JPH0571136B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applied to semiconductor wafers (hereinafter referred to as wafers) in the manufacturing process of semiconductors such as integrated circuits.
The present invention relates to a plasma processing apparatus that performs plasma ashing processing, plasma etching processing, etc., and more specifically relates to a fully automatic plasma processing apparatus equipped with a mechanism for automatically transferring wafers from a wafer cassette to a wafer boat. teeth,
In addition to this plasma processing apparatus, the present invention can be widely applied to wafer processing apparatuses such as similar wafer heat treatment processes.

[Conventional technology]

In recent years, the semiconductor manufacturing process has shifted from the conventional wet process method to a dry process method. Among these dry process methods, the batch processing method using a barrel type (cylindrical chamber) is capable of processing a large number of semiconductors at once. It is widely used because it can process several wafers at the same time.

By the way, conventional barrel-type plasma processing apparatuses have a structure in which one chamber, which is a processing chamber, is provided in one processing apparatus.

[Problem that the invention seeks to solve]

Therefore, in order to increase production volume, it has been necessary to install these processing devices in a large number of clean rooms.

However, due to its purpose, clean rooms are extremely expensive to construct per unit space, and expanding the expensive clean room space to increase production increases product costs. The problem was that as the number of machines increased, the number of workers had to be increased, which also caused an increase in the cost of the product.

Furthermore, although the barrel type plasma processing apparatus has the great advantage of being able to simultaneously process a large number of wafers, it has the problem that when etching wafers with this processing apparatus, the uniformity of etching on the wafers is poor. With the recent increase in the degree of integration of circuits, it has become necessary to form increasingly finer patterns, and it has been desired to improve uniformity in batch processing type devices.

The present invention was made in view of these conventional problems, and its purpose is to increase the production of substrate processing per unit space without increasing the area occupied by processing equipment in an expensive clean room. It is an object of the present invention to provide a plasma processing apparatus which is excellent in economical efficiency and improves performance.

Another object of the present invention is to provide a plasma processing apparatus that can further improve the uniformity of wafer processing, has a high yield, and is highly productive.

[Means for solving problems]

In order to achieve this object, the present invention includes two horizontal tubular chambers, which are plasma processing chambers, arranged in upper and lower stages in the apparatus main body, and two horizontal tubular chambers, which are plasma processing chambers, arranged in the apparatus main body so as to be able to reciprocate in the horizontal and vertical directions. ,
A pusher mechanism that pushes up wafers stored in a wafer cassette fixedly placed on a stage of the apparatus main body from below; and a pusher mechanism that clamps the wafers pushed up by the pusher mechanism at appropriate intervals, and that operates in conjunction with the pusher mechanism. a charger mechanism for transferring the wafer to the boat on the main body stage; and a charger mechanism for horizontally clamping the boat on which the wafer has been transferred and lifting it up to the height of one of the horizontal tubular chambers; and a lifter mechanism that lifts up the boat on the rack that is pulled out from the horizontal tubular chamber after plasma processing is completed and places it again in the fixed position on the main body stage. That is.

[Effect]

In the plasma processing apparatus configured as described above, the wafers stored in the wafer cassette fixed at the start position on the stage of the apparatus main body are pushed up by the pusher mechanism, clamped by the chamber mechanism, and moved together with the pusher mechanism to the lift position. The clamped wafer is transferred to a boat fixed at that position in cooperation with the pusher mechanism, and then the charger mechanism moves to a standby position and waits.

The transferred wafers are lifted together with the boat through the operation of the lifter mechanism and placed on the rack of the open lid of the horizontal tubular chamber arranged in upper and lower stages.Then, the lid is closed and the wafers are placed inside the chamber. The wafer is plasma treated.

