JPH05243199A - Semiconductor wafer housing mechanism and method - Google Patents

Abstract

PURPOSE:To provide a semiconductor wafer housing mechanism and method, where the mechanism houses a semiconductor wafer, which is subjected to grinding work and housed in a cassette, without leaving stains or clouding as tire trace of water droplets on the ground surface of the semiconductor wafer. CONSTITUTION:A surface grinder is constituted, where bars are provided to a cassette 1 provided with side, an opening edge for enabling a lid to be watertightly fitted to the open side of the cassette 1 is provided to the open side, a transfer mechanism 3 is provided adjacent to an elevator 2 where the cassette 1 is placed, and a water tank 4 is provided surrounding the cassette 1, dipping the cassette 1 into water. Furthermore, liquid is reserved in the tank 4 to 1 the cassette 1 underwater, the semiconductor wafers are accumulated in liquid and stored in the cassette 1 through its open side together with liquid, and as the semiconductor wafers are stared as sacked up underwater without being dried up till the are delivered to a following process, the traces of evaporated water droplets are not left on the wafers, and an end-product can be sharply improved in yield.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic surface grinder that vacuum-sucks a semiconductor wafer onto the upper surface of a chuck mechanism and grinds it onto the ground surface of a semiconductor wafer housed in a cassette after grinding. The present invention relates to a mechanism and a method for storing water droplets such as cloudiness without leaving them.

[0002]

2. Description of the Related Art An automatic surface grinding machine for grinding semiconductor wafers of this type stores a large number of semiconductor wafers individually in a cassette on the delivery side, and the cassette on the delivery side can be moved up and down. Placed on a table, transferred by a delivery-side transfer mechanism disposed in front of the elevator table, inverted by vertical rotation of the delivery-side transfer mechanism, and placed on the surface of the preposition device, Prepositioning device performs accurate positioning and cleaning with a jet of liquid, and the precise trajectory of the horizontally-rotatable delivery side transfer arm equipped with a vacuum suction pad at the tip,
It is accurately guided to the chuck mechanism that is formed on the rotary table of the automatic surface grinder at even intervals, and is vacuum-adsorbed securely, and it moves to the next grinding position by intermittent rotation of the rotary table, and the cup wheel at the lower end. The diamond wheel is fixed and the spindle shaft that rotates by the motor automatically descends to start the first grinding.

Next, the semiconductor wafer is transferred to each grinding position together with the chuck mechanism by intermittent rotation of the rotary table, subjected to a predetermined grinding process by the chuck mechanism, and transferred to the final grinding position. Advancing and retracting the storage-side transfer mechanism equipped with a vacuum suction pad after it is sucked and transferred to a cleaning and drying device by a storage-side transfer arm that has a suction pad at the tip and is rotatable in the horizontal direction, and is stored and washed, and then stored. When the storage-side elevator table on which the side-cassette is placed is moved up and down, the storage-side cassette is sequentially stored in the crosspiece of the storage-side cassette from the opening surface.

The above description is for a single semiconductor wafer grinding process. However, when a semiconductor wafer is transferred from the sending-side cassette to the pre-position device through the sending-side transfer mechanism, the next semiconductor wafer is It has an automatic delivery mechanism that is held by the delivery-side transfer mechanism from the delivery-side cassette and waits for the previous semiconductor wafer to be transferred to the chuck position of the rotary table, and repeats these operations continuously. At each chucking position of the chucking mechanism provided on the rotary table, the work is simultaneously and continuously performed.

These automatic surface grinders grind semiconductor wafers by the above-mentioned steps, and most of the steps are usually performed in the atmosphere, but cleaning and alignment in preposition, Alternatively, liquid is used for grinding liquid during grinding, cleaning after grinding, etc., and the liquid is removed with a drying device such as a centrifuge just before storing, but water droplets etc. may adhere. It often happened.

However, the recently demanded semiconductor wafer has a high-precision flatness and a high-quality mirror finish, and even if it is ground by an automatic surface grinder with a high-precision flatness,
After the attached water droplets were evaporated, the traces of the water droplets were stained or clouded, which was an obstacle to improving the yield of the final product.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the semiconductor wafer storage mechanism of the present invention has been rigorously studied, and as a result, an automatic surface grinder is provided with a water tank portion so as to surround at least the cassette,
It is an object of the present invention to solve the above-mentioned problems by providing a mechanism and a method for storing a liquid in the water tank portion, inserting and removing the cassette in a substantially submerged state, and grinding and then sealing a semiconductor wafer together with the liquid in the cassette. It is a thing.

