JPH07226432A - Submerged accommodation of semiconductor wafer - Google Patents

Abstract

PURPOSE:To provide a method of accommodating a semiconductor wafer having completed polishing process into a cassette in the accommodation side and simultaneously submerging the wafer into the liquid such as the pure water. CONSTITUTION:There are provided a processing completion work water receiving tank for loading a semiconductor wafer W having completed the polish processing and a water flowing conduit 3 for moving a semiconductor wafer with the water flow arranged between the processing completion work water receiving tank and a cassette in the accommodation side. Moreover, provided are an accommodation side cassette 1 for accommodating one by one the semiconductor wafers having completed the polish processing to the upper surface of respective frame materials 1a provided in the vertical direction with a constant interval, an accommodation side elevator board 5 which is provided to freely go upward and downward with a lifting mechanism 4 for placing the accommodation side cassette 1, an accommodation side warter tank 6 for reserving a liquid for submerging the accommodation side elevator 5 with the accommodation side cassette 1 and a sensor 7 for detecting a semiconductor wafer W accommodated on the frame material 1a of the accommodation side cassette 1 with the water flow of the water flow conduit 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of storing a semiconductor wafer to be a substrate in a storage side cassette after polishing in a manufacturing process of VLSI or the like. The present invention relates to a storage method in which a processed surface is stored in a storage-side cassette without leaving traces of water droplets such as stains or cloudiness and at the same time submerged in a liquid such as pure water.

BACKGROUND OF THE INVENTION

This type of semiconductor wafer according to the present invention is used in electronic circuits such as computers and integrated circuits such as OA equipment, and its development is advancing day by day, and it is extremely thin due to the miniaturization of the equipment itself. And the quality of super high precision,
From the viewpoint of workability, there is a demand for further diameter expansion.

Further, these semiconductor wafer devices are
With higher density and higher integration, the production of ultra LSI (ULSI) of 64 megabytes or more has become necessary, and in recent years, development of ultra LSI of 256 megabyte or 1 gigabyte has been started. .

A wiring layer (metal film), an insulating film (oxide film or the like) or a polysilicon film (semiconductor film) is formed as a multilayer film on the surface of these semiconductor devices.
In other words, the LSI has a single-layer structure, whereas the VLSI has a two-layer structure and a three-layer structure. In the manufacturing process, each layer is provided with ultra-high precision flatness and clean mirror surface. Need to have processing.

[0005]

2. Description of the Related Art In the processing of semiconductor wafers such as fully automatic polishing machines, most of the steps are usually performed in the atmosphere, but cleaning and alignment before polishing, cooling water, or after processing Pure water is used for cleaning the
Immediately before storing in a storage cassette, liquid such as pure water was removed by a centrifugal separator or the like, but small water droplets or the like were often attached.

[0006]

However, the semiconductor wafers required these days have a high quality mirror finish without contamination, and even if they are polished with high precision and flatness by polishing.
After the attached water droplets have evaporated, the traces of the water droplets stain or cloud on the mirror-finished surface, which is a factor that reduces the yield of the final product.

[0007]

DISCLOSURE OF THE INVENTION In view of the above problems, the method of submerging a semiconductor wafer in water according to the present invention has been earnestly studied. The purpose is to solve the above-mentioned problems by providing a method of submerging in water.

[0008]

The structure of the polishing machine used in the present invention is as follows.
Finished work water receiving tank for mounting the semiconductor wafer after polishing, a water flow trough that is arranged between the finishing work water receiving tank and the storage side cassette and moves the semiconductor wafer by a water flow, and the semiconductor wafer after polishing And a storage-side cassette that stores each of the individual products on the upper surface of each crosspiece provided at a constant interval in the vertical direction, and a storage-side elevator stand that is mounted on the storage-side cassette and is vertically movable by an elevating mechanism. A storage-side water tank that stores a liquid for submerging the storage-side elevator base together with the storage-side cassette, and a sensor that detects a semiconductor wafer stored on the crosspiece of the storage-side cassette by the water flow of the water flow gutter Is.