When the processing is completed, the lid is opened and the boat is pulled out, and the processed wafers are automatically carried out from the chamber in the same manner as described above, and the wafers are then subjected to plasma processing alternately in the two chambers in the same manner.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Fig. 1 is a partially cutaway front view showing an outline of an example of the device of the present invention, Fig. 2 is a side view, and Fig. 3 is a plan view. (hereinafter referred to as wafer) 2 horizontal tubular chambers (hereinafter referred to as chambers) consisting of two independently configured horizontal tubular chambers (upper and lower).
3, a pusher mechanism 7 for pushing up the wafer 2 stored in a wafer cassette (hereinafter referred to as cassette) 5 placed on the main stage 4 from below through the stage opening 6; a charger mechanism 8 that clamps the pushed-up wafer 2 and transfers it to a wafer boat (hereinafter referred to as boat) 9 on the stage 4;
The moving mechanism 10 of the charger mechanism and the boat 9 are carried into the chamber 3, and the
It is equipped with a lifter mechanism 11 that carries out transport from the inside, and these are configured to be interconnected.

The chamber 3 is made of quartz and is arranged in two stages, upper and lower.

Each chamber 3 is equipped with an automatically controlled front opening/closing lid, and a rack 12 is provided inside the chamber 3 for placing the boat 9 in a non-contact state with the inner circumferential wall of the chamber. It is inserted into the chamber 3 and subjected to plasma treatment,
Further, the processed wafer is pulled out from the chamber 3 by the opening operation of the opening/closing lid.

As shown in FIG. 1, the clamp mechanism 8 is located above the pusher mechanism 7, and
Both mechanisms are interconnected and can reciprocate in the direction of the solid arrow indicated by the number 400.

The pusher mechanism 7 is shown in Fig. 1 and Fig. 4 A, B.
As shown in FIG. 1, the pushers 13, 13' include two pairs of left and right pushers 13, 13' and an elevating mechanism thereof, and the pushers 13, 13' have a large number of wafer retaining slits 14, 14' in the radial direction of their upper surfaces. 2 left and right 1
It is horizontally attached to the upper end of the set of poles 15, 15'.

The lower ends of the poles 15, 15' are attached to a base 16, and a screw bearing 1 is mounted at the center of the base 16.
7 is provided, and one threaded rod 18 is erected through the bearing 17. screw rod 18
An encoder 19 is provided at the upper end, and a motor 20 for rotating the threaded rod 18 is attached to the lower end. Therefore, the pushers 13, 13' are integrated with the base 16 through the poles 15, 15', and are designated by the number 401 in FIG.
It is designed to rise (or fall) in the direction of the solid arrow shown by.

The charger mechanism 8, which is connected to the pusher mechanism 7 and clamps the wafers 2 pushed up by the pusher mechanism 7 at appropriate intervals, includes wafer hangers 21, 21', and wafer hangers 21, 21', as illustrated in FIGS.
It includes wafer stoppers 22, 22 and driving means for the wafer stops 22, 22'.

The wafer hangers 21, 21' are a pair of left and right, and in the slightly lower longitudinal direction of each are horizontally elongated holes 23, 23' with a required width for the wafer stoppers 22, 22' to enter and retract. At the same time, a large number of slits 24, 24' for locking the wafer 2 (or the processed wafer 2') are provided at equal intervals in the vertical direction of each opposing inner surface.
The wafer hangers 21, 21' are disposed below the pushers 13, 13', and are screwed to the base plate 25.

On the outside of the wafer hangers 21, 21', arm parts 27, 27' are provided at both ends for screwing and fixing to horizontal rods, which will be described later.
A pair of left and right arms 26, 26' integrally having flat plate parts 28, 28' are disposed between the lower parts of the wafer stoppers 27', and a band-like wafer stopper 22, 22' connects the tip end with the wafer guide surface to the wafer hanger 21,
They are fixed in a perpendicular manner so as to face inward from the horizontally elongated holes 23, 23' of 21'.

As shown in FIG. 8, slits 29 and 29' are provided at the tips of the opposing wafer stoppers 22 and 22' at intervals of one pitch between the wafers 2 and 2' in the longitudinal direction. There is.

That is, the slits 29 of the left wafer stopper 22 and the slits 29' of the right wafer stopper 22' are offset from each other by one pitch of the wafers 2, 2', and each slit 2
9, 29' correspond to the slits 24, 24' of the wafer hangers 21, 21', and 1 of the wafers 2, 2'.
The wafers pushed up by the pushers 13 and 13' are arranged at intervals of one wafer between the left wafer hanger 21 and the right wafer stopper 22' (or the right wafer hanger 21'). It can be clamped with the wafer stopper 22) on the left side.

