Treatment object conveyor apparatus, semiconductor manufacturing apparatus, and treatment object treatment method

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a treatment object conveyor apparatus for conveying objects to be treated inside a chamber, a semiconductor manufacturing apparatus comprising the treatment object conveyor apparatus, and a treatment object treatment method that uses the semiconductor manufacturing apparatus.

2. Description of the Related Art

In FIG.

8

A-

FIG. 8D

are diagrammed a treatment object conveyor apparatus for conveying objects to be treated, which configures a main component of a conventional semiconductor manufacturing apparatus. A vacuum chamber comprises an upright vacuum chamber

1

, and, above and below, two connecting chambers

2

and

3

that are connected laterally, so that a treatment object

4

such as a semiconductor wafer or a wafer cassette for holding semiconductor wafers can be conveyed between the vacuum chamber

1

and the connecting chambers

2

and

3

.

FIG. 8A

is a front elevation diagramming how conveying is done in the horizontal direction indicated by arrow B between the vacuum chamber

1

and the upper connecting chamber

2

.

FIG. 8B

is a side elevation of FIG.

8

A.

FIG. 8C

is a front elevation diagramming how conveying is done in the vertical direction indicated by arrow A inside the vacuum chamber

1

. And

FIG. 8D

is a front elevation diagramming how conveying is done in the horizontal direction indicated by arrow B between the vacuum chamber

1

and the lower connecting chamber

3

.

An elevator mechanism

16

that raises and lowers a treatment object conveyor robot

12

is deployed inside the vacuum chamber

1

. To describe the configuration of this elevator mechanism

16

, a straight guide shaft

7

and a threaded shaft

6

are deployed upright between two elevator attachment bases

5

and

6

located at the top and bottom inside the vacuum chamber

1

. To the threaded shaft

8

is attached an elevator pedestal

9

that ascends and descends along the guide shaft

7

. For this reason, a threaded hole that engages the threaded shaft

8

and a guide hole in which the guide shaft

7

can slide are provided in the elevator pedestal

9

. By engaging the elevator pedestal

9

with the threaded shaft

8

and turning the threaded shaft

8

, the elevator pedestal

9

is made to ascend and descend along the guide shaft

7

. A motor

10

that is designed for operation in air and that is the drive source for turning the threaded shaft

8

is provided in the atmosphere outside the vacuum chamber

1

. This is because motors designed for use in a vacuum are expensive. The turning shaft of the motor

10

penetrates to the inside of the vacuum chamber

1

via a magnetic seal

11

, and is linked to the threaded shaft

8

through the elevator attachment base

5

, so that the turning thereof is transmitted to the threaded shaft

8

.

With only the elevator pedestal

9

, the treatment object

4

can only be made to ascend and descend in the vertical direction (arrow A), wherefore the elevator pedestal

9

is linked to a treatment object conveyor robot

12

to achieve complex movements of the treatment object

4

that include movements in the horizontal direction (arrow B). The treatment object conveyor robot

12

comprises a conveyor arm

13

and a drive unit

14

comprising a motor. The conveyor arm

13

is turned or extended and retracted by the drive unit

14

to convey the wafer-holding wafer cassette or other treatment object

4

in the horizontal direction.

Unless the entire treatment object conveyor robot

12

is made to ascend and descend, it is possible to place the drive unit for the treatment object conveyor robot

12

outside of the vacuum chamber

1

. However, in order to cause the entire treatment object conveyor robot

12

to ascend and descend, the drive unit

14

is accommodated inside an airtight vessel

15

from which communication with the outside has been cut off, thus preventing dust generated in conjunction with the movement of the drive unit

14

from being scattered inside the vacuum chamber

1

. For the same reason as that stated earlier, designing the drive unit

14

to operate in a vacuum results in high cost, wherefore an inexpensive drive unit designed for use in air is used, with the interior of the airtight vessel

15

normally at atmospheric pressure.

The treatment object conveyor apparatus described in the foregoing is subject, however, to the following problems.

(1) The elevator mechanism comprising such sliding parts as the guide shaft

7

, threaded shaft

8

, and elevator pedestal

9

, etc., is deployed inside the vacuum chamber

1

, wherefore particles and the like are produced by the sliding parts and not only constitute a danger of contaminating the clean environment inside the vacuum chamber

1

but also result in a larger vacuum chamber

1

because the elevator mechanism

16

is inside the vacuum chamber

1

.

