JPH0217300B2 - - 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 chuck mechanism with 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 sent back to float the semiconductor wafer. However, air jets alone cannot sufficiently remove fine particles such as grinding debris that adhere to the top surface of the platform, etc. They remain on the top surface of the mounting table, and if the semiconductor wafer is of normal thickness, there will be almost no problems such as distortion or damage to the top surface of the semiconductor wafer even if some fine particles remain and are vacuum-adsorbed. It did not occur.

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 surface tension of the liquid adhering to the top surface of the chuck mechanism, and since grinding is performed at high speeds, 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.
The jetting water is temporarily accumulated between these chuck mechanisms, and the amount of water that destroys the surface tension of the static water penetrates the platform made of porous material and is jetted onto the top surface. The object of the present invention is to provide a method for removing a semiconductor wafer by causing the entire lower surface of the semiconductor wafer to float evenly, attracting the semiconductor wafer with a suction pad provided at the tip of the transfer arm, and raising the transfer arm by slightly shifting the transfer arm in the horizontal direction.

[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. 2 shows a state in which a semiconductor wafer is levitated by a water flow. FIG. 3 is an explanatory diagram showing a state in which the suction pad of the transfer arm is used to adsorb the product, and FIG. 4 is an explanatory diagram showing the product being slightly shifted in the horizontal direction by the transfer arm.

The present invention provides a chuck mechanism 1 of a grinding machine etc.
Regarding the method of removing the brittle and ultra-thin semiconductor wafer A from the chuck mechanism 1, a transfer arm 6 having a suction pad 8 at the tip 7 and capable of rotating horizontally and moving back and forth is moved up and down on the upper side of the chuck mechanism 1. At the same time, the chuck mechanism 1 is provided with a cylindrical recess 2.
A spacer 5 is provided at the bottom of the recess 2, and a disk-shaped platform 4 made of a porous material is rotatably fixed to the shaft, and an exhaust port passing through the center of the shaft is provided. The chuck mechanism 1 having a vacuum suction function is used to grind the ultra-thin semiconductor wafer A provided with the water inlet 3, and the ultra-thin semiconductor wafer A after the grinding process is placed on the mounting table 4. At the same time as the vacuum adsorption of the water is released, water is jetted from the water inlet 4 to temporarily accumulate in the spacer 5, and the amount of water is enough to destroy the surface tension of the water layer that forms on the top surface of the platform 4 in a static state. The water permeates the mounting table 4 made of a porous material and is jetted onto the upper surface of the mounting table 4 to remove the semiconductor wafer A.
In this method, the semiconductor wafer A is removed by causing the entire lower surface of the semiconductor wafer A to float evenly and attracting it with a suction pad 8 provided at the tip 7 of the transfer arm 6, and then raising the transfer arm 6 while slightly shifting it in the horizontal direction.

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 gap portion 5 having an appropriate volume is provided between the lower surface of the disk-shaped platform 4 made of a porous material such as porous ceramic, and the platform 4 is formed by means of forming a step. The shaft is rotatably fixed on a shaft, and an exhaust port and water inlet 3 is provided passing through the center of the shaft.
The exhaust port/water inlet 3 is connected to a vacuum pump and a water pump through the chuck mechanism 1, and the chuck mechanism has the function of vacuum suctioning the ultra-thin semiconductor wafer A by moving the vacuum pump and applying a load. 1, and a transfer arm 6 provided on the upper side of the chuck mechanism 1 with a suction pad 8 at its tip 7 and capable of rotating in the horizontal direction and moving back and forth in the horizontal direction.

When the vacuum suction of the ultra-thin semiconductor wafer A placed on the mounting table 4 after grinding is released, and at the same time, the water pump is operated to jet water from the exhaust port/water inlet 3, the water is discharged. While the water has a certain volume, it temporarily accumulates in the bottom part 5, and when water continues to be fed, the water fills the bottom part 5, and a large amount of water suddenly accumulates on the platform made of a porous material such as porous ceramic. 4 is permeated into the upper surface of the mounting table 4, and a sufficient amount of water is jetted to break the surface tension of the water layer formed in a stationary state on the upper surface of the mounting table 4, and the entire lower surface of the semiconductor wafer A is jetted. While floating evenly depending on the amount of water, in addition, the transfer arm 6
The ultra-thin semiconductor wafer is removed by adsorbing it with a suction pad 8 provided at the tip 7 of the semiconductor wafer, and then moving it slightly horizontally and raising the transfer arm 6 to further weaken the suction effect caused by surface tension. The semiconductor wafer A can be removed without damage, and the lower surface of the semiconductor wafer A and the upper surface of the chuck mechanism 1, such as the mounting table 4, are washed and cleaned with a large amount of water, and at the same time, the frictional heat caused by the grinding is cooled down.

In this way, a sufficient amount of water is jetted to destroy the surface tension of the water layer formed in a stationary state,
By slightly shifting the wafer A in the horizontal direction and removing it using the transfer arm 6, the semiconductor wafer A can be removed safely and reliably without being affected by the adsorption effect of the liquid, and without wasting time. In addition, this is a removal method in which the removed semiconductor wafer A is cleaned by a water stream and further cooled without storing frictional heat caused by grinding, and after the removed semiconductor wafer A is transferred to another system device, the following steps are performed. The unground semiconductor wafer A is efficiently and thoroughly cleaned, and the frictional heat is removed from the chuck mechanism 1.
The vacuum suction is applied to the upper surface of the material, and the material can be sequentially ground.

〔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 levitated by a water flow. Third
The figure is an explanatory diagram of a state in which the suction pad of the transfer arm is suctioned. FIG. 4 is an explanatory view of the device slightly shifted horizontally by the transfer arm. A...Semiconductor wafer. 1...chuck mechanism, 2...recess, 3...exhaust port and water inlet, 4...mounting platform, 5...space〓
Part, 6... Transfer arm, 7... Tip part, 8... Suction part.

Claims (1)

[Scope of Claims] 1. A transfer arm is provided on the upper side of the chuck mechanism that has a suction pad at its tip and can rotate horizontally and move forward and backward, and is movable up and down, and the chuck mechanism is provided with a cylindrical recess. A space was provided at the bottom of the recess to rotatably fix a disc-shaped platform made of a perforated material on a shaft, and an exhaust port and water inlet was provided passing through the center of the shaft. In order to grind an ultra-thin semiconductor wafer, a chuck mechanism having 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 open the water inlet. A jet of water is made to temporarily accumulate in the gap, and an amount of water that breaks the surface tension of the water layer that forms on the top surface of the platform in a static state penetrates the platform made of porous material. Then, the entire lower surface of the semiconductor wafer is evenly floated by a jet on the top surface of the mounting table, and the semiconductor wafer is adsorbed by the suction pad provided at the tip of the transfer arm, and the transfer arm is slightly shifted horizontally and raised to remove it. A method for removing a semiconductor wafer from a chuck mechanism, characterized in that: