JP4147603B2 - Method to transfer thin plate shape to processing holder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to surface processing of a thin plate-shaped object such as a semiconductor wafer, a liquid crystal substrate, and an optical component, in particular, a wafer surface pattern flattening processing apparatus used in the process of manufacturing a semiconductor integrated circuit. The present invention relates to a method of transferring to a processing holder.
[0002]
[Prior art]
The manufacture of this type of semiconductor integrated circuit according to the present invention incorporates a process of flattening the surface layer irregularities of the wafer circuit pattern by mechanical means in the manufacturing process because of the demand for high integration and miniaturization. At this time, in order to obtain high quality uniformity, along with factors such as the shape accuracy of the processing tool side disk, the processing holder side that holds the wafer also requires various ingenuity, so that the outer periphery of the held wafer is surrounded. It is necessary to reduce the difference between the inner diameter of the arranged control ring and the wafer diameter (insertion clearance at the time of transfer) as much as possible to suppress the wafer fraud behavior during processing.
[0003]
Normally, the wafer transfer (transfer) used in this type of processing equipment is omitted, but the wafer is mounted toward the processing holder that has moved from the processing position and stopped on the transfer position. A method of directly transferring with the arm of the transfer robot or a method of transferring the wafer once on the mounting table are used. In any of the methods, since the mutual center shift between the stop position accuracy on the processing holder side and the wafer side position accuracy is transferred as it is, mechanical position accuracy is required for the related components in the apparatus.
[0004]
In view of the above, Japanese Patent Laid-Open No. 9-115989 discloses a transfer method aiming to allow a certain degree of mutual center shift between the processing holder and the mounting table. In this prior art, (a.) As a pre-supporting means for a wafer, the wafer is floated with a liquid, and the lateral flow phenomenon of the wafer in the horizontal direction is prevented by a mechanical shape restraining means using an outflow prevention ring; .) Main alignment is mainly a phenomenological centripetal action between the surface tension layer formed on the upper surface of the wafer by a method different from the above levitation means and the processing holder side control ring, The point of success or failure is to form a stable surface tension layer.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide another technique aiming to allow a certain amount of mutual center shift between the processing holder and the mounting table.
[0006]
[Means for Solving the Problems]
In the present invention, (a) as a prior support means for a wafer, the wafer is floated with a liquid, and a horizontal wafer cross-flow phenomenon is performed by using a surface tension layer formed between the upper surface of the mounting table and the lower surface of the wafer. It is characterized by blocking by phenomenon means and (b.) Main centering is a mechanism-shaped centering action based on the outer shape of the control ring disposed on the lower surface of the processing holder.
[0007]
According to the present invention, following the first centering action by the surface tension (rough alignment between the mounting table and the wafer), the second centering action by the shape mechanism means (the cores of the mounting table and the processing holder). Alignment) and the third centripetal action (core alignment of the mounting table side wafer and the processing holder side control ring) and wafer holding (water sticking action) on the processing holder side are the processing of the processing holder. As a result, the wafer is transferred in a mechanical operation sequence.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0009]
FIG. 1 is an explanatory view showing the first centering action (rough alignment of the mounting table and the wafer), and FIG. 2 shows the second centering action (centering of the mounting table and the processing holder). FIG. 3 is an explanatory view showing a third centripetal action (centering of the mounting table side wafer and the processing holder side control ring), and FIG. 4 is a view showing wafer holding on the processing holder side. It is explanatory drawing which shows the (water sticking effect | action by pressing) state.
[0010]
Although the entire illustration is omitted, in the present embodiment, after the wafer 1 to be processed is placed on the mounting table 2 using a transfer robot or the like and then transferred to the processing holder 3, the processing holder 3 is An explanation will be given below as one component (wafer transfer) element of the wafer surface pattern flattening processing apparatus in which the processing can be started by moving horizontally to the processing position after rising.
[0011]
Therefore, the height position of the processing holder 3 immediately before the start of the action in this embodiment is higher than the state shown in FIG. 1, that is, more than the necessary space in which the transfer robot or the like can transfer the wafer 1 to the mounting table 2. Waiting at the height position.
