JP2003077880A - Cleaning and transfer method of wafer, and jig for wafer cleaning and transfer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the possibility of contamination and dust generation by making it possible that a worker does not touch a carrier, which can be carried from a cleaning bath to a dryer, since a handle is attached on the carrier, the carrier is taken out from the cleaning bath and put on a temporary holding table, the handle is detached, the worker wearing rubber gloves throws the carrier in the dryer, holding the carrier by hands, when wafers accommodated in the carrier are dipped in the cleaning tank repeatedly, cleaned and dried by putting the wafers in a dryer, so that the possibility of the gloves of the workers to touch the carrier exists and the wafer and contamination and dust generation being caused, and possibility also exists that hands of the worker are inserted in the dryer and contamination and dust generation are caused to the dryer. SOLUTION: A carrier holder 18 in which the upper part and the rear part are opened and a lever is installed is dipped in the cleaning bath 17, the carrier 10 in which the wafers 11 are accommodated is stored in the carrier holder 18, and the wafers are cleaned. When cleaning is finished, the carrier holder 18 is slanted forward by pushing the lever, the rear of the carrier 10 is clamped with a carrier clamp, and the carrier is carried in the dryer as clamped.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a Si wafer, Ga
The present invention relates to a method for transporting a wafer such as an As wafer and an InP wafer to a dryer without contaminating the wafer, and a jig therefor.

[0002]

2. Description of the Related Art When cleaning wafers such as Si wafers, GaAs wafers and InP wafers, a large number of wafers are laid in parallel in a cleaning container and cleaned. A cleaning container that holds a large number of wafers is sometimes called a wafer carrier or a wafer cassette. Here, it is called a carrier.
A wafer carrier is a holding container for wafers that is open at the top and bottom to allow water to pass through the top and bottom, and is of various types. Different carriers are used depending on the size of the wafer.

The carrier has front, rear, left and right walls, and the left and right inner walls have grooves for vertically passing the wafer. The bottom of the left and right inner walls of the carrier is narrow so that the wafer does not fall. Even if the bottom portion is narrowed, there may be a case where the curved curved constriction along the arc of the wafer is formed, and there is also a case where the bottom portion is formed into a linear shape that only contacts two points on the edge of the wafer. The number of wafers that can be accommodated in one carrier varies from 25 to 50. There are several types of wafer holding pitches.

The basic carrier is, for example, Japanese Patent No. 976.
No. 767 (Japanese Patent Application No. 50-109905). The carrier has various shapes and various proposals have been made. JP-A-4-306833, JP-A5-2
1588, JP-A-8-78371, JP-A-64
Many unique carriers have been invented, such as -22031 and Jitsukaihei 2-132942.

A container for holding a large number of wafers upright is called a carrier when the left and right walls are parallel to each other, and a boat when the left and right walls are outwardly inclined so as to open widely upward. Sometimes it makes a distinction. The material is polypropylene or PFA (Per FluoroAlcoxy Fluororesins). Both are divided into a main body and a handle. The protrusion, hole, etc. of the handle is hooked on the hole, groove, protrusion, etc. of the carrier. If you want to fully immerse the carrier in the cleaning tank for cleaning, remove the handle. When the carrier is lifted from the cleaning liquid, an operator manually hooks the handle on the carrier to lift the handle.

The wafer is cleaned at various stages. There are various cleaning liquids. Cleaning is an important step in semiconductor manufacturing. After washing, it is put into a dryer and dried by hot air.

[0007]

The present invention is concerned with the process of withdrawing the carrier from the wash liquor and into the dryer. An operator wearing rubber gloves attaches a handle to the carrier, pulls up the carrier, opens the door of the dryer, and inserts it into the door. Even with rubber gloves, human hands generate dust (dust). Also, holding the carrier with gloved hands can sometimes contaminate the wafer.

