JPH0582053B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for removing a brittle and extremely thin semiconductor wafer from a chuck mechanism such as a grinding machine.

[Background of the invention]

This type of semiconductor wafer according to the present invention is used in integrated circuits of electronic related equipment such as computers, so-called OA equipment, etc., and the development thereof is progressing day by day, and as the equipment itself becomes smaller,
From the viewpoint of ultra-thinness, ultra-high precision quality, and workability, there is a demand for further diameter expansion.

[Prior art and its problems]

In a conventional mounting platform made of a perforated material with a chuck mechanism that has a vacuum suction function, such as a conventional grinder, the semiconductor wafer is first vacuum suctioned and ground, and after the grinding process, the vacuum suction is released and air is released. The semiconductor wafer is transported backwards and floated, and the suction pad adsorbs it, lifting the transfer arm to peel it off. Foreign matter cannot be removed sufficiently and remains on the top surface of the mounting table, etc. If the semiconductor wafer is of normal thickness, some fine foreign matter remains and the top surface of the semiconductor wafer may be distorted even if vacuum suction is applied. No problems such as damage occurred.

However, with the ultra-thin semiconductor wafers that are in demand these days, even if there is a slight amount of grinding debris or other fine particles remaining on the top surface of the chuck mechanism's mounting table, the ultra-thin semiconductor wafers are brittle and may break if vacuum suction is applied. When the semiconductor wafer itself is distorted by fine particles and the top surface to be ground cannot be flat, or when the mirror-finished top surface of the semiconductor wafer after grinding is picked up by a suction pad and peeled off from the top surface of the chuck mechanism. Semiconductor wafers are frequently damaged due to the suction effect caused by the surface tension of the liquid that adheres to the top surface of the chuck mechanism.Furthermore, since grinding is performed at high speed rotation, damage to semiconductor wafers is caused by frictional heat. Various problems have arisen, such as:

For this reason, a method has been adopted in which a separate cleaning device is used for cleaning each time after each grinding process, but this involves a large loss of time.

[Purpose of the invention]

The present invention was developed as a result of intensive research in view of the above reasons.
Water containing a large amount of microbubbles is temporarily accumulated in the space between these chuck mechanisms, and the water containing a large amount of microbubbles is transferred to a tube made of a porous material that destroys the surface tension of water in a stationary state. It is an object of the present invention to provide a method for removing a semiconductor wafer by causing a suction pad provided on a transfer arm to attract the semiconductor wafer while uniformly floating the entire lower surface of the semiconductor wafer by permeating the mounting table and causing a jet to flow onto the upper surface of the wafer, thereby raising the transfer arm.

[Embodiments of the invention]

An embodiment of the method for removing a semiconductor wafer in a chuck mechanism of a grinding machine or the like according to the present invention, which achieves the above object, will be described below with reference to the drawings.

FIG. 1 is a schematic explanatory diagram showing the main components of a part of the main body of a chuck mechanism of a grinding machine or the like according to the present invention, and FIG. FIG. 2 is a schematic explanatory diagram showing a floating state of a wafer.

The present invention provides a chuck mechanism 1 of a grinding machine etc.
Regarding the method for removing the brittle and ultra-thin semiconductor wafer A from the chuck mechanism 1, a transfer arm equipped with a suction pad at the tip is provided on the upper side of the chuck mechanism 1 so as to be able to move up and down, and a cylindrical recess is attached to the chuck mechanism 1. A spacer 5 is provided on the bottom surface of the recessed part 2, and a disc-shaped platform 4 made of a porous material is rotatably fixed on the shaft, and an exhaust gas is provided through the center of the shaft. In order to grind an ultra-thin semiconductor wafer A provided with a spout/water inlet 3, the chuck mechanism 1 having a vacuum suction function is used to place the ultra-thin semiconductor wafer A after grinding on the mounting table 4. At the same time as releasing the vacuum adsorption of wafer A, the exhaust port/water inlet 3
A jet of water containing a larger amount of fine air bubbles is caused to temporarily accumulate in the intermediate portion 5, and a large amount of fine air bubbles are generated on the upper surface of the platform 4, destroying the surface tension of the water layer formed in a static state. The contained water permeates the mounting table 4 made of a porous material, and is jetted onto the upper surface of the mounting table 4 to evenly levitate the entire lower surface of the semiconductor wafer A, while being sucked by a suction pad provided on the transfer arm. In this method, the transfer arm is removed by lifting the transfer arm.