(2) The drive unit

14

inside the airtight vessel

15

linked to the elevator pedestal

9

is designed for operation in air, wherefore, if a leak develops in the airtight vessel

15

so that the interior thereof becomes a vacuum as inside the vacuum chamber

1

, there is a danger that the drive unit

14

which is designed for operation in air will be damaged so that stable operation cannot be obtained. In order to prevent this, the drive unit

14

must be designed to operate in a vacuum, which makes it expensive.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a treatment object conveyor apparatus, a semiconductor manufacturing apparatus, and a treatment object treatment method wherewith it is possible to stably operate the treatment object conveyor means deployed inside a chamber, and wherewith the problems in the prior art noted above are resolved. Another object of the present invention is to provide a treatment object conveyor apparatus, a semiconductor manufacturing apparatus, and a treatment object treatment method wherewith the generation of dust inside the chamber can be reduced and the chamber can be made smaller.

A first invention is a treatment object conveyor apparatus comprising: a chamber; a treatment object conveyor means deployed inside the chamber having a conveyor unit and a drive unit for driving the conveyor unit, for driving the conveyor unit with the drive unit and for conveying the treatment object carried by the conveyor unit; an airtight vessel for housing the drive unit of the treatment object conveyor means in an airtight condition inside the chamber; a shaft that penetrates in an airtight way into the chamber from outside the chamber and which is linked with the airtight vessel for advancing and retracting the airtight vessel relative to the chamber to move the entirety of the treatment object conveyor means; a movement mechanism for advancing and retracting the shaft; and a venting channel that effects the outside atmosphere inside the airtight vessel by causing the airtight vessel to communicate with the outside of the chamber. The pressure inside the chamber may be a vacuum, atmospheric pressure, or some other pressure.

When the movement mechanism deployed outside the chamber is moved, the airtight vessel accommodated inside the chamber is moved via the shaft, wherefore the entirety of the treatment object conveyor means attached to the airtight vessel also moves. The drive unit inside the airtight vessel can be moved in the outside atmosphere because the airtight vessel communicates to the outside. When the drive unit is moved, the treatment object conveyor means themselves move, and the treatment object carried on the conveyor unit is conveyed to another location inside the chamber, or to a connecting chamber connected to the chamber.

Of the components of the treatment object conveyor means deployed inside the chamber, the conveyor unit is exposed inside the chamber, but the drive unit is configured so that it is contained in an airtight condition in the airtight vessel that communicates with the outside. That being so, even when the treatment object conveyor means are operated inside the chamber, unlike the conveyor unit that is exposed to the chamber atmosphere, the drive unit is not exposed to the chamber atmosphere. Also, the airtight vessel communicates with the outside, wherefore, even should the airtightness of the airtight vessel fail, the interior of the chamber will merely become the outside atmosphere, and no change will occur in the atmosphere inside the airtight vessel, so that the drive unit will not malfunction because of the airtightness failure.

Furthermore, because the movement mechanism is deployed outside the chamber, the dust produced during the movement of the movement mechanism is not produced inside the chamber, and the cleanness of the chamber is improved. Also, because there is no need to accommodate the movement mechanism inside the chamber, the chamber can be made smaller, and the cost of the apparatus reduced.

A second invention is the treatment object conveyor apparatus according to the first invention, wherein the venting channel comprises a supply/exhaust channel for supplying and exhausting an inert gas, atmospheric air, or a mixture of such gases from outside the chamber to and from the airtight vessel.

Instead of simply introducing the outside atmosphere into the airtight vessel, a supply/discharge channel is actively deployed in the venting channel, so that, if an inert or inactive gas such as nitrogen, helium, or argon, or atmospheric air, or a mixture of such gases is supplied to the interior of the airtight vessel, the motor, etc., of the drive unit configuring the treatment object conveyor means accommodated inside the vacuum vessel can be cooled, and the useful life of the drive unit extended. Also, the gas supplied to the interior of the airtight vessel is exhausted after circulating inside the airtight vessel, wherefore contaminating substances generated by the drive unit can be removed from the interior of the airtight vessel. Therefore, even should the airtightness of the airtight vessel fail, the volume of contamination entering the chamber can be reduced.

A third invention is the treatment object conveyor apparatus according to the second invention, wherein electrical wiring is passed to the drive unit accommodated inside the airtight vessel from outside the chamber through the venting channel provided in the shaft. Thus by implementing a simple structure that uses the venting channel provided in the shaft, it is possible to connect the necessary signal lines and power supply lines, etc., to the drive unit.

A fourth invention is the treatment object conveyor apparatus according to the first to third inventions, wherein the shaft is covered by a bellows, the starting end of the bellows is secured to the chamber by sealing means such as an O ring, the terminal end of the bellows is secured to the movement mechanism by sealing means such as an O ring, and the chamber into which the shaft is inserted is made an airtight structure. The seals between the shaft and the chamber, and between the shaft and the movement mechanism, can be secured easily and at low cost by sealing means comprising an O ring or the like, and the sealing of the shaft with respect to movement in the axial direction can be secured easily and at low cost by the bellows. Instead of O rings, the sealing means may be Teflon rings or elastomer gaskets.

A fifth invention is the treatment object conveyor apparatus according to the first to fourth inventions, wherein the treatment object is a semiconductor wafer, a glass substrate, or a cassette for accommodating such. The treatment object conveyor means in this invention is particularly suitable for use when the treatment object is a semiconductor wafer, a glass substrate, or a cassette for accommodating such.

In a sixth invention, the drive unit is accommodated inside the airtight vessel that communicates with the outside, and the drive unit does not need to be designed for operation in a vacuum, even if the treatment object conveyor means are operated inside the vacuum chamber. Also, because the airtight vessel in this embodiment communicates with the outside, even if the airtightness of the airtight vessel fails, all that will happen is that the interior of the chamber will become the outside atmosphere, and the airtight vessel will continue unaltered with the outside atmosphere intact, wherefore this will not cause drive unit malfunction.

In a seventh invention, the interior of the chamber in the first to the fifth inventions is put at atmospheric pressure. When the pressure inside the chamber is made atmospheric pressure, the interior of the chamber will not be contaminated by dust generated by the drive unit, the drive unit can be cooled by connecting it to the outside air, and, if an inert or inactive gas is supplied, the drive unit cooling effectiveness will be improved.

An eighth invention is a semiconductor manufacturing apparatus comprising the treatment object conveyor apparatus of the first to the seventh inventions. By building the treatment object conveyor apparatus described in the foregoing into a semiconductor manufacturing apparatus, a more highly reliable semiconductor manufacturing apparatus is obtained.

A ninth invention uses a semiconductor manufacturing apparatus comprising a chamber; a treatment subchamber for treating treatment objects that is linked in an airtight manner to the chamber; a treatment object conveyor means, deployed inside the chamber, comprising an arm unit and a drive unit for driving the arm unit, which drives the arm unit with the drive unit and conveys the treatment object carried by the arm unit; an airtight vessel for accommodating the drive unit of the treatment object conveyor means in an airtight manner inside the chamber; a venting channel that allows the airtight vessel to communicate with the outside of the chamber; and a shaft that penetrates in an airtight manner into the chamber from outside the chamber and which is linked with the airtight vessel for advancing and retracting the airtight vessel relatively with the chamber to move the treatment object conveyor means inside the chamber.

Further provided and disclosed is a treatment object treatment method wherein, having introduced the outside atmosphere into the airtight vessel through the venting channel, the shaft is advanced and retracted to integrally move the treatment object conveyor means to positions corresponding to the treatment subchamber inside the chamber, after which the arm unit of the treatment object conveyor means is moped by the drive unit accommodated inside the airtight vessel, the treatment object carried by the arm unit is conveyed from the chamber to the treatment subchamber, the treatment object conveyed to the treatment subchamber is loaded on a treatment object carrier unit inside the treatment subchamber, and the treatment object loaded on the treatment object carrier unit is subjected to a prescribed treatment.

The airtight vessel is made to communicate with the outside, wherefore, when a vacuum exists in the chamber, the airtight vessel merely becomes the outside atmosphere, making it unnecessary to design the drive unit for operation in a vacuum. The drive unit will not be damaged by a failure of airtightness in the airtight vessel, so the process of treating the treatment object need not be suspended midway, wherefore the treatment object production cost can be reduced. Also, when an airtightness failure does occur in the airtight vessel, maintenance may be done at a time other than during a treatment process. Furthermore, whether the chamber is made a vacuum or kept at atmospheric pressure, the drive unit is accommodated in the airtight vessel, wherefore the interior of the chamber is not contaminated by dust, and the treatment object being treated can be maintained in a clean state. Furthermore, whether the chamber is made a vacuum or kept at atmospheric pressure, the airtight vessel communicates with the outside of the chamber, wherefore the drive unit is cooled so that its useful life is extended, long-term operation of the treatment object conveyor means is facilitated, the frequency of stopping the processing of treating the treatment object midway is reduced, and the cost of producing the treatment object can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is a simplified configurational diagram of a treatment object conveyor apparatus according to a first embodiment;

FIG. 2

is a simplified configurational diagram of a treatment object conveyor apparatus according to a second embodiment;

FIG. 3

is a simplified configurational diagram of a treatment object conveyor apparatus according to a third embodiment;

FIG. 4

is a simplified configurational diagram of a treatment object conveyor apparatus according to a fourth embodiment;

FIG. 5

is a simplified configurational diagram of the cooling structure of a drive unit in the treatment object conveyor apparatus according to the fourth embodiment;

FIG. 6

is a cross-sectional view of the specific structure of the drive unit according to the fourth embodiment;

FIG. 7

is a simplified configurational diagram of a semiconductor manufacturing apparatus that is equipped with an embodied treatment object conveyor apparatus;

FIG.

8

A-

FIG. 8D

are a set of simplified configurational diagrams of a conventional treatment object conveyor apparatus, with

FIG. 8A

being a front elevation thereof when the treatment object is moved from the vacuum chamber to the upper connecting chamber, (b) being a side elevation of

FIG. 8A

,

FIG. 8C

being a front elevation thereof when the treatment object is raised or lowered inside the vacuum chamber, and

FIG. 8D

being a front elevation thereof when the treatment object is moved from the vacuum chamber to the lower connecting chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the treatment object conveyor apparatus, semiconductor manufacturing apparatus, and treatment object treatment method of the present invention are now described.

In

FIG. 1

is diagrammed a first embodiment wherein an elevator mechanism

30

is deployed outside a vacuum chamber

21

as a movement mechanism. A treatment object conveyor robot

32

is deployed inside the vacuum chamber

21

for handling a treatment object

24

such as a substrate or wafer cassette. Connecting chambers

22

and

23

are connected laterally, above and below, to the vacuum chamber

21

, so that the treatment object

24

can be conveyed by the treatment object conveyor robot

32

between the vacuum chamber

21

and the connecting chambers

22

and

23

. Elevator attachment bases

25

and

26

, a guide shaft (not shown), a threaded shaft

28

, and an elevator pedestal

29

attached thereto, which configure the elevator mechanism

30

that raises and lowers the treatment object conveyor robot

32

, are located outside the vacuum chamber

21

in the same manner as a motor

20

for turning the threaded shaft.

The treatment object conveyor robot

32

comprises a conveyor arm

33

for conveying the treatment object

24

and a drive unit

34

for driving the conveyor arm

33

. The drive unit

34

is accommodated inside an airtight vessel

35

. This treatment object conveyor robot

32

and a support member

41

attached to the elevator pedestal

29

are linked by a shaft

42

that penetrates inside the vacuum chamber

21

so that it can be freely advanced and retracted, and the ascending and descending movement of the elevator pedestal

29

resulting from the turning of the threaded shaft

29

linked to the motor

20

is transmitted to the treatment object conveyor robot

32

inside the vacuum chamber

21

. The shaft

42

is made airtight with respect to the vacuum chamber

21

. This airtightness is secured by sealing means such as O rings

44

and a bellows

43

. The bellows

43

surrounds the shaft

42

. The upper end thereof is attached via one O ring

44

to the vacuum chamber

21

, while the lower end thereof is attached to the support member

41

for the elevator pedestal

29

via another O ring

44

. An O ring

44

is also provided at the connection between the shaft

42

and the support member

41

.

The shaft

42

and support member

41

are linked by a bolt

40

to prevent the shaft

42

from toppling over. Alternatively it may be connected by welding. In that case, the O ring

44

placed between the support member

41

and the shaft

42

to preserve airtightness becomes unnecessary. Stainless steel is used for the material of the bellows

43

in the interest of high pressure resistance and high heat resistance.

When the configuration is as described in the foregoing, the sliding parts such as the guide shaft, threaded shaft

28

, and elevator pedestal

29

are not located inside the vacuum chamber

21

, wherefore particles and the like caused by the sliding parts are not produced, and the clean environment inside the vacuum chamber

21

can be preserved. Also, because the elevator mechanism

30

is outside the chamber

21

, the vacuum chamber

21

can be made smaller.

The treatment object conveyor robot

32

deployed inside the vacuum chamber

21

must have electrical wiring led into the vacuum chamber

21

from the outside and connected to the drive unit

34

in order to drive and control the conveyor arm

33

. This wiring is led in by providing an airtight wiring access port in the vacuum chamber

21

. When this is done, however, the structure becomes complex. Therefore, as in the embodiment diagrammed in

FIG. 2

, the shaft

42

is given a hollow structure, the power lines, signal lines, and sensor lines (not shown), etc., necessary for controlling the drive unit

34

are led through a hollow portion

45

that serves as the venting channel, and the drive unit

34

is thus connected to external equipment, etc. The sensor lines are electrical wires that connect to sensors such as a treatment object detection sensor.

In the first and second embodiments described in the foregoing, a bellows

43

is used for securing the airtightness of the shaft

42

with respect to its movement in the axial direction. However, as in a third embodiment, diagrammed in

FIG. 3

, instead of using a bellows, a toppling-prevention guide

47

, such as a threaded spline that allows movement in the axial direction but restricts movement in directions around the shaft, may be attached in an airtight manner at the place where the shaft penetrates into the vacuum chamber

21

, a spline shaft passed through an insertion hole in the toppling-prevention guide

47

, and an O ring

46

set between the toppling-prevention guide

47

and the spline shaft

62

, and the airtightness relative to movement in the axial direction of the spline shaft

62

thus secured. When the airtight vessel is configured in this manner, with the toppling-prevention guide

47

and O ring

46

, airtightness can be secured with a simple structure that does not require a bellows, whereupon the treatment object conveyor robot

12

can ascend and descend smoothly.

