JPH05217980A - Foreign matter removing method - Google Patents

Abstract

PURPOSE:To remove a foreign matter, adhered to a wafer, easily without providing a semiconductor device, formed on the wafer, with any damage. CONSTITUTION:A wafer 10 is put on a moving stage 3 to inspect foreign matters by a microscope 2 while moving the moving stage 3. When a foreign matter 11 on the wafer 10 is found during inspection, the objective lens of the microscope is moved upwardly and a suction nozzle 1, equipped with an air intercepting valve, is made to approach the foreign matter 11. In this case, the air intercepting valve is closed. Then, the air intercepting valve is opened and airstream toward the suction nozzle is generated whereby the foreign matter 11 is sucked and removed by the suction nozzle 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of removing foreign matter such as minute dust adhering to a wafer or broken pieces of resist in the process of manufacturing a semiconductor device, and the foreign matter is mixed in the semiconductor device to cause defective products. Is to prevent the occurrence of.

[0002]

2. Description of the Related Art Foreign substances adhering to a wafer are found by a microscope or a foreign substance inspection device. Conventionally, when a foreign substance was found, the entire wafer was cleaned, but it was not possible to prevent the foreign substance from reattaching to the wafer. That is, there was no effective method for removing foreign matter. However, in recent years, there has been proposed a method of irradiating foreign matter with charged particles to charge the foreign matter, and then bringing the member charged with an electric charge opposite to that of the foreign matter close to the foreign matter and adsorbing the foreign matter to the member to remove the foreign matter. There is.

[0003]

However, in such a foreign matter removing method, there is a possibility that the semiconductor device is damaged when the charged particles are irradiated. In addition, it is necessary to install complicated and expensive accessory devices such as a charged particle irradiation device and a foreign matter removing member in the semiconductor device manufacturing apparatus.

The present invention has been made in view of the above,
It is an object of the present invention to provide a method for easily removing a foreign substance found in the process of manufacturing a semiconductor device without damaging the semiconductor device.

[0005]

In a foreign matter removing method according to the present invention, in a process of manufacturing a semiconductor device, a foreign matter attached to a wafer is brought into proximity with a suction nozzle connected to a vacuum source via an airtight hose to suck the foreign matter. The air shutoff valve provided in the nozzle is opened to generate an air flow toward the suction nozzle to suck and remove foreign matter from the wafer.

[0006]

By sucking the foreign matter adhering to the wafer surface, the foreign matter can be removed without damaging the semiconductor device.

[0007]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4 show an inspection unit in the foreign matter inspection apparatus. Here, as the vacuum source and the airtight hose, the vacuum source (vacuum pump) for the vacuum tweezers used for wafer transfer and the airtight hose can be used as they are, so they are not shown.

FIG. 1A, FIG. 1B and FIG. 1C
Shows a first embodiment of the present invention. Figure 1
As shown in (A), the wafer 10 is placed on the moving stage 3 which can be freely moved in the horizontal and vertical directions. The microscope 2 inspects foreign matters on the wafer while moving the moving stage 3 in the horizontal direction.

When a foreign substance 11 on the wafer 10 is found during the inspection, the objective lens of the microscope 2 is moved upward as shown in FIG. 1 (B), and the suction nozzle 1 equipped with an air cutoff valve is brought close to the foreign substance 11. Let At this time, the air shutoff valve is closed.

The air shutoff valve is opened to generate an air flow toward the suction nozzle 1 so that the foreign matter 11 is suctioned and removed by the suction nozzle 1 as shown in FIG. 1 (C). Then, the objective lens of the microscope 2 is returned to a predetermined height, it is confirmed that the foreign matter is removed, and the inspection is continued. A brush-shaped wafer protection member may be attached to the tip of the suction nozzle 1 to protect the wafer from damage even if the suction nozzle should contact the wafer.