FIG. 1 is a perspective view showing an example of a conventional wafer cleaning / drying apparatus. On the cleaning tank base 1, the first cleaning tank 2, the second cleaning tank 3, the third cleaning tank 4, the fourth cleaning tank 5, the fifth cleaning tank 5,
The cleaning tanks 6 are arranged in order. The first cleaning tank 2 and the third cleaning tank 4 are called SC tanks (spar clean tanks) and contain a weak alkaline cleaning liquid. The second, fourth and fifth cleaning tanks are pure water cleaning tanks. 25 or 5 stored in carrier
Zero wafers are sequentially dipped into the cleaning tanks 2 to 6 and finally housed in the dryer 7 together with the carrier. The worker temporarily places the carrier on the dryer top plate 8, opens the dryer door 9, lifts the carrier, and feeds it into the dryer 7 from the inlet. Such cleaning steps are now commonplace. It has the drawback of possible wafer contamination and long transport times.

The problem is the transfer from the last washing tank 6 to the dryer 7. The process of pulling up the carrier from the cleaning tank and loading it into the dryer will be described in detail with reference to FIG. The star-shaped mark represents the inconvenience caused in the process.

FIG. 2 (1) shows a state before the cleaning in which the carrier 10 is immersed in the cleaning tank 12. Alternatively, it may be said that the carrier 10 is pulled up from the cleaning tank 12 after cleaning. A large number of wafers 11 are vertically accommodated in the carrier 10. An operator brings the carrier 10 into the washing tank 12 with the handle 14 of the carrier 10 with the right hand with gloves. Then, the handle 14 is removed and washed. After cleaning, the worker wearing the rubber gloves 15 handles 1
4 is attached to the carrier 10 and the carrier is pulled out of the cleaning liquid 13.

FIG. 2 (2) shows a state in which the carrier 10 pulled up from the cleaning liquid 13 is temporarily placed on the holding table 16. The temporary holding table 16 does not exist in particular, and it may be on the cleaning tank table 1 in FIG. 1 or on the dryer top plate 8. Since it is placed on the temporary holding table 16, there is a possibility S of contamination of the wafer or carrier at that time.

As shown in FIG. 2C, the temporary holding table 16
The handle 14 is removed from the carrier 10 placed on. This is because the drier 7 cannot be entered without the handle 14. At this time, there is a drawback that it takes extra time (W) to remove the handle 14 from the carrier 10.

In FIG. 2 (4), the hand wearing the rubber gloves 15 is
The state where the left end of the carrier 10 placed on the temporary holding table 16 is grasped is shown. There is a possibility of dust generation (T) because the rubber gloves come into contact with the carrier and the wafer.

FIG. 2 (5) shows a state in which the hand of the worker wearing the rubber gloves 15 is carrying the carrier 10.
At that time as well, since the rubber gloves 15 and the carrier are in contact with each other, dust is generated.
There is a possibility of

FIG. 2 (6) shows a state in which the carrier 10 has inserted the carrier 10 into the dryer 7 by the hand of an operator wearing rubber gloves. Since human hands can get inside the dryer 7, there is a possibility (V) of dust generation. Since the operator carries the carrier directly by hand, there is a risk that the carrier, the wafer, and the dryer will be contaminated and dust will be generated (S, T, U, V). In addition, there is a drawback that it takes time (W) because the handle is attached or removed.

In order to transfer the wafer from the cleaning tank to the dryer, a large number of wafers are set up in parallel in a carrier, a handle is hooked on the carrier, the handle is gripped by hand, and the carrier is lifted. This is the conventional method of pulling the carrier out of the last cleaning liquid and introducing it into the dryer. Workers wearing rubber gloves directly touch the carrier to perform work, which causes problems such as contamination and dust generation. There is also a problem that it takes time to attach and detach the handle. Although it has not been considered as a problem in the past, the present inventor should think that it should also be a problem.

Therefore, the possibility of dust generation and contamination is lower,
It is a first object of the present invention to provide a method of transporting a carrier that can reduce the time for attaching and detaching the handle. It is the second aspect of the present invention to propose a new jig used for that purpose.
Is the purpose of.

[0018]

According to the wafer cleaning / transporting method of the present invention, a carrier holder, which is a container having an upper portion and a rear portion opened and a bottom portion separated by a crosspiece and a lever on the side surface, is immersed in a cleaning tank to store a wafer. Place the carrier on the carrier holder to clean the wafer, and after cleaning, push the lever forward to tilt the carrier holder forward, lift the rear end of the carrier, and grasp the rear end of the carrier with the carrier grip. The carrier is taken out with, and the carrier is gripped by the carrier and put into the dryer.