[0007]

The structure of the present invention is an automatic surface grinder that vacuum-sucks a semiconductor wafer to a chuck mechanism and grinds it with a cup wheel grinding wheel disposed above the chuck mechanism, and has an opening surface. A plurality of crosspieces are provided inside the cassette, an opening edge is provided on the opening surface to close the lid, and a transfer mechanism is provided near the elevator table on which the cassette of the automatic surface grinder is placed. , At least a water tank portion surrounding the cassette is provided.

[0008]

According to the present invention, by using the above-mentioned structure, the liquid is stored in the water tank to make the cassette substantially submerged, and the semiconductor wafers are integrated and stored in or near the liquid surface from the opening surface of the cassette. After that, the semiconductor wafer and the liquid are filled in the cassette.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A storage mechanism for a semiconductor wafer according to the present invention which achieves the above object will be described with reference to the drawings of the following embodiments.

FIG. 1 is a schematic plan view of an embodiment for explaining an automatic surface grinder of the present invention, FIG. 2 is a side view for explaining an essential part of the next embodiment, and FIG. 3 is a perspective view of a cassette. is there.

According to the first aspect of the present invention, there is provided an automatic surface grinder which vacuum-sucks a semiconductor wafer W onto the upper surface of a chuck mechanism and grinds the semiconductor wafer W into a cassette 1 after grinding. The present invention relates to a mechanism and a method for storing a semiconductor wafer W on a ground surface thereof without leaving any traces of water droplets such as stains or cloudiness, and vacuum chucks the semiconductor wafer W onto the upper surface of the chuck mechanism 6, In an automatic surface grinder for grinding with a cup wheel grinding grindstone at the lower end of the spindle shaft arranged above 6, a plurality of bars 1b partitioned into shelves are provided inside the cassette 1 having an opening 1a formed on one side. And an opening edge portion 1d for closing the lid 1c in a watertight state on the opening surface 1a, and an elevator table 2 of an automatic surface grinder for mounting the cassette 1 thereon. Is to near the semiconductor wafer W is disposed a transfer mechanism 3 for storing the opening surface 1a of the cassette 1, it is provided with a water tank portion 4 surrounding at least the cassette 1 in the submerged state.

According to the second aspect of the invention, the semiconductor wafer W is vacuum-sucked to the upper surface of the chuck mechanism 6, and the cup wheel grinding of the lower end of the spindle shaft arranged above the chuck mechanism 6 is performed. In an automatic surface grinder that grinds with a grindstone, a plurality of rack-shaped partitions 1b are provided inside a cassette 1 having an opening 1a formed on one side, and a lid 1c is watertightly attached to the opening 1a. An opening edge portion 1d for closing the lid is provided, and a transfer mechanism 3 for storing the semiconductor wafer W from the opening surface 1a of the cassette 1 is provided in the vicinity of an elevator table 2 on which the cassette 1 is placed, and at least a transfer mechanism 3 is provided. Using an automatic surface grinder provided with a water tank portion 4 surrounding the cassette 1 in a submerged state, the water tank portion 4
Liquid is stored in the cassette 1 so that the cassette 1 is substantially submerged,
The semiconductor wafers W are integrated and stored in the liquid in the vicinity of the liquid surface from the opening surface 1a of the cassette 1, and then the cassette 1 is filled with the semiconductor wafer W together with the liquid.

That is, the cassette 1 used in the present invention is for accumulating and storing a large number of semiconductor wafers W individually, and the cassette 1 has a substantially box-like appearance, and an opening whose substantially entire surface is open to one side surface. A surface 1a is formed, and an opening edge portion 1d is provided on the edge portion of the opening surface 1a so that the lid body 1c can be detachably closed in a watertight state, and a sliding groove is formed on the opening edge portion 1d. The lid 1c is formed by sliding the lid 1c through the sliding groove from above to close the lid, or a step is formed on the opening edge 1d and the lid 1c attached to the step is packed. The lid 1 is closed by a means such as fitting through a sealing material such as the above to provide a fixing tool and fixing, and the inside of the cassette 1 is provided with a plurality of rack-shaped partitions 1b, The crosspiece 1b supports the two or three widths of the circular semiconductor wafer W to a slight extent, and It is intended to be integrated stored for each single item.