The support of the shaft

42

for the vacuum chamber

21

is non-contact support as diagrammed in FIG.

1

and

FIG. 2

, but is contact-supported by the spline shaft

62

as diagrammed in FIG.

3

.

In the third embodiment described in the foregoing, however, although no mention was made of any problem with the airtight vessel provided inside the vacuum chamber

21

, when the interior of the airtight vessel

35

is put at atmospheric pressure, and the airtight vessel

35

is sectioned off from the outside as conventionally, if the airtightness of the airtight vessel

35

fails, the atmosphere in the airtight vessel

35

flows into the vacuum chamber

21

, whereupon the interior of the airtight vessel

35

becomes a vacuum, so that the drive unit

34

which is not designed for operation in a vacuum will be damaged, which constitutes a problem. That being so, in a fourth embodiment, that problem is resolved by having the interior of the airtight vessel

35

communicate with the outside. This is described specifically using FIG.

4

.

The airtight vessel

35

is deployed inside the vacuum chamber

21

where glass substrates, semiconductor wafers, or other treatment objects

24

are handled. On the outside of the airtight vessel

35

is attached the conveyor arm

33

that is turned, extended, and retracted by the drive, while on the inside is attached the drive unit

34

comprising the motor for driving the conveyor arm

33

, etc.

The elevator mechanism

30

that raises and lowers the airtight vessel

35

and raises and lowers the entire treatment object conveyor robot

32

is positioned outside the vacuum chamber

21

where the treatment object

24

is handled. As noted earlier, this elevator mechanism

30

comprises the motor

20

, elevator attachment bases

25

and

26

, guide shaft, threaded shaft

28

, elevator pedestal

29

, and support member

41

.

The shaft

42

that transmits the movement of the elevator mechanism

30

to the airtight vessel

35

inside the vacuum chamber

21

has its lower end linked in an airtight manner to the support member

41

of the elevator pedestal

29

, is passed in an airtight manner into the interior of the vacuum chamber

21

at the bottom thereof, and has its upper end linked in an airtight manner to the airtight vessel

35

. The airtightness between the airtight vessel

35

and the shaft

42

is secured by an O ring

44

or welding, etc. In order to maintain the airtightness of the vacuum chamber

21

while the shaft

42

is advancing and retracting, a pressure-resistant bellows

43

is deployed so as to surround the shaft

42

. The starting end side of the bellows is secured to the vacuum chamber

21

through an O ring

44

, and the terminal end side of the bellows is secured to the support member

41

of the elevator pedestal

29

through another O ring

44

.

The shaft

42

has a hollow structure. Through the hollow interior

45

thereof, the airtight vessel

35

is made to communicate with the outside of the vacuum chamber

21

, so that the interior of the airtight vessel

35

is always open to the outside atmosphere. Through the hollow shaft

42

are passed multiple electrical wires

48

, including sensor lines, which are necessary for controlling the treatment object conveyor robot

32

, from the outside of the vacuum chamber

21

to the drive unit

34

accommodated inside the airtight vessel

35

, thus securing control of the robot.

Because the airtight vessel

35

is opened in this manner to the outside through the shaft

42

, in a configuration wherein the drive unit

34

inside the airtight vessel

35

is always exposed to the outside atmosphere, the drive unit

34

will not be damaged even if the airtightness of the airtight vessel

35

fails, whereupon the drive unit

34

need not be designed for operation in a vacuum. Accordingly, the treatment object conveyor robot

32

deployed inside the vacuum chamber

21

can be operated stably. Also, with the shaft

42

given a hollow structure, the electrical wiring

48

needed for controlling the treatment object conveyor robot

32

can be run through the shaft

42

, wherefore there is no need to provide separate airtight wiring access ports in the vacuum chamber

21

, and the structure of the vacuum chamber

21

can be simplified. Also, the hollow portion

45

of the shaft

42

is used to configure a venting channel so that the airtight vessel

35

can communicate with the outside, wherefore it is not necessary to separately provide materials for securing this venting channel, so that configurational simplicity can be effected.

Furthermore, the drive unit

34

for driving the treatment object conveyor robot

32

, which constitutes a source of dust, is deployed in an airtight manner, covered by the airtight vessel

35

inside the vacuum chamber

21

, wherefore, unlike the case where the drive unit

34

is deployed so that it is completely exposed inside the vacuum chamber

21

, penetration of dust from the drive unit

34

, which constitutes a dust source, into the interior of the vacuum chamber

21

can be blocked, cleanness can be enhanced, and the reliability of the conveyor apparatus can be improved. In addition, because there is no need to provide space inside the vacuum chamber

21

for the elevator mechanism, the vacuum chamber

21

can be made smaller, and the cost of the vacuum chamber

21

reduced.

