JPH0575955U - Vacuum processing device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a vacuum processing apparatus capable of monitoring particles in an airlock system on the spot. A flow cell type particle measuring instrument 30 or 32 having a flow cell in both the vent line 12 and the evacuation line 20 of the airlock chamber 6 for measuring the number of particles contained in the gas passing therethrough. Are provided respectively.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention is for treating a workpiece in a vacuum, such as an ion implantation apparatus, an etching apparatus, and a thin film forming apparatus, and for moving the workpiece in and out of the processing chamber. The present invention relates to a vacuum processing apparatus including an airlock chamber, and more specifically to a means for monitoring particles in the airlock system on the spot.

[0002]

[Prior Art]

 FIG. 3 shows a conventional example of this type of vacuum processing apparatus. This apparatus is a processing chamber 4 for processing an object to be processed (for example, a wafer, various substrates, etc.) 2 (for example, performing ion implantation, etching, etc.), and is adjacent to the processing chamber 4 4 and the atmosphere, an air lock chamber 6 for putting in and out, a first vacuum valve (for example, a gate valve) 8 for partitioning the air lock chamber 6 and the processing chamber 4, and the air lock chamber 6 A second vacuum valve (for example, a gate valve) 10 for partitioning into the atmosphere, a vacuum drawing line 20 for emptying the air lock chamber 6 and a gas (for example, nitrogen gas) 18 are injected into the air lock chamber 6. And a vent line 12 for venting.

The evacuation line 20 is connected to a vacuum pump (not shown) via a vacuum valve 22. A vent valve 14 and a filter 16 are provided in the vent line 12. The filter 16 removes particles in the gas 18 that vents the airlock chamber 6 to prevent contamination of the object 2 to be processed, and may be provided downstream of the vent valve 14.

When the object 2 to be processed is transferred from the atmosphere into the processing chamber 4 for processing, first, the vacuum valve 10 on the atmosphere side is opened, and the object 2 is transferred into the airlock chamber 6 which has been set to atmospheric pressure in advance. The air lock chamber 6 is evacuated by a vacuum pump (not shown) to reach a predetermined vacuum degree (for example, about 10 ^-2 to 10 ^-3 Torr). Then, the vacuum valve 8 on the side of the processing chamber 4 is opened and the object 2 to be processed is transported to the processing place in the processing chamber 4. It is assumed that the inside of the processing chamber 4 is evacuated to a predetermined vacuum degree (for example, about 10 ⁻⁵ to 10 ⁻⁶ Torr) necessary for processing the object 2 to be processed. The above-described conveyance of the object to be processed 2 is performed by a conveyance means such as a conveyance belt and a conveyance arm (not shown).

When the processed object 2 in the processing chamber 4 is transferred to the atmosphere, the vacuum valve 8 is opened to transfer the object 2 into the airlock chamber 6, and the vacuum valve 8 is closed. The vent valve 14 is opened to inject a gas 18 from a gas source (not shown) into the airlock chamber 6 to make it atmospheric pressure, and then the vacuum valve 10 is opened to convey the object 2 to the atmosphere.

[0006]

[Problems to be solved by the device]

 In the vacuum processing apparatus described above, the vent line 12 is provided with the filter 16 to remove particles in the gas 18 that vents the air lock chamber 6. However, focusing on the point that the object 2 is contaminated by particles, the generation of particles from the moving parts such as the valves 8, 10, 14 and 22 and the vacuum valve 10 due to the differential pressure between the air lock chamber 6 and the atmosphere. There are many problems such as particle entrapment during opening and closing, overflow of the filter 16 and inflow of particles from the vent line 12 due to aging.

In order to check the degree of contamination by particles in the airlock system including the airlock chamber 6 and the devices such as valves and filters incidental to the airlock chamber 6, conventionally, a clean object 2 to be processed is placed in the airlock chamber 6. The particles were transported through the substrate, and the change in the number of particles adhering to the workpiece 2 before and after the transportation was measured by a laser particle counter or the like.

However, such a method is very time-consuming and has a problem that a sudden abnormality cannot be immediately monitored.

Therefore, the main object of the present invention is to provide a vacuum processing apparatus capable of in-situ monitoring the particles in the air lock system as described above.

[0010]

[Means for Solving the Problems]

 In order to achieve the above object, the vacuum processing apparatus of the present invention has a flow cell in at least one of the vent line and the evacuation line of the air chamber as described above, and is included in the gas passing therethrough. It is characterized by the provision of a flow cell type particle counter that measures the number of existing particles.

[0011]

[Action]

 By installing a flow cell type particle measuring instrument at the above location, the number of particles contained in the gas injected when venting the airlock chamber and the gas exhausted when evacuating the airlock chamber are included. At least one of the number of existing particles can be measured. Moreover, this measurement can always be performed under the normal use condition of the vacuum processing apparatus. Therefore, by providing such a flow cell type particle measuring instrument, it is possible to monitor the particles in the airlock system on the spot.

[0012]

【Example】

 FIG. 1 is a schematic sectional view partially showing a vacuum processing apparatus according to an embodiment of the present invention. The same or corresponding portions as those of the conventional example in FIG. 3 are denoted by the same reference numerals, and the differences from the conventional example will be mainly described below.

In this embodiment, flow cell type particle measuring instruments 30 and 32 are provided on both the vent line 12 and the evacuation line 20 of the airlock chamber 6 as described above, respectively.

