JPH0551749A - Vacuum treating device - Google Patents

Abstract

PURPOSE:To prevent the deposition of particles on a material to be treated by injecting UV into a gas passing through a tube with the inner surface formed with an insulator and introducing the gas into a vessel. CONSTITUTION:A sample 107 is treated in the load-lock chamber 101 of a vacuum vessel. Nitrogen gas passing through a pipeline 103 is irradiated with UV from a deuterium lamp 104. The partially ionized nitrogen gas flows onto the sample 107 to remove electrification of the sample. The pipeline 103 is formed with an insulator to prevent the neutralization of the formed ion and electron. Even if the sample 107 moving in the vessel is charged, the electric charge is neutralized. Consequently, the particles are not deposited on the sample 107, and yields are increased.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum processing apparatus formed by connecting a plurality of vacuum vessels, and more particularly to a vacuum processing apparatus for preventing particles from adhering to an object to be processed in a vacuum vessel such as a load lock chamber. It is a thing.

[0002]

2. Description of the Related Art FIG. 4 shows the structure of a general vacuum transfer processing apparatus.

In the figure, 401 is a load lock chamber, 402 is a transfer chamber, and 403 is a reaction chamber.
The chambers are connected in a chain. When actually performing the process, first, the wafer is put in a holder such as a cassette, and then the door 404 is opened and set under the atmospheric pressure, and the door is closed. Then, the vacuum pump 405 is used to load the load lock chamber 4
01 is evacuated to about 10 ^-6 Torr. At this time, the transfer chamber 402 is evacuated by the vacuum pump 406 to a vacuum degree of about 10 ⁻⁸ Torr, the gate valve 407 between the load lock chamber 401 and the transfer chamber 402 is opened to transfer the wafer, and then the wafer is transferred. -Close valve 407. At this time, 10 ^{-1 0} Tor reaction chamber 403 by the vacuum pump 408
The transfer chamber 402 and the reaction chamber 4 are evacuated to a vacuum degree of about r.
The gate valve 409 located between 03 and 03 is opened to transfer the wafer. This will reduce the vacuum to atmospheric pressure.
The docking chamber 401 and the reaction chamber 403 can be transported without directly touching the same atmosphere, and the reaction chamber 403 can always be kept in a high vacuum state. When the wafer is transferred to the reaction chamber 403, the gate valve 409 is closed to close the reaction chamber 403, and the vacuum pump further draws a high vacuum. In this state, for example, a predetermined gas is introduced into the reaction chamber 403 via the gas pipe 410 to perform the process. After the process is completed, the gate valve 409 is opened again and the wafer transfer chamber 4 is opened.
02. Then, the gate valve 409 is closed to shut off the reaction chamber 403, and then the gate valve 407 is opened to convey the load lock chamber 401. After the transfer, the gate valve 407 is closed and the transfer chamber 402 and the load lock chamber 401 are shut off. After that, gas is flown through the gas introduction port 411 to leak the load lock chamber 401, the vacuum degree is lowered to the atmospheric pressure, and the wafer is taken out under the atmospheric pressure. As described above, when the wafer is taken out from the load lock chamber, a dry gas such as nitrogen gas or argon gas is caused to flow into the chamber to leak the chamber.

[0004]

The above-mentioned prior art has a big problem in the leak of the load lock chamber. That is, for example, when flowing dry nitrogen gas from the gas inlet,
The particles in the load lock chamber may rise and fall on the wafer, or the wafer may be charged due to static electricity generated by flowing the nitrogen gas and a large amount of particles may adhere to the wafer. For this reason, in the conventional load lock chamber, the adhered particles contaminate the wafer and reduce the yield. Note that, for example, in order to solve the above-mentioned problem of charging, measures such as reducing the flow rate of nitrogen gas used for leaking the chamber have been taken, but for the adhesion of particles, the factor due to the charging of the wafer is too large and a sufficient effect can be obtained. Absent.

[0005]

A vacuum processing apparatus according to the present invention comprises a plurality of containers, each of which is capable of depressurizing, connected in series through an opening / closing mechanism, and an object to be processed can be moved between the containers. In the vacuum device described above, a light projecting unit for projecting ultraviolet light to at least one gas body introduced into the container is provided. Since the gas body is ionized by the light projecting means to irradiate the sample, the charge of the sample can be removed.