The cooling structure for the drive unit

34

is now described using FIG.

5

. Here, not only does the airtight vessel

35

that accommodates the drive unit

34

communicate with the outside air, but either an inert or inactive gas like nitrogen, helium, or argon, or air, or a gas mixture thereof is supplied to the interior of the airtight vessel

35

and exhausted from the airtight vessel

35

. A gas supply line

49

for supplying gas is passed through the hollow portion

45

of the shaft

42

, and led into the airtight vessel

35

, a gas supply port

50

is provided in the space inside the airtight vessel

35

to provide an opening therefor, and gas is supplied to the interior of the airtight vessel

35

. Alternatively, the gas supply line

49

is extended all the way to the drive unit

34

and connected to the drive unit

34

, a gas supply hole is provided in the space inside the drive unit

34

, and gas is supplied directly to the interior of the drive unit

34

. When the gas supply line

49

is connected to the drive unit

34

, a venting hole

39

is provided in the drive unit

34

for exhausting the gas supplied to the drive unit

34

to the outside of the drive unit

34

. The exhausting of the gas supplied into the airtight vessel

35

is facilitated by the remaining gap portion of the hollow portion

45

excluding the portion occupied by the gas supply line

49

. The supply/exhaust channel in the present invention is configured by the gas supply line

49

described here and the remaining gap portion of the hollow portion

45

.

When gas is supplied to the airtight vessel

35

, as compared to when the airtight vessel

35

is simply allowed to communicate with the outside air, the motor, etc., of the drive unit

34

for the treatment object conveyor robot

32

accommodated inside the airtight vessel

35

can be more effectively cooled. In this case, when gas is supplied all the way into the drive unit

34

, as compared to when the gas supply stops after entering the airtight vessel

35

, the drive unit

34

can be more effectively cooled, and the useful life of the drive unit

34

can be extended even further. Also, contaminants generated by the drive unit

34

can be eliminated, wherefore, even if the airtightness of the airtight vessel

35

should fail, the quantity of contamination entering the chamber

21

can be reduced. In this case, furthermore, the exhaust may be released directly into the outside air, or it may be conducted to an exhaust gas treatment system or the like in the factory.

Up to this point, no detailed description has been given of the drive unit

34

that drives the treatment object conveyor robot

32

. Such a detailed description is now given, taking as an example the double-shafted turning drive apparatus diagrammed in FIG.

6

.

A double-shafted turning drive apparatus

70

mainly comprises two motors

71

and

72

, and one container

80

that separately houses the two motors

71

and

72

. In order to allow the two motors

71

and

72

to communicate with the outside air, venting holes

83

,

84

, and

85

are provided, respectively, to the outer wall of a cylindrical first turning output shaft

73

that covers one motor

72

, to an inner wall

82

that partitions the interior of the container

80

into two compartments for separately accommodating the two motors

71

and

72

, and to the outer wall of the container

80

in that portion where the other motor

71

is accommodated. The container

80

that accommodates the motors

71

and

72

may also be directly configured by the airtight vessel

35

diagrammed in FIG.

4

.

Both the first drive motor

71

and the second drive motor

72

are configured by general-purpose motors. A first turning output shaft

73

is coaxially attached via a coupling

77

to the motor turning shaft

71

a

of the first drive motor

71

. The first turning output shaft

73

is formed so as to be hollow, the back part

73

b

in the axial direction near the first drive motor is closed, and the front part

73

a

far from the motor

71

side is opened, in a cylindrical shape. In the first turning output shaft

73

, the forward part

73

a

formed with a smaller diameter than the middle part and a projecting shaft

73

e

in the back part

73

b,

respectively, are supported so that they can turn freely, by the inner wall

82

, via turning-load-holding bearings

75

a

and

75

b.

The second drive motor

72

noted above is integrally attached inside the hollow cylindrical first turning output shaft

73

so that the motor turning shaft

72

a

thereof is formed coaxially with the first turning output shaft

73

. To the motor turning shaft

72

a

of this second drive motor

72

is coaxially attached the second turning output shaft

74

, via a coupling

78

. This second turning output shaft

74

is positioned coaxially with the first turning output shaft

73

so that it protrudes in the axial direction from the open front part

73

a

of the hollow cylindrical first turning output shaft

73

. The second turning output shaft

74

is supported so that it can turn freely by the inner wall of the open front part

73

a

via a bearing

75

c.