That is, as shown in FIG. 1, the apparatus for carrying out the present invention has a chuck mechanism main body 1 of a grinding machine or the like formed with a recess 2 having a cylindrical shape and a flat bottom. A spacer portion 5 having an appropriate volume is provided between the lower surface of the platform 4 made of a porous material such as porous ceramic, and the disk-shaped platform 4 is used as a means for forming a stepped portion. Therefore, the bearing is fixed so that it can rotate freely,
An exhaust port/water inlet 3 is provided that passes through the center of the shaft, and the exhaust port/water inlet 3 passes through the chuck mechanism 1 and is connected to a vacuum pump and a water pump. A chuck mechanism 1 having a vacuum suction function for vacuum-chucking an ultra-thin semiconductor wafer A under a load, and a transfer arm (not shown) equipped with a suction pad at the tip on the upper side of the chuck mechanism 1 are used. This will be carried out in accordance with the above.

At the same time, the vacuum suction of the ultra-thin semiconductor wafer A placed on the mounting table 4 made of a porous material after grinding is released, and at the same time, a water pump is operated from the exhaust port/water inlet 3 to remove a large amount of fine particles. When water containing air bubbles is jetted, the water containing fine air bubbles temporarily accumulates in the bottom part 5 while it has a volume, and when the water continues to be fed, the water containing a large amount of air bubbles remains. The water that fills the intermediate part 5 and contains a large amount of fine air bubbles at once permeates the platform 4 made of a porous material and is jetted onto the top surface of the platform 4, forming a static water layer on the top surface of the platform 4. This is a jet of water containing a sufficient amount of fine air bubbles to break the surface tension of the material, and the large amount of fine air bubbles that have permeated the platform 4 made of the porous material and a sufficient amount of water to jet out. The surface tension can be easily broken by this, and in addition, while the entire lower surface of the semiconductor wafer A is evenly floated by the fine bubbles and water,
By adsorbing it with a suction pad provided on the transfer arm and lifting the transfer arm to remove it, the ultra-thin semiconductor wafer A can be removed without damage, and the bottom surface of the semiconductor wafer A and the top surface of the chuck mechanism 1 can be removed. The water washes away the material and at the same time cools down the frictional heat caused by grinding.

In this way, the semiconductor wafer A is removed by jetting a large amount of fine bubbles and a sufficient amount of water to easily destroy the surface tension of the water layer that is formed in a static state, so the semiconductor wafer A is safely and reliably removed without any loss of time. This is a removal method in which the top surfaces of the chuck mechanism 1 and the mounting platform 4 are cleaned by a stream of water, and are cooled without accumulating frictional heat caused by grinding. After the wafer A is transferred to another system device, the next unground semiconductor wafer A is vacuum-adsorbed onto the upper surface of the chuck mechanism 1, which has been efficiently and sufficiently cleaned and freed from frictional heat, and can be sequentially ground. It is something.

〔Effect of the invention〕

As described above, the present invention not only enables removal of the semiconductor wafer after grinding without wasting time and without causing any damage to the mirror surface of the semiconductor wafer, but also cleans the bottom surface of the semiconductor wafer and the top surface of the chuck mechanism, and then grinds the semiconductor wafer at the same time. Its contribution is immeasurable, and it has extremely significant effects.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing the main components of a part of a chuck mechanism main body of a grinding machine or the like according to the present invention. FIG. 2 is a schematic explanatory diagram showing a state in which a semiconductor wafer is floated by a water flow. A...Semiconductor wafer. 1...Chuck mechanism, 2
... Recessed part, 3... Exhaust port/water inlet, 4... Mounting platform, 5... Interval part.

Claims (1)

[Scope of Claims] 1. A transfer arm equipped with a suction pad at the tip is provided on the upper side of the chuck mechanism so as to be able to move up and down, and a cylindrical recess is formed in the chuck mechanism, and a cylindrical recess is formed on the bottom surface of the recess. A disk-shaped platform made of a porous material is rotatably fixed on a shaft with a space between the two, and an ultra-thin semiconductor wafer is ground with an exhaust port and water inlet passing through the center of the shaft. In order to do this, a chuck mechanism with a vacuum suction function is used to release the vacuum suction of the ultra-thin semiconductor wafer placed on the mounting table after grinding, and at the same time, a large amount of fine air bubbles are removed from the exhaust port/water inlet. Water contained in the porous material is jetted to temporarily accumulate in the space, and the water containing a large amount of microbubbles that destroys the surface tension of the water layer formed in a static state on the top surface of the platform is removed from the porous material. The semiconductor wafer is penetrated through the loading platform, and is jetted onto the upper surface of the loading platform to evenly levitate the entire lower surface of the semiconductor wafer, and the semiconductor wafer is adsorbed by a suction pad provided on the transfer arm, and the transfer arm is raised to remove the semiconductor wafer. A method for removing a semiconductor wafer from a chuck mechanism.