As shown in FIGS. 5 and 6, the pair of arms 26, 26' has arm portions 27, 27,
27', 27' are fixedly suspended by being screwed to a pair of horizontal rods 30, 30' which are pivotally supported by the plate 25. The ends of the transverse rods 30, 30' extend outward from the plate 25 via bearings 31, 31', and the brackets 3 are attached to the plate 25.
It is rotatably supported by fixed bearings 33, 33' via 2, 32'.

A pair of left and right cranks 34, 34' are fixed to the rod portions of the horizontal rods 30, 30' between the plate 25 and the bearings 33, 33' facing each other, and the free ends of the cranks 34, 34' are connected to the plates. The left and right horizontal rods 30, 30' are connected to the cylinders 35, 35' attached to the cylinders 25, 35', respectively, and the left and right horizontal rods 30, 30' are connected to the cylinders 35, 35' attached to the cylinders 35, 35', respectively. At the same time, the wafer stopper 22, 22' swings in the direction of the solid line arrow shown by the numeral 403 in FIG. The wafers 2 and 2 move in the direction of the solid arrow shown by the number 404 in FIG.
2' is clamped and released.

Incidentally, the driving of the cylinders 35, 35' is automatically controlled by a sensing means including a sensor (not shown).

As mentioned above, the charger mechanism 8 and the pusher mechanism 7 are connected vertically, and are indicated by the number 400 in FIG.
The moving mechanism 10 is reciprocated in the direction shown by the solid line arrow, and a belt drive system is used as an example of the moving mechanism 10.

That is, as shown in FIGS. 4A and 9, the plate 36 in the pusher mechanism 7,
A plate 39 fixed to a plate 38 connected to the base plate 25 of the charger mechanism 8 on the outside of the main body plate 37 is inserted through two upper and lower horizontally elongated holes 40 opened in the main body plate 37 and attached to four pillars 41 fixed thereto. Therefore, they are interconnected.

As shown in FIG. 9, four guide blocks 42 are fixed to the upper, lower, left and right sides of the inner surface of the plate 39, and the U-shaped grooves 43 of these blocks 42 are connected to two upper and lower guide rails fixed to the main body plate 37. 44, and is slidably engaged with the plate 3.
When the pusher mechanism 7 and the charger mechanism 8, which are connected to each other via the plate 39, reciprocate in the left and right direction through the sliding movement of the block 42, the pusher mechanism 7 and the charger mechanism 8 reciprocate together.

As shown in FIG. 1, FIG. 4A, and FIG. 9,
An endless belt 45 for moving the plate 39 and the like is integrally attached to an intermediate portion of the lower end of the plate 39 by two mounting plates 46 and 47. As shown in FIG. 10, the belt 45 has teeth 48 on its inner surface in the longitudinal direction, and the belt 45 is suspended between a pair of pulleys 49 having teeth 50 that mesh with the teeth 48. The pulley 49 rotates forward (or reverse) in response to the forward (or reverse) rotational force of the motor 51 connected to the pulley 49, which causes the plate 39 to move together with the belt 45, thereby driving the motor 51. is the other pulley 4
9 is automatically controlled by sensing means including an encoder 52 (see FIG. 1) and a sensor (not shown), which are directly connected to the encoder 52 (see FIG. 1).

The wafers 2 clamped at predetermined intervals by the charger mechanism 8 are placed in an opening 75 on the stage 4.
The wafer is transferred to a wafer boat 9 fixedly placed on the stage 4, and this boat 9 is automatically carried into the chamber 3 by a lifter mechanism 11.

The lifter mechanism 11 has a known structure, and its outline is shown in FIG.

In the figure, a pair of guide rails 54 are fixed on both sides of the lifter base 53 in the main body 1 and are opposed to each other in the vertical direction.The lower ends of these rails 54 extend below the main stage 4, and the upper ends are slightly above the upper chamber 3 It extends to

Two large and small pulleys 56 and 57 are rotatably provided between the left and right guide rails 54 and 54 located below the main stage 4 via a shaft 55, and a small pulley 57 is also provided between the upper ends of the guide rails 54. A corresponding pulley 58 is rotatably supported via a shaft 59, and these upper and lower pulleys 58
An endless belt 60 is suspended between 8 and 57.