[0009]

The function of the present invention is to place the semiconductor wafer after polishing on the machining-completed work water receiving tank, and to place the semiconductor wafer in the machining-completed work water receiving tank on the crosspiece of the storage side cassette by the water flow of the water flow gutter. The semiconductor wafer is detected by a sensor, the elevating mechanism is operated by the detection of the sensor, the storage cassette is lowered to one stage of the crosspiece, and the cassette is submerged in the liquid in the storage tank.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for submerging a semiconductor wafer in water according to the present invention will be described with reference to the drawings of the embodiments.

FIG. 1 is a schematic plan view of a fully automatic polishing machine for explaining an embodiment of the present invention, and FIG. 2 is a side view of a main portion of the present invention.

According to the present invention, a storage side cassette 1 is provided after polishing a semiconductor wafer to be a substrate in a manufacturing process of VLSI or the like.
It is related to the method of storing in
The present invention relates to a storage method in which a semiconductor wafer W after processing is stored in a storage side cassette 1 without leaving traces of water droplets such as stains or cloudiness on the processed surface and at the same time submerged in a liquid A such as pure water. Completion work water receiving tank 2 on which the semiconductor wafer W is mounted, a water flow trough 3 arranged between the machining completion work water receiving tank 2 and the storage side cassette 1 to move the semiconductor wafer W by water flow, and polishing A storage-side cassette 1 for storing the subsequent semiconductor wafers W individually on the upper surface of each crosspiece 1a provided at a certain interval in the vertical direction, and the storage-side cassette 1 is placed and moved up and down by an elevating mechanism 4. A storage-side elevator stand 5 that is freely provided, a storage-side water tank 6 that stores the liquid A that submerges the storage-side elevator stand 5 together with the storage-side cassette 1, and the storage-side cassette 1 Using the sensor 7 for detecting the semiconductor wafer W accommodated by the water flow of the water flow gutter 3 on the crosspiece 1a, the semiconductor wafer W after polishing is mounted on the processing completion work water receiving tank 2 and the processing completion work is performed. The semiconductor wafer W in the water receiving tank 2 is stored on the crosspiece 1a of the storage-side cassette 1 by the water flow of the water flow trough 3, and the semiconductor wafer W is detected by the sensor 7, and the lifting mechanism 4 is operated by the detection of the sensor. The storage-side cassette 1 is lowered to one stage of the crosspiece 1a and submerged in the liquid A in the storage-side water tank 6.

That is, the present invention provides a semiconductor wafer W after being processed by a fully-automatic polishing apparatus capable of sufficiently supporting the recent demands for extremely thin semiconductor wafer W, enlargement of diameter, and ultra-precision flat surface processing. The present invention relates to a method of submerging and accommodating the storage-side cassette 1 in water, and a fully automatic polishing apparatus for carrying out the present invention is shown in FIG.

The semiconductor wafer W before polishing has its outer peripheral edge portion supported by a plurality of horizontal bars formed horizontally at regular intervals in the vertical direction of the box-shaped supply side cassette 11 with the pattern surface as the lower surface. It is stored in.

The supply-side cassette 11 is placed on a supply-side elevator base 12 which can be raised and lowered, and the height of the supply-side cassette 11 is adjusted by an elevating mechanism 13 such as a screw shaft of the supply-side elevator base 12. It is chucked by and sent out.

The contactless float chuck 14 is attached to the tip of a three-axis robot 15, and the three-axis robot 15 is slidable in the direction of the supply side cassette 11 by a uniaxial servo slide unit 16 as shown in the figure. It is provided.

That is, the 1-axis servo slide unit 16
And the chuck of the non-contact float chuck 14 carry out the semiconductor wafer W from the cassette 11 on the supply side, and the triaxial robot 15 inverts the front and back and horizontally rotates and transfers it to the cleaning tank shift device 17. It is something.

Then, the cleaning tank slide unit 18 moves the cleaning tank shift device 17 to the cleaning tank 19 to clean the polished surface of the semiconductor wafer W by a polishing surface cleaning device (not shown) such as a brush, and after cleaning, the cleaning tank. It is moved again to the shift device 17.

The semiconductor wafer W is attracted to the suction plate on the lower surface of either the first work spindle 20 or the second work spindle 21 and is moved to the polish table 23 by the rotation of the indexing table 22. The polishing process is performed by sandwiching the polishing cloth with the polishing cloth stretched on the polishing table 23.

