JP2000277476A - Semiconductor wafer cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a semiconductor wafer itself or wirings or the like formed on the wafer against damage caused by static electricity, by a method where static electricity induced when contaminants attached to the surface of a semi conductor wafer as a work are removed by spouting out liquid droplets against the wafer is grounded. SOLUTION: Droplets 5 are sprayed on the surface of a semiconductor wafer 7 as a work to remove contaminants attached to the wafer 7. In this case, rinsing pure water 9 where carbon dioxide gas is dissolved is sprayed on the rear surface of the wafer 7, by which a current flowing from the charged droplets 5 to the wafer 7 is grounded outside through the rinsing pure water 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer cleaning apparatus, and more particularly to a semiconductor wafer cleaning apparatus capable of cleaning a semiconductor wafer while removing harmful static electricity.

[0002]

2. Description of the Related Art Droplets composed of a cleaning liquid such as pure water, fine ice particles, and an organic solvent are jetted at high speed toward the surface of a semiconductor wafer to be cleaned to remove contaminants adhering to the surface. Semiconductor wafer cleaning apparatuses are widely used in semiconductor manufacturing processes. FIG. 1 shows a conventional representative example of this semiconductor wafer cleaning apparatus, in which a semiconductor wafer 7 to be cleaned is fixed to chuck pins 6. Rotational movement is performed while holding fixed. On the other hand, the injection nozzle 1 is located above the chuck pin 6.
The cleaning nozzle 1 is connected to a cleaning liquid introduction pipe 2 for supplying a cleaning liquid 15 to the injection nozzle 1 and a carrier gas introduction pipe 3 for supplying a carrier gas 14 to the injection nozzle 1. The droplets 5 accelerated by the carrier gas 14 are ejected from the ejection nozzle 1 toward the semiconductor wafer 7. In addition, as the cleaning liquid 15, pure water, fine ice particles, an organic solvent, or the like is used. The spray nozzle 1 performs a cleaning operation while moving from the center to the outer periphery of the semiconductor wafer 7 being rotated.

[0003]

At this time, the injection nozzle 1, the cleaning liquid introduction pipe 2, and the carrier gas introduction pipe 3 are all often made of a fluororesin such as Teflon (trade name). Since the carrier gas 14 is electrically nonconductive, static electricity is generated even if the carrier gas 14 flows through the carrier gas introduction pipe 3, and the carrier gas 14 is charged. Therefore, the cleaning liquid 15 such as pure water mixed with the carrier gas 14 is also charged in the ejection nozzle 1, and as a result, the charged droplet 5 collides with the semiconductor wafer 7 from the ejection nozzle 1. Become.

In addition, static electricity is generated not only by friction between the carrier gas 14 and the carrier gas introduction pipe 3 but also at the moment when the droplet 5 is ejected from the ejection nozzle 1, and the droplet is ejected from the ejection nozzle 1. At the moment when the droplet 5 separates, the droplet 5 itself is also charged due to the separation charging phenomenon. As described above, in the wafer cleaning apparatus that ejects the droplets 5 to remove the contaminants attached to the surface of the semiconductor wafer 7, the generation of static electricity is an unavoidable phenomenon.

On the other hand, the chuck pins 6 for holding the semiconductor wafer 7 are also usually made of fluorine resin, and in this case, the semiconductor wafer 7 is electrically insulated. When the droplet 5 is ejected onto the semiconductor wafer 7, the static electricity is not grounded, so that a high voltage is instantaneously applied to the surface of the semiconductor wafer 7 and seriously damages the wiring formed on the surface. Severe electrical damage.

Further, a flammable liquid such as an organic solvent is
When used as 5, there was a risk of ignition or explosion due to discharge of static electricity. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems caused by static electricity during a semiconductor wafer cleaning operation. A new semiconductor wafer cleaning device that allows the generated static electricity to be grounded when removing the semiconductor wafer and does not damage the semiconductor wafer itself or the wiring formed thereon by the static electricity It is something you want to do.

[0007]

According to the present invention, there is provided a semiconductor wafer cleaning apparatus for jetting a droplet 5 toward a surface of a semiconductor wafer 7 to be cleaned to remove contaminants adhering to the surface. Rinsing pure water 9 in which carbon dioxide gas is dissolved is sprayed toward the back surface of the semiconductor wafer 7 so that the current flowing from the charged droplet 5 to the semiconductor wafer 7 is grounded to the outside through the rinsing pure water 9. In addition, if a soft X-ray irradiating device for irradiating the soft X-ray from above toward the semiconductor wafer 7 during the cleaning operation is provided, the static electricity can be more effectively removed. .