The automatic surface grinder is provided with a rotary table 5 which rotates intermittently in the center, and a plurality of sets of chuck mechanisms 6 capable of vacuum suction and self-rotating to the rotary table 5 are equally spaced. A spindle shaft, which is shaped and fixed to the lower end of the chuck mechanism 6 with a cup wheel type diamond grindstone and which rotates by itself, is disposed above the chuck mechanism 6.

On the delivery side for delivering the semiconductor wafer W to the chuck mechanism 6 of the rotary table 5, a delivery-side cassette 1, a vertically movable elevator base 2 on which the cassette 1 is placed, and an opening of the cassette 1. A delivery-side transfer mechanism 3 for transferring the semiconductor wafer W to the pre-position 7 from the section,
From a pre-position 7 for cleaning and aligning the transferred semiconductor wafer W, and a delivery side transfer arm 8 having a vacuum pad at the tip for transferring from the pre-position 7 to the chuck mechanism 6 and capable of rotating in the horizontal direction. It consists of

On the other hand, on the storage side for storing the semiconductor wafer W from the chuck mechanism 6 to the storage side cassette 1, the storage side transfer mechanism 3 shown in FIG. By the water flow, the crosspiece 1 of the cassette 1
In the next embodiment shown in FIG. 2, the storage side transfer arm (shown in FIG. 2) is provided with a vacuum pad for adsorbing the semiconductor wafer W on the upper surface of the chuck mechanism 6 and is rotatable in the horizontal direction. Therefore, it comprises a storage-side transfer mechanism 3 for transferring to the cleaning device and accumulating and storing it in the cassette 1 on the storage side of the cleaning device, and an elevator platform 2 for elevating and lowering the cassette 1.

The present invention is a cassette 1 after the storage side grinding process.
1. At least a water tank portion 4 surrounding the cassette 1 in a submerged state is provided, the cassette 1 is placed on an elevator platform 2 which can be raised and lowered, and a storage side transfer provided in front of the elevator platform 2. The mechanism 3 transfers the semiconductor wafer W after the grinding process from the cleaning device 9 to the upper surface of the crosspiece 1b of the cassette 1, and the water tank portion 4 of the present invention, the storage side transfer mechanism 3 and the elevator table 2 together with the cassette 1. May be surrounded by water, or the elevator pedestal 2 and the cassette 1 may be surrounded by the water tank portion 4, or only the cassette 1 may be surrounded by the water tank portion 4. It may be integrated and stored near the surface, as long as at least the cassette 1 is substantially submerged in water and the semiconductor wafer W can be stored in a watertight state together with the liquid.

The storage-side transfer mechanism 3 for accumulating and storing the semiconductor wafers W individually from the cleaning device 9 into the cassette 1 will be described by way of example. In FIG. 1, the semiconductor wafer W is transferred from the cleaning device 9 to the cassette 1 by the water flow. The semiconductor wafer W is transferred together with the liquid by jetting the liquid from below the chuck mechanism 6, and is accumulated and stored in the vicinity of the liquid surface of the water tank portion 4. 2 is a case where the cassette 1, the elevator table 2, and the storage side transfer mechanism 3 are surrounded by the water tank portion 4, and the storage side transfer mechanism 3 is provided between the cleaning device and the elevator table 2 on which the cassette 1 is placed. A transfer mechanism 3 for the reversing arm, which is arranged on the upper surface of the crosspiece 1b of the cassette 1 and vacuum-adsorbs and inverts the semiconductor wafer W after the grinding process. The base shaft is provided upright, and the base shaft is provided with a reversing mechanism in which the base shaft and the horizontal shaft are connected by a rotatable joint in order to invert the horizontal shaft in the vertical direction, and the base shaft and the horizontal shaft are respectively It is equipped with a telescopic type expansion / contraction mechanism, and the base axis is reversed and can be expanded / contracted to be submerged later, and the horizontal axis is the cassette 1
Is provided with a telescopic type expansion / contraction mechanism for freely moving in and out of the opening surface 1a of the device, and a suction pad for vacuum-sucking the semiconductor wafer W is attached to the tip of the horizontal shaft, and further horizontal to the base shaft. The shaft is hollow and communicates with a vacuum pump in order to suck the semiconductor wafer W by vacuum.