[0006]

The gas (for example, nitrogen gas) introduced into the container (for example, the load lock chamber) is ionized by the ultraviolet rays projected from the light projecting means (for example, the deuterium lamp), so that the object to be placed in the container is kept. Even when the processed object (for example, wafer) is charged, the charged electric charge is neutralized by the ionized charged body.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, only a typical load lock chamber among the vacuum containers that are installed in a stack will be described.
FIG. 1 shows a first embodiment. 1 in FIG.
Reference numeral 1 denotes a load lock chamber which is a vacuum container. For example, the material is SUS316L, the inner surface of which is subjected to complex electropolishing and oxidation passivation treatment, and is formed into a hollow cubic box shape with one side of 300 mm.

Reference numeral 102 denotes a gas pipe, which is made of, for example, SUS316L, the inner surface of which is subjected to complex electrolytic polishing and oxidation passivation treatment, and has a diameter of 1/4 inch. Argon is used as the gas.

Reference numeral 103 is a gas pipe, for example, made of SUS316L, the inner surface of which is subjected to complex electrolytic polishing and oxidation passivation treatment, and has a diameter of 1/4 inch. As this gas, for example, nitrogen gas is used.

Reference numeral 104 denotes an ultraviolet light projecting section, which is composed of, for example, a deuterium lamp.

Reference numeral 105 denotes a window through which ultraviolet light is projected when it is projected onto the gas, and synthetic quartz which allows ultraviolet light having a wavelength of 360 nm or less to pass therethrough is used. Other materials may be used as long as they transmit ultraviolet light.

Reference numeral 106 is a sample susceptor, for example, made of SUS316L, the surface of which is subjected to complex electropolishing, and its size is 6 inches in diameter.

Reference numeral 107 is a sample, for example, a silicon wafer having a diameter of 5 inches was used.

Reference numeral 108 denotes a vacuum pump for evacuating the vacuum tank, and for example, a turbo molecular pump is used.

The actual operation principle will be described below.

When the nitrogen gas flows through the pipe 103, the ultraviolet light emitted from the deuterium lamp 104 is applied to the nitrogen gas through the synthetic quartz window 105. A part of the nitrogen gas is ionized into N ₂ ⁺ and e ⁻ by the irradiated ultraviolet rays and flows into the silicon wafer in an ionized state to remove the charge on the wafer. For example, the turbo molecular pump 108 is stopped without flowing the nitrogen gas projected by the ultraviolet rays, and only the argon gas is allowed to flow through the pipe 102, for example, at a rate of 2 to 3 l / min to leak the load lock chamber and to remove particles on the silicon wafer at that time. 10 when measured with a particle measuring device
The number was from 00 to 1500. Under the same conditions as above, when nitrogen gas was flowed through the pipe 103 at a normal pressure of 5 cc / min to project the deuterium lamp 104, the number of particles on the silicon wafer was 5 or less as measured by a usual method. Thus, there is a remarkable effect that the number of particles can be drastically reduced.

In the above embodiment, the vacuum tank 101 and the pipe 102 are made of, for example, SUS316L, the inner surface of which is subjected to complex electrolytic polishing and oxidation passivation treatment. You may use the thing.

In the above embodiment, the pipe 103 is made of, for example, SUS316L whose inner surface is subjected to complex electrolytic polishing and oxidation passivation treatment. However, for example, a tube having Teflon coated on its inner surface or a ceramic tube may be used. Good. The point is that the surface should be an insulator so as not to neutralize the formed ions and electrons.

In the above-described embodiment, the susceptor 106 is made of SUS316L and is subjected to composite electrolytic polishing. However, the susceptor 106 may be made of any material or shape depending on the application.

Although a silicon wafer is used as the sample 107 in the above embodiment, any material may be used depending on the application. That is, it may be a quartz substrate, a glass substrate, or a compound semiconductor wafer such as gallium arsenide.

In the above embodiment, for example, a turbo molecular pump was used as the vacuum pump 108, but any vacuum pump may be used depending on the application.

Further, in the above embodiment, nitrogen gas was used as the first gas and argon gas was used as the second gas, but any gas may be used as long as it is a dry gas, and the gas inlet port 10 may be used.
The gases introduced into 2 and 103 may be the same. Desirably, the oxygen concentration is 10 ppm or less. This is because ozone is generated and N ₂ ⁺ ions are reduced by the ultraviolet irradiation. The gas inlets are also individual in the above embodiment, but they may be common.

FIG. 2 shows a second embodiment.

In this embodiment, the pipe 103 of the above-mentioned embodiment is constituted by a pipe 201 which is extended to a position closest to the sample 107. Since other constitutions are the same as those of the first embodiment, duplicated explanation will be omitted. As in the case of the first embodiment, the nitrogen gas onto which the ultraviolet light was projected was made to flow through the pipe 103, and the number of particles measured by the particle measuring device was 5 or less. That is, it has the same effect as that of the first embodiment.

In the above embodiment, for example, the gas pipe 2
Although 01 was extended to the vicinity of the sample, this pipe 201 may be anywhere as long as gas can be introduced into the vacuum tank and may be movable.

Further, in the above embodiment, for example, the pipe 201 is a straight pipe, but it may be a curved pipe according to its application.

FIG. 3 shows a third embodiment.

In this embodiment, the susceptor 106 of the embodiment is used.
Carrier 3 capable of processing a plurality of wafers 302, for example
The configuration is 01. Other configurations are first
The same as in the example. As a result of flowing a nitrogen gas in the same manner as in the first embodiment, the particles were measured by a particle measuring device. As a result, when a carrier capable of holding, for example, 5 wafers was used, the average number of particles was 5 or less per wafer. .. The same effect as the first embodiment is obtained.

The carrier 301 of the third embodiment has a structure in which, for example, five wafers are held vertically, but may be held at an arbitrary angle depending on the application.

In the above-mentioned first to third embodiments, the nitrogen gas irradiated with ultraviolet light is introduced into the load lock chamber in order to prevent the wafer from being charged when the chamber leaks. However, it has been reported that the wafer is electrically charged even during the transportation of the wafer in vacuum. The cause has not been clarified so far, but since the electrostatic charge on the wafer can be removed by introducing the above-mentioned ultraviolet-ray-transmitted gas into the transfer chamber, the inlet of the transfer chamber must be installed to prevent electrostatic charge during transfer. May be provided.

[0031]

According to the first aspect of the present invention, even when the object to be processed moving between the containers is charged, the electrostatic charge is neutralized, and the particles can be prevented from adhering to the object to be processed.
This can contribute to avoiding a decrease in the yield of objects to be processed.

According to the second aspect of the present invention, the ionized gas body can be efficiently supplied to the sample as the sample.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of a vacuum processing apparatus according to a first embodiment.

FIG. 2 is a schematic view of a main part of a vacuum processing apparatus according to a second embodiment.

FIG. 3 is a schematic view of a main part of a vacuum processing apparatus according to a third embodiment.

FIG. 4 is a schematic diagram of a vacuum processing apparatus according to a conventional technique.

[Explanation of symbols]

 101 vacuum tank container, 102 second gas pipe, 103 first gas pipe, 104 UV light projecting means, 105 synthetic quartz window light projecting part, 106 susceptor, 107 sample (processed object), 108 vacuum pump, 201 gas pipe, 301 susceptor, 302 sample (processing object).

Claims (4)

[Claims] 1. A vacuum device comprising a plurality of containers, each of which is capable of depressurizing, connected in series via an opening / closing mechanism, and is capable of moving an object to be processed between the respective containers. A vacuum processing apparatus, characterized in that a light projecting means for projecting ultraviolet light is provided on the gas body introduced into the vacuum processing apparatus. 2. The light projecting means is provided between the at least one container and the gas body supply means, and irradiates a gas body introduced into a tube body at least an inner surface of which is made of an insulator. The vacuum processing apparatus according to claim 1, wherein: 3. The vacuum processing apparatus according to claim 1, wherein the gas body is nitrogen gas or argon gas, or a mixed gas of nitrogen gas and argon gas. 4. The vacuum processing according to claim 1, wherein the light projecting means irradiates the gas body through a light projecting portion made of synthetic quartz. apparatus.