Both the flow cell type particle measuring instruments 30 and 32 have a flow cell and measure the number of particles contained in the gas passing through the flow cell. For example, a leak tight manufactured by Lion Corporation is used. This is a particle-type particle measuring instrument KC-90, and has a configuration as shown in FIG.

That is, each of the flow cell type particle measuring instruments 30 and 32 has a flow cell 42 through which a gas to be measured is flown. In the case of the flow cell type particle measuring device 30, the gas in the vent line 12 is contained in the flow cell 42. In the case of the flow cell type particle measuring instrument 32, the gas in the evacuation line 20 respectively flows. Then, the laser beam 36 generated by the semiconductor laser 34 is collimated by the collimator 38 (that is, made into a thick parallel beam) and is incident on the elliptical mirror 40 from the non-focus direction. As a result, the laser beam 36 reflected by the elliptical mirror 40 has a flat shape perpendicular to the gas flow direction at the intersection with the flow cell 42, which is the measurement region.

The scattered light 37 due to the particles in the gas in the measurement region is condensed by the collector lens 44 having a depth of focus sufficiently deeper than the width of the gas flow path, and the scattered light of the flow cell 42 itself by the double slit 46. After being separated, it is guided to the photodiode 48 where it is converted into an electric signal. Then, the electric signal from the photodiode 48 is measured by the measuring circuit 50.

The features of such flow cell type particle measuring instruments 30 and 32 are as follows.

A pulse signal is output from the photodiode 48 according to the number of particles contained in the gas passing through the flow cell 42. Therefore, by counting the number by the measuring circuit 50, the gas passing through the flow cell 42 is counted. You can count the number of particles contained in it.

Since the intensity of the scattered light 37 monotonically increases according to the size of the particles, it is possible to measure the particle size accurately by measuring the size of the signal output from the photodiode 48.

The particles in the gas passing through the flow cell 42 can be measured in their entirety, rather than as sampled. That is, instead of estimating the whole from the sample value, it is possible to actually measure the whole actual measured gas.

In the flow cell 42, particles can be measured under pressure or under reduced pressure.

However, at present, measurement in a high vacuum region is impossible.

Therefore, in the flow cell type particle measuring instrument 30 provided in the vent line 12, when the air lock chamber 6 is vented, the flow cell 42 is in a low vacuum to a pressurized region (a low vacuum region at the beginning of the vent and an end at the end. It can be measured because it is in a slightly pressurized area (atmospheric pressure), and it is possible to monitor the scattered light output, for example, the life of the filter 16 and the number of particles flowing into the airlock chamber 6 due to the vent valve 14 or the like. it can.

Further, in the flow cell type particle measuring instrument 32 provided in the evacuation line 20, when the air lock chamber 6 is evacuated, the flow cell 42 is used to exhaust the particles in the air lock chamber 6 together with the air. Can be measured because it is in the atmospheric pressure to low vacuum region (atmospheric pressure region at the beginning of vacuum evacuation and low vacuum region at the end), and the particles generated in the airlock chamber 6 can be monitored from the scattered light output. You can

Moreover, the above-described measurement can be always performed under the normal use condition of the vacuum processing apparatus. Therefore, by providing the flow cell type particle measuring instruments 30 and 32 as described above, the particles in the airlock system can be monitored on the spot. As a result, the status of each device in the airlock system, especially the soundness of the filter 16 can be monitored on the spot without time delay, and it is possible to immediately detect a sudden abnormality. Become.

It should be noted that the flow cell type particle measuring device can provide more accurate measurement if it is provided on both the vent line 12 and the vacuuming line 20 for the airlock chamber 6 as in the above embodiment. Even if only one of the vent line 12 and the evacuation line 20 is provided, the above-described purpose of monitoring particles in the airlock system on the spot can be sufficiently achieved.

[0027]

[Effect of the device]

 As described above, according to the present invention, since the flow cell type particle measuring instrument as described above is provided, the particles in the airlock system can be monitored on the spot. As a result, since it is possible to monitor the soundness of each device in the airlock system in a place where there is a time delay, it is also possible to immediately detect a sudden abnormality.

[Brief description of drawings]

FIG. 1 is a schematic sectional view partially showing a vacuum processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a flow cell type particle measuring instrument in FIG.

FIG. 3 is a schematic sectional view partially showing an example of a conventional vacuum processing apparatus.

[Explanation of symbols]

 2 Processing object 4 Processing chamber 6 Airlock chamber 8,10 Vacuum valve 12 Vent line 20 Vacuuming line 30,32 Flow cell type particle measuring instrument

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H01L 21/68 A 8418-4M

Claims (1)

[Scope of utility model registration request] 1. A processing chamber for processing an object to be processed, an airlock chamber which is adjacent to the processing chamber and which is used to take in and out the object to be processed between the processing chamber and the atmosphere, and the airlock chamber. A first vacuum valve for partitioning the processing chamber, a second vacuum valve for partitioning the airlock chamber from the atmosphere, a vacuum line for vacuuming the airlock chamber, and a gas in the airlock chamber. In a vacuum processing apparatus having a vent line for injecting and venting, at least one of a vent line and a vacuuming line of the airlock chamber has a flow cell and has a particle content of a gas passing therethrough. A vacuum processing apparatus, which is provided with a flow cell type particle measuring device for measuring the number.