The present invention is provided with a water tank portion 4 surrounding at least the cassette 1 in a submerged state, and the water tank portion 4 is provided.
Liquid is stored in the lower part of the cassette 1 so that it is submerged.
Semiconductor wafers W are accumulated and stored slightly above the liquid surface from the opening surface 1a of the cassette 1 onto the crosspiece 1b, or are accumulated and stored in the liquid. The semiconductor wafer W that has been subjected to the cleaning and is cleaned by the cleaning device is attracted by the suction pad of the storage side transfer mechanism 3 including the reversing arm, and the reversing arm is vertically reversed to shorten the base axis. The operation is carried out by aligning the positions in the directions and by the extension of the expansion / contraction mechanism of the horizontal axis, it is transferred onto the crosspiece 1b of the cassette 1 and placed on the crosspiece 1b by opening the vacuum. Is sequentially repeated to accumulate and store a plurality of semiconductor wafers W in the cassette 1, and after the storage, the elevator table 2 is lowered to completely submerge the cassette 1 in the water tank unit 4. The base axis of the reversing arm may be provided so as to pass through the bottom surface of the water tank portion 4. Alternatively, instead of extending the extension mechanism of the horizontal axis of the reversing arm, the semiconductor wafer W that is tilted after the suction release of the semiconductor wafer W is passed to the semiconductor. The wafer W may be slid by the water flow and its own weight and transferred onto the crosspiece 1b.

After a predetermined number of semiconductor wafers W are accumulated and stored, the elevator table 2 is lowered to submerge the cassette 1 in which the semiconductor wafers W are stored and stored, and the opening edge portion of the opening surface 1a of the cassette 1 is closed. The lid 1c is closed in a watertight manner in the submerged 1d, and then the cassette 1 is taken out from the water tank portion 4 and the next cassette 1 is set.

The transfer mechanism 3 of the automatic surface grinding machine according to the present invention uses a conveyor belt in addition to the transfer mechanism using the above-mentioned expansion / contraction mechanism, and the elevator table 2 on which the cassette 1 is mounted is also a plurality of cassettes. Equipped with 1 or elevator stand 2
Is a storage mechanism for a semiconductor wafer W and a method thereof that can be applied to a device that can be half-turned in the horizontal direction.

[0022]

As described above, the present invention eliminates the conventionally required drying device, and the semiconductor wafer is stored in the cassette in a submerged state without being dried until it is transferred to the next processing step. There is no trace of evaporation caused by the process, semiconductor wafers can be managed in the liquid until the next process, and the quality can be maintained in a stable state, and the yield of the final product is dramatically improved. Has an extremely significant effect with some immeasurable effects.

[0022]

[Brief description of drawings]

FIG. 1 is a schematic plan view of an embodiment for explaining an automatic surface grinder of the present invention.

FIG. 2 is a side view for explaining an essential part of the next embodiment.

FIG. 3 is a perspective view of a cassette.

[0021]

[Explanation of symbols]

 W Semiconductor wafer 1 Cassette 1a Opening surface 1b Crosspiece 1c Lid 1d Opening edge 2 Elevator stand 3 Transfer mechanism 4 Water tank 5 Rotary table 6 Chuck mechanism 7 Preposition 8 Transfer arm 9 Cleaning device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 21/68 V 8418-4M

Claims (2)

[Claims] 1. An automatic surface grinder that vacuum-sucks a semiconductor wafer onto the upper surface of a chuck mechanism and grinds with a cup wheel grinding wheel at the lower end of a spindle shaft disposed above the chuck mechanism, and has an opening surface on one side. Inside the formed cassette, a plurality of crosspieces partitioned into shelves are provided, an opening edge portion for closing the lid body in a watertight state is provided on the opening surface, and an automatic surface grinder for mounting the cassette. A semiconductor wafer storage mechanism characterized in that a transfer mechanism for storing a semiconductor wafer from the opening surface of the cassette is provided near the elevator table, and at least a water tank portion surrounding the cassette in a submerged state is provided. .. 2. An automatic surface grinder that vacuum-sucks a semiconductor wafer onto the upper surface of a chuck mechanism and grinds it with a cup wheel grinding wheel at the lower end of a spindle shaft disposed above the chuck mechanism. Inside the formed cassette, a plurality of shelves are provided, and an opening edge portion for closing the lid body in a watertight state is provided on the opening surface, and in the vicinity of the elevator table on which the cassette is placed. Is equipped with a transfer mechanism for storing the semiconductor wafer from the opening surface of the cassette, and stores the liquid in the water tank section by using an automatic surface grinder provided with at least a water tank section surrounding the cassette in a submerged state. Then, the cassette is submerged in a substantially submerged state, the semiconductor wafers are integrated and stored in the liquid from the opening surface of the cassette or in the vicinity of the liquid surface, and then the semiconductor wafers are liquid-stored in the cassette. Storage method of a semiconductor wafer, characterized in that both is filled. [0001]