2 (A), 2 (B) and 2 (C)
Shows a second embodiment of the present invention. This second
In the embodiment, the presence of a foreign substance is automatically detected by a laser oscillator that emits laser light and a laser light receiver. As shown in FIG. 2A, the laser oscillator 4 is installed so that the laser light LB is obliquely incident on the wafer 10 placed on the moving stage 3. If the foreign matter 11 does not exist in the irradiation portion on the wafer 10, the laser light LB is specularly reflected. The laser light receiving device 5 is installed at a position where the regularly reflected laser light LB is not received. The entire surface of the wafer 10 is scanned with this laser light LB. In the figure, the incident laser light is shown by a solid line, and the reflected laser light is shown by a broken line.

As shown in FIG. 2B, the foreign matter 11 is applied to the irradiation part.
Is present, the laser light LB is irregularly reflected, and the laser light LB enters the laser light receiving device 5. The presence of the foreign matter 11 in the irradiation portion can be detected by the laser light receiving device 5 receiving the light. When the foreign matter 11 is detected, the detected position is stored in the memory in the foreign matter inspection apparatus, and the scanning with the laser beam LB is continued.

When the entire surface of the wafer 10 is completely scanned, FIG.
As shown in (C), the moving stage 3 is moved so that the foreign matter position stored in the memory faces the suction nozzle 1.
Remove foreign matter by suction. Similarly, after all the foreign substances stored in the memory are removed, the wafer 10 is again irradiated with the laser beam LB.
Irradiate the position where the foreign material was on to confirm that the foreign material was removed.

Further, a plurality of laser light receiving devices are provided,
If the configuration is such that the presence of foreign matter is discriminated by a plurality of simultaneous light receptions, the foreign matter detection accuracy is improved, and the foreign matter on the wafer on which a pattern such as wiring is formed can be automatically detected. That is, the laser light applied to the step of a pattern or the like is not specularly reflected, but is reflected with a strong directivity so that the laser light is not received by a plurality of laser light receiving devices at the same time. It can be determined that there is no foreign matter in the part. On the other hand, since the laser light applied to the foreign matter is diffusely reflected omnidirectionally, the plurality of laser light receiving devices simultaneously receive the laser light, and it can be determined that the foreign matter is present in the laser light irradiation part.

FIG. 3 shows a third embodiment of the present invention. In the third embodiment, the inspection process for finding foreign matter is omitted. With the nozzle attachment 6 attached to the tip of the suction nozzle 1 and the air shutoff valve opened, this nozzle attachment 6 is rotated in the circumferential direction of the wafer 10. At this time, if the foreign matter 11 exists on the wafer 10, the foreign matter 11 is sucked and removed. FIG. 4 shows a sectional view of the nozzle attachment. The nozzle attachment 6 is formed so that its width is larger than the radius of the wafer 10, and the surface facing the wafer 10 is opened. Also,
A nozzle connecting portion 7 is formed on the upper portion of the nozzle attachment 6.

[0016]

According to the foreign substance removing method of the present invention, the suction nozzle connected to the foreign substance attached to the wafer in the process of manufacturing the semiconductor device is connected to the vacuum source via the airtight hose,
Since the foreign matter can be sucked, the foreign matter can be removed without damaging the semiconductor device formed on the wafer. Further, since the removed foreign matter is transported in the airtight hose, it does not contaminate the inside of the clean room, and there is no possibility that the removed foreign matter reattaches to the wafer. Furthermore, since the vacuum tweezers that are normally provided in a clean room can be diverted as a vacuum source and an airtight hose, the foreign matter removing method according to the present invention does not require the provision of a new device. A special effect is obtained.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a second embodiment of the present invention.

FIG. 3 is a diagram illustrating a third embodiment of the present invention.

FIG. 4 is a cross-sectional view of a nozzle attachment.

[Explanation of symbols]

1: Suction nozzle, 2: Microscope, 3: Moving stage, 4:
Laser oscillator device, 5: Laser light receiving device, 6: Nozzle attachment, 7: Nozzle connection part, 10: Wafer, 1
1: Foreign matter, LB: Laser light

Claims (1)

[Claims] 1. A foreign matter removing method for removing foreign matter adhered to a wafer in the process of manufacturing a semiconductor device, wherein a suction nozzle connected to a vacuum source via an airtight hose is brought close to the foreign matter adhered to the wafer. Then, the air shutoff valve provided in the suction nozzle is opened to generate an air flow toward the suction nozzle to suction and remove the foreign matter from the wafer.