In the configuration described above, when the second drive motor

72

is stopped and held and the first drive motor

71

is driven, the hollow cylindrical first turning output shaft

73

turns. The second drive motor

72

is attached integrally inside the hollow cylindrical first turning output shaft

73

, wherefore the second turning motor

72

itself turns in conjunction with the turning of the first turning output shaft

73

. For this reason, the internal second turning output shaft

74

attached to the motor turning shaft

72

a

of the second turning motor

72

also turns. Thus, by driving only the first turning motor

71

in this manner, the second turning output shaft

74

can be synchronously turned with the first turning output shaft

73

.

Also, when the second turning motor

72

is driven and the first turning motor

71

is stopped and held, the external first turning output shaft

73

does not turn, and only the second turning output shaft

74

therein turns. Accordingly, the turning of the second turning output shaft

74

only can be secured.

Next, referring also to

FIG. 5

, the action of the conveyor arm

33

when the double-shafted turning drive apparatus

70

described in the foregoing is adopted as the drive unit

34

for the treatment object conveyor robot

32

is described.

(1) Stopping and holding the first drive motor

71

while driving the second turning motor

72

:

When the second turning motor

72

drives and the turning output shaft

74

thereof is turned counterclockwise, the first arm

33

a

in

FIG. 5

also turns counterclockwise, and, in conjunction with this turning, the second arm

33

b

turns clockwise. The treatment object carrier unit

33

c

is turned counterclockwise by the turning of the second arm

33

b

relative to the first arm

33

a.

As a result, the conveyor arm

33

conveys the treatment object

24

linearly in one direction.

(2) Stopping and holding the second turning motor

72

while driving the first turning motor

71

:

When the first turning output shaft

73

is turned by the first turning motor

71

, the second turning motor

72

held therein also turns together therewith. As a consequence, the conveyor arm

33

conveys the treatment object

24

in a turning motion in an attitude holding state with the first arm

33

a

and second arm

33

b

superimposed.

Thus, when the first turning motor

71

is stopped and held while the second turning motor

72

is driving, conveyance in one direction can be performed. If the second turning motor

72

is merely stopped and held, and a condition is brought about whereby only the first turning motor

71

drives, the treatment object

24

can be conveyed in a turning movement with the conveyor arm

33

in an attitude holding condition, without synchronizing the two drive motors.

In the configuration diagrammed in

FIG. 4

, however, the bellows

43

is positioned outside the vacuum chamber

21

. When such a configuration as this is implemented, and the interior of the vacuum chamber

21

is used in a vacuum state, the inside of the bellows

43

will become a vacuum, but, due to its structure, the bellows will not be readily deformed. Accordingly, it is preferable that the bellows

43

be positioned outside the vacuum chamber

21

. On the other hand, however, it is also possible, in principle, to deploy the bellows

43

inside the vacuum chamber

21

. In that case, the bellows would be deployed so as to surround that portion of the shaft

42

which penetrates into the interior of the vacuum chamber

21

, and the two bellows ends would be connected in an airtight manner to the airtight vessel

35

and to the vacuum chamber

21

. When the bellows

43

is positioned inside the vacuum chamber

21

in this manner, and the interior of the vacuum chamber

21

is used in a vacuum state, a vacuum will exist outside the bellows

43

, wherefore the bellows will be readily deformed due to its structure, and its strength cannot be preserved. In order to preserve its strength, reinforcement would be necessary, such as deploying guide rails along the direction of the extension and contraction of the bellows

43

. As a result, the number of parts would become greater, and manufacturing costs would become high. Accordingly, it is not desirable to deploy the bellows

43

inside the vacuum chamber

21

.

In the first to fourth embodiments described in the foregoing, the elevator pedestal

29

is raised and lowered by a motor

20

and threaded shaft

28

. This may be anything, however, so long as the configuration permits linear drive. The configuration may employ any of various cylinders or linear motors, for example.

It is also possible to configure a semiconductor manufacturing apparatus such as is diagrammed in

FIG. 7

using the treatment object conveyor apparatus described in the foregoing. In this semiconductor manufacturing apparatus, a load locking chamber

52

is deployed as a vacuum chamber below an upright reaction chamber

51

, and, in the interior of the load locking chamber

52

, a boat

53

is inserted into and withdrawn from the upright reaction chamber

51

as wafer carrier means for holding wafers W stacked in multiple stages below the upright reaction chamber

51

. Inside the load locking chamber

52

, a wafer transporter

54

is deployed as a treatment object conveyor robot for transporting the wafers W. This wafer transporter

54

carries the wafers W by performing complex movements by means of the elevator mechanism

55

deployed outside the load locking chamber

52

and a drive unit

56

that is housed inside an airtight vessel

57

that communicates with the outside and is maintained at atmospheric pressure.