[0012]
1 to 4, a small amount of pure water is always supplied to the upper surface of the mounting table 2 (a single supply port is shown in the drawing, but a plurality of supply ports may be arranged). Then, a taper ring 5 and a plurality of fingers 6 are disposed outside the mounting table 2. Furthermore, a control ring 7 having an inner diameter slightly larger than the diameter of the wafer 1 and a holding material (layer) 8 are arranged in the control ring 7 on the lower surface of the processing holder 3.
[0013]
First, the standby state in this embodiment (when the processing holder 3 is raised from the state shown in FIG. 1) will be described.
[0014]
The mounting table 2 has an action of a spring 12 that pushes up the tapered ring support 11 upward from the tow member 10 raised from the base 9 and a spring 13 that pushes up the mounting table 2 upward from the taper ring support 11. And, it is in a state where it has risen most due to the action of the stopper 14 and the end 15 which regulate the respective rise limits. Similarly, the taper ring 5 is also highest.
[0015]
Further, the fingers 6 respectively engaged with the plurality of finger arms 16 are arranged to be opened and closed radially by joints 18 with the finger support 17, and the standby state is arranged on the finger arms 16. Since the convex side of the provided plate cam 19 is in contact with the follower 21 supported by the follower arm 20, it is in an open state. The finger 6 is always subjected to an action in the closing direction by the action of the spring 22.
[0016]
Further, the push-down pin 23 that is operated at the time of the pressing contact (water sticking) in the final stage of the transfer order operation is supported on the mounting table 2 so as to be movable in the vertical direction, and the hinge 24 is pulled by the spring 25. Therefore, it is in a state where it rises most during standby.
[0017]
Next, the first centering action (schematic alignment between the wafer 1 and the mounting table 2, that is, the above-mentioned “pre-wafer support means”) according to the present embodiment will be described.
[0018]
First, a small amount of pure water 4 is always allowed to flow out from the upper surface of the mounting table 2 having a shape approximate to the wafer outer shape to form the surface tension layer 4a. Since the buffer material (layer) 26 that is involved in the pressing contact is disposed on the upper surface of the mounting table 2, the surface tension layer 4 a is correctly formed on the upper surface of the buffer material (layer) 26.
[0019]
In this state, when the wafer 1 is placed on the surface tension layer 4a formed in substantially the same shape as the wafer 1, due to the physical action of the surface tension, the wafer 1 tries to be the same in the horizontal plane (the action of blocking the transverse flow). ). The first centripetal action is performed without a direct relationship with the lifting operation of the processing holder 3.
[0020]
Subsequently, the second centering action, the third centering action, and the pressing contact (water sticking action) automatically performed in a mechanical operation order along the descending operation (stroke) of the processing holder 3. This will be explained step by step.
[0021]
The lowering holder 3 starts to descend from the ascending end and is in a second state between the state where it comes into contact with the pressing pin 23 shown in FIG. 1 and the state where the tapered portion 3a and the taper ring 5 shown in FIG. The centering action (alignment of the mounting table 2 and the lowering holder 3) is performed.
[0022]
Here, in order to establish the mechanical operation order which is the main point of the present invention, first, the mounting table 2 descends preferentially in accordance with the timing of the processing holder 3, then the taper ring 5, and finally It is necessary to use a mechanical means such that the push-down pin 23 is relatively lowered. As this means, there is a link mechanism combination method that is not shown and described in detail, but in this embodiment, a description will be given using a method of making a difference between the spring stiffnesses. That is, the mechanical operation order is determined by setting the spring stiffness to spring 13 << spring 12 << spring 25.
[0023]
Accordingly, between FIG. 1 and FIG. 2, the selective lowering of the mounting table 2 starts when the processing holder 3 descends and comes into contact with the push-down pin 23, and the second centering action is performed. Will be done. At this point, the push-down pin 23 moves as if it is integral with the mounting base 2 from the above-described spring rigidity condition. Therefore, by appropriately setting the height of the push-down pin 23, The wafer 1 that is being kept in contact with the processing holder 3 side continues the first centripetal action described above.
[0024]
In the present embodiment, the single towable member 10 is shown in a simplified manner in the center, but it is obvious that, for example, a parallel link structure with a plurality of towable members follows. When the processing holder 3 is further lowered, during the state shown in FIG. 2 to the state shown in FIG. 3, a third centripetal action (the mounting table 2 side wafer 1 and the control ring 7 on the processing holder 3 side are connected). Centering) is performed. That is, the taper ring 5 starts to descend between FIGS. When the taper ring 5 is lowered, the plate cam 19 and the like are also lowered together via the finger support 17 engaged therewith, but the follower 21 which is in contact with the plate cam 19 and opens the finger 6 is also joined together. As a result, the finger 6 starts to move in the closing direction along the shape of the plate cam 19, and stops in a state where the upper inner wall 6 a of the finger 6 is in contact with the outer shape of the control ring 7.
