor 32 detects that the other end of the semiconductor wafer 1 in the circumferential direction of the orientation flat 2 is positioned.

In this way, the semiconductor wafer holding hand 9 can detect the position of the orientation flat 2 of the held semiconductor wafer 1, and further, by rotating the stepping motor 24 at a predetermined rotation angle, The orientation flat 2 of the semiconductor wafer 1 can be oriented in a predetermined direction, that is, the semiconductor wafer 1 can be aligned.

Incidentally, such alignment can be performed outside the storage carrier 3 or anywhere inside it.

[0065]

As is apparent from the above description, the semiconductor wafer holding hand of the present invention inserts / removes semiconductor wafers stored in a storage carrier that stores a plurality of semiconductor wafers in a hierarchical manner at a predetermined pitch. A semiconductor wafer holding hand, which is housed in the housing carrier and has a thickness smaller than a space between vertically adjacent semiconductor wafers, and a hand portion rotatably supported by the tip portion of the hand portion, the upper surface of which is A turntable positioned so as to project slightly from the upper surface of the hand portion, a drive means for rotating the turntable, and a notch edge (orientation flat) formed on the peripheral portion of the semiconductor wafer mounted on the turntable are detected. And an orientation flat detecting means for performing the orientation flat detection.

Therefore, the semiconductor wafer holding hand of the present invention has, in addition to its original function of holding a semiconductor wafer,
It also has the function of aligning the semiconductor wafer.
The semiconductor wafer can be aligned on the semiconductor wafer holding hand, and it is not necessary to provide a dedicated alignment device for aligning the semiconductor wafer in the semiconductor wafer transfer system. The size can be reduced, and the number of steps and devices dedicated to alignment can be reduced.

Moreover, the alignment of the semiconductor wafer is performed at the initial stage or the final stage of each process, that is, when the semiconductor wafer is taken out from the storage carrier or when the semiconductor wafer which has been subjected to a predetermined process is returned to the storage carrier or during transfer.
Since it can be performed by the semiconductor wafer holding hand that takes out and returns to the storage carrier, the time required only for aligning the semiconductor wafer becomes unnecessary, and the processing time of the semiconductor manufacturing process can be shortened accordingly.
Furthermore, since the number of times the semiconductor wafer is taken out from the storage carrier can be reduced, dust adhesion can be considerably reduced.

In the above embodiment, the semiconductor wafer placed on the turntable is sucked and held on the turntable by the air suction means. However, by doing so, the semiconductor wafer is held and positioned. The alignment can be performed reliably.

Further, the concrete shape or structure shown in the above embodiment is only one example for carrying out the semiconductor wafer holding hand of the present invention,
The technical scope of the present invention should not be limitedly interpreted by these.

[Brief description of drawings]

1 to 9 show an example of an embodiment of a semiconductor wafer holding hand of the present invention, and FIG. 1 is a perspective view showing a semiconductor wafer holding hand and a storage carrier.

FIG. 2 is an enlarged perspective view showing a state in which a cover is partially cut away and a turntable is disassembled.

FIG. 3 is a plan view showing a state in which a hand portion of a semiconductor wafer holding hand is inserted into a storage carrier.

FIG. 4 is a side view showing a state in which a hand portion of a semiconductor wafer holding hand is inserted into a storage carrier.

FIG. 5 is an enlarged side view of a main part with a part cut away.

FIG. 6 is an enlarged side view of another main part with a part cut away.

7 to 9 show an example of an orientation flat detection operation for aligning a semiconductor wafer with time, and FIG. 7 is an enlarged plan view of a main part showing an initial state.

FIG. 8 is an enlarged plan view of an essential part showing a state in the middle of the orientation flat detection operation.

FIG. 9 is an enlarged plan view of the essential parts showing the state at the end of the orientation flat detection operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 semiconductor wafer 2 notch edge (orientation flat) 3 storage carrier 9 semiconductor wafer holding hand 10a, 17, 29b hand part 17 turntable 24, 25, 26 drive means 32 orientation flat detection means

Claims (1)

[Claims] 1. A semiconductor wafer holding hand for inserting and removing semiconductor wafers stored in a storage carrier that stores a plurality of semiconductor wafers hierarchically at a predetermined pitch, wherein the semiconductor wafers are stored in the storage carrier and vertically adjacent to each other. A hand portion having a thickness smaller than the distance between the wafers, a turntable rotatably supported by the tip of the hand portion, and an upper surface of which is slightly protruding from the upper surface of the hand portion, and the turntable. A semiconductor wafer holding hand, comprising: a rotating means for rotating the rotating table; and an orientation flat detecting means for detecting a notch edge (orientation flat) formed on a peripheral portion of the semiconductor wafer placed on the turntable.