[0008]

An embodiment of the present invention will be described with reference to FIG. In the figure, reference numeral 6 denotes a chuck pin for fixing and holding a semiconductor wafer 7 to be cleaned, which rotates while holding the semiconductor wafer 7. On the other hand, reference numeral 1 denotes a spray nozzle located above the semiconductor wafer 7 and is directed in the direction of the semiconductor wafer 7.
A cleaning liquid introduction pipe 2 and a carrier gas introduction pipe 3 are connected to the injection nozzle 1, and a cleaning liquid 15 and a carrier gas 14 are passed through the introduction nozzles 2 and 3.
And ejected from the ejection nozzle 1 as droplets 5 toward the semiconductor wafer 7 at high speed.

As the cleaning liquid 15, pure water is usually used, but fine ice particles or an organic solvent may be used.
Here, the cleaning liquid 15 includes these fine ice particles and an organic solvent in addition to pure water. In addition, injection nozzle 1
Is configured to eject the droplets 5 while moving from the center of the semiconductor wafer 7 to the outer periphery. The above configuration is basically the same as a conventional semiconductor wafer cleaning apparatus.

On the other hand, a grounding nozzle 8 is positioned on the backside of the semiconductor wafer 7 so as to face the backside of the semiconductor wafer 7, and a pure water introduction pipe 10 is connected to the grounding nozzle 8, Rinse pure water 9 can be sprayed toward the back surface of the wafer 7. Further, a carbon dioxide gas bubbler 12 is provided in the middle of the pure water introduction pipe 10 so that the carbon dioxide gas is dissolved in the rinse pure water 9.

Further, a metal needle 1 is provided in the pure water introduction pipe 10 between the carbon dioxide bubbler 12 and the ground nozzle 8.
The other end of the metal needle 11 is pulled out of the tube and grounded. On the other hand, a soft X-ray irradiator 13 is positioned above the semiconductor wafer 7 so that the soft X-ray is irradiated toward the semiconductor wafer 7.

In this embodiment, the chuck pins 6 holding the semiconductor wafer 7 start to rotate, and at the same time, the rinsing is performed from the ground nozzle 8 toward the back surface of the semiconductor wafer 7. Pure water 9 is sprayed. Thereafter, the droplets 5 accelerated from the ejection nozzle 1 are ejected toward the semiconductor wafer 7 to remove contaminants on the surface thereof. An electric current flows through the wafer 7, and the electric current flows through the rinse pure water 9 sprayed on the back surface of the wafer 7, and is grounded to the outside through a metal needle 11 inserted into a pure water introduction pipe 10.

At this time, a carbon dioxide gas bubbler 12 is provided on the upstream side of the metal needle 11 so that the carbon dioxide gas is sufficiently dissolved in the rinse pure water 9. The carbon dioxide gas increases the current, and the current flows more easily. In addition, soft X-rays 16 are emitted from the soft X-ray irradiator 13 toward the jetted droplets 5, and a part of the droplets 5 is discharged by the soft X-rays 16.

[0014]

As described above, according to the semiconductor wafer cleaning apparatus of the present invention, it is possible to effectively remove the static electricity generated when the cleaning liquid droplets are ejected, and to clean the semiconductor wafer to be cleaned and its semiconductor wafer. This has the effect that the cleaning operation can be performed without causing electrical damage to the wirings and the like formed thereon. In addition, when a flammable liquid such as an organic solvent is used as the cleaning liquid, the danger of ignition and explosion due to electrostatic discharge can be eliminated, and the cleaning operation can be performed safely. Things.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a typical example of a conventional semiconductor wafer cleaning apparatus.

FIG. 2 is an explanatory view of one embodiment of a semiconductor wafer cleaning apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection nozzle 2 Cleaning liquid introduction pipe 3 Carrier gas introduction pipe 5 Droplet 6 Chuck pin 7 Semiconductor wafer 8 Grounding nozzle 9 Rinse pure water 10 Pure water introduction pipe 11 Metal needle 12 Carbon dioxide gas bubbler 13 Soft X-ray irradiation device 14 Carrier gas 15 Cleaning liquid 16 Soft X-ray

Claims (2)

[Claims] 1. A semiconductor wafer cleaning apparatus for ejecting a droplet 5 toward a surface of a semiconductor wafer 7 to be cleaned and removing contaminants adhering to the surface of the semiconductor wafer 7. A semiconductor wafer characterized in that rinsing pure water 9 in which carbon dioxide gas is dissolved is jetted, and a current flowing from the charged droplet 5 to the semiconductor wafer 7 is grounded to the outside through the rinsing pure water 9. Cleaning equipment. 2. The semiconductor wafer cleaning apparatus according to claim 1, further comprising a soft X-ray irradiator 13 for irradiating the semiconductor wafer 7 being cleaned with soft X-rays 16 from above.