The index table 22 has a first work spindle 20 and a second work spindle 21 arranged at opposite positions, and a polish table cleaning brush 24 and a balance weight 25 arranged at right angles to each other. A rotating mechanism (not shown)
Thus, it is intermittently rotated in the direction of 180 degrees or 90 degrees.

The semiconductor wafer W after the polishing process is moved to the processing completed work receiving tank 2 while being adsorbed to the adsorption plate of either the first work spindle 20 or the second work spindle 21, where the adsorption is released and the wafer is processed. The finished work water receiving tank 2 is placed on the completed work water receiving tank 2.
The liquid A, such as pure water, is made to flow into the water flow gutter 3 arranged between the storage-side cassette 1 and the storage-side cassette 1 so that the water flow causes the liquid A to move to the upper surface to the crosspiece 1a of the storage-side cassette 1.

On the other hand, the storage-side cassette 1 is provided with a large number of crosspieces 1a at regular intervals in the vertical direction, and the storage-side cassette 1 is provided so as to be vertically movable by an elevating mechanism 4 such as a screw shaft 4a. It is placed on the storage side elevator stand 5,
The screw shaft 4a is rotated by a drive source 4b such as an electric motor to move up and down the storage-side cassette 1 together with the storage-side elevator stand 5.

A liquid A such as pure water is stored in the storage side water tank 6, and a sufficient amount of water is stored so that the storage side elevator base 5 and the storage side cassette 1 can be submerged.

A sensor 7 is provided for detecting the semiconductor wafer W of each individual product housed by the water flow of the water flow gutter 3. The sensor 7 detects the semiconductor wafer W of each individual product and drives the drive source 4b. Although it is driven, a photoelectric switch, a contact switch, or the like may be used as the sensor 7, and the drive source 4b is electrically or mechanically driven for a fixed time to reduce the amount of fall of the crosspiece 1a of the storage-side cassette 1. It can be set to a fixed interval.

[0025]

As described above, the present invention eliminates the centrifuge which has been conventionally required, and allows the semiconductor wafer to be stored in the storage side cassette in a submerged state without being dried until the next processing step. In addition, there are no traces of evaporation due to water droplets, semiconductor wafers can be managed in a liquid until the next process, quality can be maintained in a stable state, and the yield of the final product is dramatically improved. The degree of contribution has a very significant effect, which is immeasurable.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a fully automatic polishing machine for explaining an embodiment of the present invention.

FIG. 2 is a side view for explaining a main part of the present invention.

[Explanation of symbols]

 W Semiconductor wafer A Liquid 1 Storage side cassette 1a Crosspiece 2 Work completion work water receiving tank 3 Water flow trough 4 Lifting mechanism 5 Storage side elevator stand 6 Storage side water tank 7 Sensor 11 Supply side cassette 12 Supply side elevator stand 13 Lifting mechanism 14 Non-contact Float chuck 15 3-axis robot 16 1-axis servo slide unit 17 Cleaning tank shift device 18 Cleaning tank slide unit 19 Cleaning tank 20 First work spindle 21 Second work spindle 22 Indexing table 23 Polish table 24 Polish table cleaning brush 25 Balance weight

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B65D 85/86

Claims (1)

[Claims] 1. A processed water receiving tank on which a semiconductor wafer after polishing is mounted, and a water gutter which is arranged between the processed water receiving tank and a storage side cassette to move the semiconductor wafer by water flow. A storage-side cassette that stores the polished semiconductor wafers individually on the upper surface of each crosspiece provided at a constant interval in the vertical direction, and the storage-side cassette is placed so that it can be raised and lowered by an elevating mechanism. A storage-side elevator table, a storage-side water tank that stores a liquid that submerges the storage-side elevator table together with the storage-side cassette, and a semiconductor wafer stored by a water flow trough on the crosspiece of the storage-side cassette. Using the sensor for detecting, the semiconductor wafer after polishing is placed on the processing-completed work water receiving tank, and the semiconductor wafer in the processing-completed work water receiving tank is put into a water gutter. It is stored on the crosspiece of the storage-side cassette by the flow of water, and the semiconductor wafer is detected by a sensor, and the raising / lowering mechanism is operated by the detection of the sensor to lower the storage-side cassette to one step of the crosspiece and in the storage-side water tank The method of submerging a semiconductor wafer in water, characterized by immersing the semiconductor wafer in water.