A motor 61 is provided below the guide rail 54 via a mounting plate (not shown), and
A pulley 62 and a large pulley 5 directly connected to this motor 61
An endless belt 63 is suspended between the belts 6 and 6, and the forward (or reverse) rotational force of the motor 61 is transmitted to the belt 60 to move it upward (or downward).

The belts 60, 63 have the same structure as the belt 45, and the pulleys 56, 57, 58, 6
2 has the same structure as the pulley 49.

A hanger mounting plate 64 is fixed to the outer surface of the belt 60, and the inner groove of this mounting plate 64 engages with both guide rails 54, and as the belt 60 moves up and down, it integrally functions with the rails 54 as a guide. 1st
The hanger mounting plate 64 is designed to move up and down in the direction of the solid arrow indicated by the number 406 in the figure.

A pair of left and right arms 6 are attached to the hanger mounting plate 64.
6 (only one arm 66 is shown and the other is omitted in FIG. 1), the left and right arms 66 horizontally support the boat 9, and the boat 9 is horizontally supported by a belt drive. The boat is placed on the rack 12 of the chamber lid by rising, and the boat 9 is horizontally supported from above the rack 12, and the stage 4 is lowered by lowering via a belt drive.
A boat 9 is placed on top.

The operation of this embodiment described above is as follows.

A wafer cassette 5 in which wafers 2 to be subjected to plasma processing are arranged is placed and set across the opening 6 in the main stage 4.

At this time, the pushers 13, 13' are located directly below the stage opening 6. This situation is shown in FIG.

In this state, the motor 20 and encoder 19
When energized, the pushers 13, 1 fixed to the poles 15, 15' are caused by the screw movement of the screw rod 18 and the screw bearing 17 due to the forward rotation of the motor 20.
3' through the opening 6 and its slit 14,1.
The wafer hangers 21, 21' are pushed up and raised to a height where they can be clamped while the wafer 2 is held on the wafer 4'.

Then, the wafer hangers 21, 21' clamp the wafer 2 pushed up by the driving of the cylinders 35, 35'.

Next, the pushers 13, 13' are connected to the motor 20.
The pusher mechanism 7 descends from the stage opening 6 and stops at the initial position in response to the reverse rotation of the motor 51, and the belt 45 is driven by the forward rotation of the motor 51, and the pusher mechanism 7 is connected to the belt 45 via the plate 39.
The charger mechanism 8 that clamps the wafer 2 moves along the guide rail 44 to a position (lift position) where the wafer 2 is transferred to the boat 9 shown in FIG.

A boat 9 is placed at the lift position, straddling the stage opening 6.

When the wafer 2 reaches the lift position in a clamped state, the pushers 13, 13' in the pusher mechanism 7 rise through the opening 6 and lift the clamped wafer 2 through its slit 14,
It is locked and supported by 14'.

When the wafer 2 is supported by the pushers 13, 13' and the clamps are released, the pushers 13, 13' are lowered again and the wafer 2 is stored in the boat 9.

Next, the charge mechanism 8 is connected to the pusher mechanism 7.
move to the standby position and wait.

Next, the boat 9 is lifted up slightly above the chamber 3 by the lifter mechanism 11.

That is, the belt 60 due to the rotation of the motor 61
When the hanger 65 is driven, the hanger 65 integrated with the hanger 65 is lowered to horizontally clamp and support the boat 9 with its left and right arms 66, and then the boat 9 is moved by the reverse drive of the motor 61, belt 60, etc. It rises to slightly above Chamber 3, which supported it.

When the hanger 65 rises and stops, the lid of the upper (or lower) chamber 3 is opened and the rack 12 is pulled out from inside the chamber 3, and the hanger 65 is lowered to position the boat 9 on the rack 12. Then, it rises again to its original position and waits.