By doing so, the gloves do not touch the carrier, so that contamination and dust generation can be avoided. It is possible to save the time for attaching and detaching the handle once.

The carrier holder used to lift the rear end of the carrier has a low rear wall, a high front wall, a left wall and a right wall with inclined sides, a lever provided on either of the left and right wall surfaces, and a cleaning liquid. The bottom part has a plurality of crosspieces so that the carrier can be held, and the rear end of the carrier can be lifted by tilting the lever forward.

The carrier grip for carrying the carrier after cleaning includes a wide right wing and a left wing having left and right grip sides for holding the rear end of the carrier, and an open / close handle and a grip handle which are continuous behind the right wing and the left wing. A hinge shaft for allowing the open / close handle and the grip handle to rotate, and a spring for giving an elastic force to the open / close handle and the grip handle in the direction of closing the right and left wings.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is a perspective view showing an example of the arrangement of a cleaning tank and a dryer used in the present invention. Although it is almost the same as FIG. 1 described as a conventional example, it is different in that the carrier is immersed in a special jig in the last cleaning tank. The special jig 18 is provided to facilitate the removal of the carrier from the cleaning tank. Cleaning is carried out with the carrier in the jig 18. Since this jig holds the carrier, it is called a carrier holder 18. The stirring movement of the cleaning liquid is rarely impeded by the presence of the carrier holder 18.

FIG. 4 is an enlarged perspective view showing only the last cleaning tank portion. Since the cleaning tank 6 of FIG. 1 is a little small for inserting a jig, the transport cleaning tank 17 is a slightly larger cleaning tank. Since it is a washing tank for facilitating the transportation of the carrier, it is referred to as a carrying washing tank 17. Wash tank 17
It is fixed and is not transported. Only the carrier is transported. Don't be confused.

For the sake of clarity, FIG. 4 shows the inside of the washing tank with the washing liquid omitted. It does not mean that the tank is transparent. Actually, there is a cleaning liquid, and the wafer and carrier are immersed in the cleaning liquid. Wash tank 17
There is a jig 18 with a lever made of plastic in which the carrier 10 accommodating the wafer 11 is put. Wash in that state. When taking out, the lever is pushed forward to lift the back of the carrier holder 18, and the protrusion at the rear end of the carrier is sandwiched by the transport jig 40 such as a clip, and the carrier holder 18 is sandwiched by the transport jig 40 and carried to the dryer 7. This jig is called a carrier grip 40 because it grips and carries the carrier.

By doing so, it is not necessary to attach a handle when removing the carrier from the cleaning liquid. The rubber glove does not come into direct contact with the carrier because the carrier is used to hold the carrier. There is an advantage that the inside of the dryer is not soiled because gloves do not enter the inside of the dryer. Such a point is shown in FIG.
Let me explain again. Before that, the carrier holder 18 and the carrier grip 40 will be described in detail.

A carrier holder used for facilitating the removal of the carrier from the cleaning liquid in the present invention will be described with reference to FIGS. FIG. 5 is a perspective view of the carrier holder 18 as viewed from the right rear. 6 is a right side view of the same thing, FIG. 7 is a vertical right side view, FIG. 8 is a front view, and FIG. 9 is a vertical front view. The carrier holder 18 is a container that is asymmetrical in the front and rear and has an upper opening and a lower opening.

A tall front wall 20, followed by a triangular right wall 21, a low rear wall 22, followed by a generally triangular left wall 23.
Form a frame structure. It has a triangular shape, but right wall 21 and left wall 2
3 has a right joint piece 24 and a left joint piece 25 which are protruded upward in the middle thereof. A lever 26 extending obliquely rearward is fixed to the outside of the left joint piece 25 via a fixing piece 27.
On the outer side of the right joint piece 24, there is a concave circle portion 28 that projects outward in a cylindrical shape. On the outside of the left joint piece 25, a convex circular portion 29 is formed at a position on the same axis as the left joint piece 25. The fixing piece 27 described above
Is above the convex circle 29.