[0025]
At this time, the diameter of the inscribed circle created by the inner inner walls 6b of the plurality of fingers 6 at a height that can constrain the outer shape of the wafer 1 is expressed as follows: wafer diameter ≦ inscribed circle diameter ≦ control ring inner diameter By doing so, the wafer 1 can be smoothly aligned into the control ring 7. At this time, if the inner and outer diameters of the control ring 7 are not concentric (manufacturing error), for example, the value corresponding to the error can be corrected by the manufacturing dimension “6a-6b” of the plurality of fingers 6. It is self-explanatory.
[0026]
At this point in time, the wafer 1 that has floated from before does not contact the processing holder 3 side and continues the first centering action described above. The core action becomes dominant.
[0027]
Subsequently, when the lowering holder 3 is further lowered, the wafer 1 is transferred to the processing holder 3 side during the state shown in FIGS. 3 to 4, and subsequently, the wafer is held by pressing contact (water sticking action). . When the state shown in FIG. 3 is reached, the lowering of the mounting table 2 reaches the end point when the end 15 and the upper end 10a of the tow member 10 come into contact with each other, and when the processing holder 3 is further lowered, the push-down pin 23 is moved to the spring 25. On the other hand, the wafer 1 is retracted (lowered), and as a result, the wafer 1 begins to approach the holding material (layer) 8 and is brought into a pressing contact (water sticking action) state at the final stage and held on the processing holder 3 side. Will come to be. Although not described in detail, supplementarily, the holding material (layer) 8 is wet with pure water when the processing holder 3 is cleaned in a prior process.
[0028]
Moreover, it is also possible to perform negative pressure suction holding as an auxiliary or substitute for water sticking holding.
[0029]
【The invention's effect】
As described above, in the present invention, even if there is a slight error in the mutual center misalignment (stop position accuracy, etc.) between the mounting table and the processing holder, or the control ring misalignment (part accuracy) with respect to the outer shape of the processing holder. By correcting this, the wafer can be reliably transferred to the processing holder.
[Brief description of the drawings]
FIG. 1 is a view showing a state in which a centering action is started in a wafer flattening apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a state in which the centripetal action is established in FIG.
FIG. 3 is a diagram showing a state in which the centripetal action is established in FIG. 1;
4 is a diagram showing a final state (established with a water sticking action) in the operation sequence of FIG. 1; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Wafer, 2 ... Mounting stand, 3 ... Processing holder, 3a ... Tapered part, 4 ... Pure water, 4a ... Surface tension layer, 5 ... Tapered ring, 6 ... Finger, 6a ... Upper inner wall, 6b ... Middle inner wall , 7 ... Control ring, 8 ... Holding material (layer), 9 ... Base, 10 ... Tow member, 10a ... Upper end, 11 ... Tapered ring support, 12, 13, 22, 25 ... Spring, 14 ... Stopper, 15 ... End, 16 ... Finger arm, 17 ... Finger support, 18 ... Joint, 19 ... Plate cam, 20 ... Follower arm, 21 ... Follower, 23 ... Pushing pin, 24 ... Hinge, 26 ... Cushioning material (layer).

Claims (1)

A thin plate of sorting target, to float the thin plate-like object by flow out pure water from nono an upper surface of a table having a multiplication Nomen of the thin plate-shaped object and the same shape dimensions, the said sheet-like object a plurality of fingers to form a surface tension layer in the shape, perform centering that by the surface tension of the tension layer, and, although wrap thin plate material that works toward the center as the outside of the nono stand However, the outer surface of the control ring disposed so as to surround the outer periphery of the thin plate-shaped object, the movement of the finger is stopped, the thin plate-shaped object is restrained by the inner inner wall of the finger, and the thin plate dimensional object is centering into said control ring, said control Haise' is being pressed in close contact with the holding member methods Ru re transferred to the working holder a thin plate prepared by said Rukoto in the ring.

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