Then, the open chamber lid was closed,
When the inside of the chamber 3 reaches a sufficient vacuum state, a processing gas is introduced and the wafer 2 is subjected to plasma processing. When the plasma processing of the wafer is completed, the lid of the chamber 3 is opened and the boat on the rack 12 is pulled out. Then, the hanger 65 descends and rises to support the boat 9 containing the processed wafers 2', and after the open lid of the chamber 3 is closed, it descends again and fixes the boat 9 at the lifter position. Then, it rises to a position where it does not interfere with the charger mechanism 8 and waits. Then,
When the pusher mechanism 7 and the charger mechanism 8 both move from the standby position to the lift position and stop,
The pushers 13, 13' rise, support the processed wafers 2' on the boat 9 with their slits 14, 14', and push them up to a height where the wafer hangers 21, 21' can clamp them.

Next, a pair of left and right wafer hangers 21, 2
When the wafer 1' clamps the pushed up wafer 2', the pushers 13, 13' descend again to their original positions, and the charger mechanism 8 moves to the original standby position and stops while still clamping the wafer 2 together with the pusher mechanism 7. .

When it stops at the standby position, the pusher 13,1
3' rises and descends while supporting the clamped wafer 2' with its slits 14, 14' to store the wafer 2' in the cassette 5. The cassette 5 containing the processed wafers 2' is moved for the next process, and the empty cassette 5 is placed again.
Below, the above series of operations is repeated in the same way, and the upper and lower 2
Fully automatic plasma processing of wafers is performed alternately within the two chambers 3.

〔Effect of the invention〕

However, according to the present invention, since the wafer processing chamber is mounted in two stages, upper and lower, it is possible to almost double the amount of wafers processed per unit space without increasing the area occupied by the clean room. Costs can be reduced.

Further, it becomes easier for one worker to operate a plurality of processing devices, and an increase in the number of personnel can be suppressed, so that the production cost of semiconductor wafers can be reduced from this point of view as well.

Furthermore, by installing two wafer processing chambers in one processing apparatus, the cost of the apparatus can be reduced compared to the case where two apparatuses each having one chamber are manufactured.

Furthermore, since cleanliness is higher in the upper part of a clean room, we designed the chamber to have a two-tiered structure.
The wafer production yield of the upper chamber can be improved.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing an overview of the device of the present invention, Fig. 2 is a side view, Fig. 3 is a plan view, and Fig. 4 is a side view of the pusher mechanism section with A partially shown in cross section. FIG. 4B is a side view of the charger mechanism part shown partially in section, FIG. 5 is a partially sectional side view of an example of the charger mechanism, and FIG. 6 is a partially omitted plan view of the same as above. Figure 7 is 100-10 of Figure 6.
8 is a cross-sectional view taken along line 0, FIG. 8 is a plan view showing the relationship between the wafer guide plate and the stopper, and FIG.
The figure is a partially omitted perspective view showing a mechanism for reciprocating the pusher mechanism and charger mechanism in the left-right direction, and FIG. 10 is a partially omitted perspective view showing the relationship between the belt and the pulley. 1...Device main body, 2, 2'...Wafer, 3...
...Horizontal tubular chamber, 4...Main stage, 5
... Wafer storage cassette, 7 ... Pusher mechanism, 8 ... Charger mechanism, 9 ... Wafer boat, 10 ... Moving mechanism, 11 ... Lifter mechanism, 12 ... Rack, 13, 13' ... Pusher.

Claims (1)

[Claims] 1. Two horizontal tubular chambers 3, which are plasma processing chambers, arranged in upper and lower stages in the apparatus main body 1,
a pusher mechanism 7 which is provided on the apparatus main body 1 so as to be capable of reciprocating in the horizontal and vertical directions and pushes up from below the wafers 2 stored in the wafer cassette 5 fixed on the stage 4 of the apparatus main body 1; A charger mechanism 8 that clamps the wafers 2 pushed up by the mechanism 7 at appropriate intervals and transfers them to the boat 9 on the main body stage 4 in conjunction with the pusher mechanism 7; and a boat on which the wafers 2 are transferred. 9 horizontally and pulled up to the height of any of the horizontal tubular chambers 3, and placed on the rack 12 provided on the opening/closing lid of the horizontal tubular chamber 3, and after the plasma treatment is completed, the horizontal tubular A plasma processing apparatus for semiconductor wafers, comprising a lifter mechanism 11 that lifts the boat 9 on the rack 12 pulled out from inside the chamber 3 and places it again in a fixed position on the main stage 4.