The container 18 is open at the top. It is for loading and unloading the carrier. The carrier holder 18 is also open downward so that the cleaning liquid can pass through. However, since the carrier 10 cannot be held when it is completely opened downward, some crosspieces are formed so as to extend over the right wall 21 and the left wall 23. The first bar 34, the second bar 35, the third bar 36, the fourth bar 37, and the like are arranged from the side closer to the front wall 20. The wash water must pass through and the carrier 10
Therefore, a thin crosspiece is provided because it is necessary to grip the.

The wafer carrier is loaded into the carrier holder 18 as shown by the chain double-dashed line in FIGS. The carrier 10 holds the wafer parallel to the front and rear walls 20,22. The front and rear walls of the carrier are carrier holders 1
8 are close to the front and rear walls, respectively. Therefore, the wafer surface becomes parallel to the front wall 20 and the rear wall 22 of the carrier holder 18.

An example of the dimensions of the carrier holder will be described.
The front wall 20 has a height of 90 mm and a thickness of 3 mm, and the rear wall 22 has a height of 15 mm and a thickness of 5 mm. The thickness of the right wall 21 and the left wall 23 is 3 mm. The right wall 21 and the left wall 23 have a height of 90 mm in the front and 15 mm in the back. The distance between the inner surfaces of the right wall 21 and the left wall 23 (width of the front wall and the rear wall) is 170 mm. It is wider than the width of the carrier. The distance between the inner surfaces of the front wall and the rear wall is 150 mm. It is longer than the front-back length of the carrier.

The front and rear widths of the first rail 34 and the fourth rail 37 are 10
mm, the front and rear widths of the second rail 35 and the third rail 36 are 5 mm. The distance from the inner surface of the front wall 20 to the first rail 34 is 10 mm
Is. The distance between the first rail 34 and the second rail 35, the distance between the second rail 35 and the third rail 36, and the distance between the third rail 36 and the fourth rail 37 are 3
2 mm is common. The width of the left joint piece 25 and the right joint piece 24 is 6
It is 0 mm. The length of the lever 26 is 170 mm.
The distance from the bottom of the left and right walls 21, 23 to the top of the left and right joint pieces 24, 25 is 137 mm. The height of the front wall 20, the center of the concave circle 28, and the center of the convex circle 29 are the same height (90 m
m).

The carrier holder 18 remains immersed in the cleaning liquid. Therefore, unlike the carrier, there is no need to attach or detach the handle. Actually, you do not need a handle with both ends,
The lever is integrally fixed to one wall surface. Since the carrier holder 18 does not need to be lifted from the cleaning liquid, it does not require a double-sided handle. The lever 26 is attached diagonally because it needs to be tilted forward. The reason why the lever is attached to the left side is that the carrier is taken out with the right hand.

The upper part is opened because the carrier is inserted from above and the carrier is taken out from above. The crosspiece is provided on the bottom surface so that the back of the carrier 10 is lifted when the lever 26 is pushed inward. In addition, the bottom is a cross so that the cleaning liquid can pass freely. The bottom surface of the carrier is also an opening so that the cleaning liquid can pass vertically.

The front and rear of the carrier holder 18 are asymmetrical so that the carrier can be easily pulled out from the rear side. By raising the carrier 10 by the height of the rear wall 22, the carrier 10 can be drawn to the hand.

Next, the carrier grip 40 for gripping and taking out the rear end of the carrier 10 will be described with reference to FIGS. FIG. 11 is a perspective view seen from below, and FIG.
Is a perspective view of the carrier grip seen from above, and FIG. 13 is a transverse sectional view.

This is a mirror-symmetrical combination of a left piece 41 and a right piece 42 having an L-shaped cross section. Left piece 41 and right piece 42
Is very similar but a little different. This is because it is easy to hold it with the right hand and open and close it to maintain the closed state. Left piece 41,
The right piece 42 is made of transparent plastic. If it is opaque, it is difficult to see from the hand side whether or not the gripping side properly holds the carrier.

The left piece 41 has a left wing 43 which is a flat surface, and an opening / closing handle 44 which is orthogonal to the left wing 43 and is continuous with the left wing 43,
At the outer end portion of the left wing 43, a left grip side 45 bent forward inward is formed. The left wing 43 is a portion that contacts the rear wall of the carrier when the carrier 10 is gripped. Opening and closing pattern 4
4 is thicker because it requires more force. The outer half is removed from the square frame structure.