The operation is now described. By the concerted movements of the wafer drive unit

56

and the elevator mechanism

55

, the wafer transporter

54

by which the wafers are held is aligned at the height position for wafer insertion into the boat

53

. The drive unit

56

of the wafer transporter

54

is driven so that a conveyor arm extends toward the boat

53

, and the wafer is conveyed to the carrying position in the boat

53

. The wafer transporter

54

is lowered with the elevator mechanism

55

by lowering the shaft a certain amount, and the wafer W is transferred to the wafer carrier unit of the boat

53

from the wafer transporter

54

. The drive unit

56

of the wafer transporter

54

is driven to contract the conveyor arm and return it to its original position. The drive unit

56

and the elevator mechanism

55

again work in concert to mote the wafer transporter

54

, and a wafer is extracted from a cassette (not shown) in which wafers are stacked and stored, adjacent to the load locking chamber

52

.

In order to extract a wafer from the cassette, the drive unit

56

and the elevator mechanism

55

work in concert to align the wafer transporter

54

at the cassette wafer extraction height. The drive unit

56

is driven, and the conveyor arm of the wafer transporter

54

is extended and inserted below a wafer. By raising the shaft a certain amount by the elevator mechanism

55

, the wafer transporter

54

is raised, and the wafer is transferred from the cassette on the conveyor arm. After this transfer, the conveyor arm of the wafer transporter

54

is contracted and returned to its original position.

By repeating the operation described in the foregoing, the desired number of wafers W are loaded into the boat

53

. After loading, the boat

53

is raised by a boat elevator (not shown) and inserted inside the reaction chamber

5

, whereupon the wafers W are subjected to a prescribed substrate treatment inside the reaction chamber

51

. Such treatment may include processing by a CVD method, processing to diffuse impurities, annealing processes, processing by a plasma CVD method, etching processes, ashing processes, or sputtering processes, etc. When the prescribed substrate treatment on the wafers W has been completed, the wafers W are conveyed out by a procedure that is the reverse of that of loading wafers into the boat

53

, as described above. Thus, if a semiconductor manufacturing apparatus is configured as diagrammed in

FIG. 7

using a treatment object conveyor apparatus, it becomes possible to build more highly reliable apparatuses.

In the embodiment described in the foregoing, the wafer carrier means comprise a boat

53

for carrying a plurality of wafers. The wafer carrier means, however, need not carry a plurality of wafers, but may carry only one wafer (single-wafer holding type). In the embodiment described in the foregoing, moreover, a boat is employed which is inserted inside the reaction chamber

51

after substrates have been loaded into the boat. However, the wafer carrier means such as the boat etc. may be permanently installed inside the reaction chamber

51

, a gate valve provided at the side of the reaction chamber

51

, and wafers W directly loaded into the reaction chamber

51

through the gate valve.

Moreover, the connecting chambers

22

and

23

described in the foregoing embodiments may be cassette chambers that accommodate cassette shelves, or they may be load locking chambers as described above. Nor do the chambers need to be limited to a vacuum state, but any atmosphere may be effected therein, and cases where N

2

replacement is performed are also permissible.

Furthermore, the pressure inside the chamber may be atmospheric pressure, in which case also the interior of the chamber will not be contaminated by dust produced by the drive unit. And, because the airtight vessel that accommodates the drive unit in an airtight fashion communicates with the outside air, the drive unit can be cooled. In addition, if an inert or inactive gas or the like is supplied into the airtight vessel, the effectiveness of cooling the drive unit can be enhanced.

As based on the present invention, the drive unit is accommodated in an airtight vessel, whereby the drive unit is removed from the atmosphere inside the chamber, so that the treatment object conveyor means deployed inside the chamber can be operated stably. Also, the airtight vessel in which the drive unit is accommodated communicates with the outside of the chamber, wherefore, irrespective of the atmosphere present inside the chamber, the outside atmosphere can be introduced into the airtight vessel, and the drive unit can be designed for operation at the pressure of the outside atmosphere. Moreover, because the elevator mechanism is deployed outside the chamber, the generation of dust inside the chamber is reduced, and the chamber can be made smaller. Especially in cases where the chamber is in a vacuum state, as compared to cases where the drive unit of the treatment object conveyor means is accommodated completely exposed inside the chamber, there is no need to design the drive unit for operation in a vacuum, and it can instead be designed for operation at atmospheric pressure, wherefore the apparatus can be given an inexpensive configuration.

Number	Date	Country	Kind
10-159117	Jun 1998	JP
11-146579	May 1999	JP

Number	Name	Date
5009738	Gruenwald et al.	Apr 1991
5121705	Sugino	Jun 1992
5643366	Somekh et al.	Jul 1997

Treatment object conveyor apparatus, semiconductor manufacturing apparatus, and treatment object treatment method

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (2)

US Referenced Citations (3)

Foreign Referenced Citations (1)