The right piece 42 is composed of a right wing 46 which is a flat surface, a grip handle 47 which is perpendicular to the right side of the right wing 46, and a right gripping edge 48 which is bent forward inward at the outer end of the right wing 46. . When the carrier grip 40 grips the carrier 10, the right wing 46 and the left wing 43 both receive the carrier 10.
Touch the back wall of. The grip handle 47 has a square frame structure. That is, the through hole 49 is opened laterally. When holding the carrier grip 40, insert the index finger, middle finger, ring finger, and little finger into the through holes 49. Since gripping force is applied, the grip 47 is thicker than the right wing 46.

Vertical grooves 38, 39 are cut in the facing surfaces of the grip handle 47 and the opening / closing handle 44, and a cylindrical hinge shaft 50 is inserted therein. A thin folded piece 51 is adhered to a portion which becomes a boundary line between the left piece 41 and the right piece 42 when closed. When opened, the folded piece 51 is also opened. The folded piece 51 is a member that connects the left piece 41 and the right piece 42. This can be omitted.

A U-shaped upper spring 52 and a lower spring 53 are provided to close the grip handle 47 and the open / close handle 44. The upper spring 52 and the lower spring 53 have a strong elastic force and close the left wing 43 and the right wing 46. Although FIG. 11 is shown upside down, the carrier grip 40 is held with the right hand by reversing this. The palm of the right hand hits the outside of the grip handle 47. The thumb corresponds to the push side 56 on the outer side of the opening / closing handle 44. The remaining four fingers pass through the through holes 49.
The grip handle 47 is firmly grasped by the middle finger, the ring finger, and the little finger. The index finger comes to push the push side 56 of the open / close handle 44. Of course, workers wear rubber gloves.

When the pushing side 56 is strongly pulled by the thumb and forefinger, the opening / closing handle 44 contacts the surface of the grip handle 47. Hinge shaft 50
The left piece 41 and the right piece 42 open centering on. The distance between the right wing 46 and the left wing 43 becomes wider. Left and right grip pieces 45 in that state,
The protrusion of the rear end of the carrier is grasped by 48. The carrier 10 can then be lifted by the carrier grip 40. The rubber gloves do not contact the carrier 10. Therefore, there is no problem of dust generation and contamination due to contact with rubber gloves.

A method of transporting the cleaning tank of the present invention to the dryer will be described with reference to FIG. FIG. 10 (1) shows a state in which the operator inserts the carrier 10 containing the wafer 11 with the handle 14 into the carrier holder 18 which is previously submerged in the last cleaning tank. The difference from (1) of FIG. 2 is that there is a carrier holder 18 and the carrier is put therein. In (2) of FIG. 10, the worker has removed the handle 14 from the carrier 10. The wafer is washed in that state. When the cleaning is completed, the operator tilts the lever 26 of the carrier holder 18 to the other side with his left hand to lift the back of the carrier holder 18 as shown in FIG. By doing so, the rear end of the carrier 10 can be lifted from the cleaning liquid into the air. Note that the carrier is being lifted without the handle attached.

FIG. 10 (4) shows a state in which an operator wearing a rubber glove holds the back of the carrier 10 lifted from the cleaning liquid by the carrier grip 40. It should be noted that the carrier is gripped by the carrier grip 40 without the handle. Since the rear wall of the carrier holder 18 is low, the carrier may be lifted a little and the carrier may be pulled out. As shown in FIGS. 10 (5) and 6 (6),
After pulling it out, the operator carries it into the dryer 7 while holding it with the carrier grip 40. There is no need to remove the handle, so there is no need to put the carrier on the temporary holding table. Since the worker's gloves do not touch the carrier, the carrier or wafer is not contaminated by the gloves. Moreover, since the gloves of the worker do not enter the inside of the dryer, the inside of the dryer does not generate dust and is not contaminated. There are various such advantages.

[0044]

EFFECTS OF THE INVENTION A carrier holder having an open upper portion and a rear portion is retained inside a cleaning tank, and a carrier containing a wafer is placed thereon for cleaning. When the carrier is removed after cleaning, the carrier holder is tilted forward so that the carrier is above the cleaning liquid, and then the carrier is gripped and the carrier projection is gripped. It is easy to take out because there is no need to attach a handle. There is no need to remove the handle because it is not attached. In order to remove the handle, conventionally, the carrier was placed on the temporary holding table and then the handle was taken, but such a troublesome operation becomes unnecessary. Since it is not placed on the temporary holding table, the problem of contamination from the temporary holding table is eliminated. Furthermore, since the carrier is held by the carrier and is not directly touched by the hand, contamination and dust generation by the hand does not pose a problem.

The time required for actual transportation was compared.
In the case of the conventional method shown in FIG. 2, it took about 10 seconds from the cleaning tank to the dryer. In the present invention, it took about 5 seconds from the washing tank to the dryer. This means that the time of 5 seconds can be shortened for each carrier.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an arrangement of a cleaning tank and a dryer according to a conventional example.

FIG. 2 is a diagram illustrating a conventional method of transporting a wafer carrier from a cleaning tank to a dryer.

FIG. 3 is a perspective view showing an example of an arrangement of a cleaning tank and a dryer for carrying out the present invention.

FIG. 4 is a perspective view showing the inside of a final cleaning tank for carrying out the present invention in a see-through manner.

FIG. 5 is a perspective view of a carrier holder used to tilt the carrier in the present invention.

FIG. 6 is a right side view of the carrier holder.

FIG. 7 is a right side view in vertical section of the carrier holder.

FIG. 8 is a front view of a carrier holder.

FIG. 9 is a vertical sectional front view of the carrier holder.

FIG. 10 is a view for explaining the method of the present invention for transporting a carrier from a cleaning tank to a dryer.

FIG. 11 is a bottom perspective view of the carrier grip.

FIG. 12 is a top perspective view of the carrier grip.

FIG. 13 is a cross-sectional plan view of a carrier grip.

[Explanation of symbols]

1 washing tank stand 2 First cleaning tank (SC1 tank) 3 second cleaning tank 4 3rd cleaning tank (SC2 tank) 5 4th washing tank (1 washing tank) 6 5th washing tank (2 washing tanks) 7 dryer 8 dryer top plate 9 dryer door 10 carriers 11 wafers 12 washing tank 13 Cleaning solution 14 handle 15 rubber gloves 16 Temporary holding table 17 Transport water washing tank 18 carrier holder 20 front wall 21 right wall 22 Rear wall 23 Left wall 24 Right piece 25 Left piece 26 lever 27 fixed piece 28 concave circle 29 convex circle 30 inclined side 31 Inclined side 32 horizontal side 33 Horizontal side 34 First cross 35 second cross 36 Third cross 37 Fourth cross 38 vertical groove 39 vertical groove 40 carrier grab 41 Left piece 42 right piece 43 Left 44 open / close pattern 45 Left grip 46 right wing 47 grip handle 48 right grip 49 through hole 50 hinge shaft 51 folded pieces 52 Upper spring 53 Lower spring 56 push side

Claims (3)

[Claims] 1. A wafer is washed by immersing a carrier holder, which is a container having a lever at its side and a top part and a rear part opened and a bottom part separated by a crosspiece, and placing a carrier containing a wafer on the carrier holder. Then, after cleaning, push the lever forward to tilt the carrier holder forward, lift the rear end of the carrier, grasp the rear end of the carrier with the carrier grip, take out the carrier, and hold it with the carrier grip inside the dryer. A method of cleaning and transferring a wafer, characterized by: 2. A container for mounting a carrier containing a wafer inside a cleaning tank, wherein a low rear wall, a high front wall, a left wall having inclined sides, a right wall, and either of left and right sides. Wafer cleaning characterized by a lever provided on the wall and a plurality of crosspieces at the bottom so that the carrier can be held through the cleaning liquid and the rear end of the carrier can be lifted by tilting the lever forward. A jig for transportation. 3. A jig for holding and carrying a carrier lifted from a cleaning liquid, which has a wide right wing and a left wing having left and right gripping sides for holding and holding the rear end of the carrier, and behind the right wing and the left wing. It is characterized by comprising a continuous opening and closing handle, a grip handle, a hinge shaft for allowing the opening and closing handle and the grip handle to rotate, and a spring that gives elastic force to the opening and closing handle and the grip handle in the direction of closing the right and left wings. A wafer cleaning and transporting jig.