JPH07283286A - Ultra high vacuum transferring device - Google Patents

Abstract

PURPOSE:To transport a sample to a processing device in an ultra-high vacuum while shutting off vibration due to other processing devices in a through vacuum process for semiconductor manufacturing. CONSTITUTION:Between processing devices which need operations in an ultra- high vacuum, a device transfers a sample through a sample transferring path that connects processing devices in an ultra-high vacuum and a sample transferring path 11 and a processing room 12 are isolated by a pair of gate valves 13 and are connected and disconnected with a quick coupling 16. This part is equipped with a vacuum pump that can evacuate the part to an ultra-high vacuum. As the sample is transferred without contamination of the surface of it and is insulated from mechanical vibration, the performance of working fine area and evaluation improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device used for transferring a sample in a device such as a semiconductor manufacturing device which requires a consistent operation in a vacuum, and in particular, a fine processing device in an ultrahigh vacuum. The present invention relates to an ultra-high vacuum transfer device suitable for transferring samples.

[0002]

2. Description of the Related Art Semiconductor manufacturing processes such as crystal growth, patterning, etching, doping, re-growth, and electrode formation are continuously carried out in an ultrahigh vacuum, so that the processed surface is not deteriorated. The vacuum integrated process for manufacturing is manufactured. In this vacuum integrated process, an ultra-high vacuum transfer device that transfers a sample to each process device under ultra-high vacuum is indispensable.

In a conventional ultra-high vacuum transfer device, a stainless steel pipe capable of baking (heating degassing treatment) is flanged via a gasket such as copper in order to reach the ultra-high vacuum region. The method of connecting with is adopted. Therefore, the sample transport path and the process device are connected by a rigidly secured transport path. A conventional specific example will be described in detail with reference to FIG. FIG. 3 is a schematic diagram showing the structure of a conventional ultra-high vacuum transfer device. The sample 34 is installed on the sample carrier 37 installed in the transport path 31. The sample carrier 37 can move in the transfer path 31, and can transfer the sample 34 to each process chamber such as an evaluation chamber and a crystal growth chamber. The sample 34 on the sample carrier 37 is transferred from the transfer path 31 to the process chamber 32 by the transfer rod 35 movable by the magnet 36. During transfer, the gate valve 33 is opened and closed to open or shut off the connection between the process chamber and the transfer path.

[0004]

However, in the vacuum integrated process in semiconductor manufacturing, many devices are connected to one sample transfer path, and in the conventional transfer device, the sample transfer path and the process device or other devices are connected. Since and are firmly fixedly connected, there is a problem that mechanical vibrations are easily transmitted to each other between the process devices through the sample transport path. When mechanical vibration generated in other process equipment is transmitted to a processing or evaluation device that uses a particularly fine electron beam, the mechanical vibration is a major factor that determines the resolution of the processing and evaluation, so the resolution is reduced. Adversely affect. Therefore, various measures have been taken such as placing the entire device on a vibration isolation table using an air spring, and connecting the connection part with a bellows. However, the method of mounting the entire vacuum integrated process device on the seismic isolation table has drawbacks such as an increase in cost and the need to make the device itself compact, and sacrificing developability. Further, the method using the bellows connection can reduce the mechanical vibration transmitted from other process devices and the conveyance path, but cannot eliminate it.

The object of the present invention is to solve the above-mentioned problems, to prevent the mechanical vibration generated in each device in the ultra-high vacuum integrated process from being transmitted to the device for performing fine processing or evaluation of the fine region, and to obtain the ultra-high vacuum. An object of the present invention is to provide a transfer device that can transfer a sample below.

[0006]

In order to achieve the above object, the ultrahigh vacuum transfer apparatus according to the first invention of the present invention comprises: a plurality of process apparatuses; and a sample transfer path for connecting the process apparatuses. An ultra-high vacuum transfer device for transferring a sample under ultra-high vacuum, wherein a section between a sample transfer path and a process device is partitioned by two opening / closing valves, and the section after closing the two opening / closing valves. In the above, it is possible to separate from the sample transport path and / or the process device.

A second aspect of the present invention is characterized in that a vacuum exhaust device is provided which can exhaust the interior of the section partitioned by the two opening / closing valves to an ultrahigh vacuum region in a short time. It is an ultra-high vacuum transfer device.

[0008]

According to the present invention, since the transport path partitioned by the two opening / closing valves and the process chamber can be mechanically completely separated from each other, it is possible to use other devices in a fine processing or evaluation device using an electron beam. Since the mechanical vibration from the outside generated in step 2 is not transmitted through the transport path and the resolution of the processing and evaluation is not lowered, the operation in a good state can be performed. Also, since this device has an exhaust system capable of exhausting the inside of this partitioned section at high speed to the ultra-high vacuum region, it is possible to connect the sections again after disconnection for a short time in the ultra-high vacuum. Since the sample can be transferred under ultra-high vacuum, there is no concern about surface contamination of the semiconductor during the manufacturing process.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the overall structure of the sample transporting apparatus of the present invention. As shown in FIG. 1, the transfer path 11 and the process chamber 12 of the sample transfer apparatus of the present invention are partitioned by two gate valves 13, and the sections partitioned by the two gate valves 13 are separated. There is a part that is connected by a possible quick coupling joint 16, and a vacuum exhaust device 17 that can make an ultrahigh vacuum in that section in a short time is installed.

The sample 14 moves back and forth between the sample transfer path 11 and the process chamber 12 by the transfer rod 15.

The vacuum evacuation device 17 is composed of a combination of a large capacity turbo molecular pump (TMP) and an ion pump (IP), and is used to evacuate the atmosphere at high speed.
IP is used to maintain the degree of vacuum in the ultra-high vacuum region by using P
To use. As a result, the ultimate vacuum is 1 × 10 ^-9 Tor
It can be r or less.

The quick coupling joint 16 corresponds to an ultra-high vacuum by an O-ring seal, and a detachable belt attached to the quick coupling joint 16 allows the connecting portion of the joint 16 to be easily disconnected or reconnected. It has a structure.

Next, the step of transporting a sample using the apparatus of the present invention will be described with reference to FIG. 2A is a block diagram of the apparatus of the present invention showing a sample setting step, FIG. 2B showing a sample transporting step, and FIG. 2C showing a separating step.

First, the sample 24 is set on the side of the transport path 21 (FIG. 2A, sample setting). At this time, the two gate valves 23 are both closed. Also, the transport path 2
The intermediate region connecting 1 to the process chamber 22 is connected by a quick coupling joint 25, and is evacuated to an ultra-high vacuum region by a vacuum exhaust device 26 and held therein.

Next, the sample 24 is transferred from the transfer path 21 to the process chamber 22 (sample transfer in FIG. 2B). At this time,
Both gate valves 23 are opened, and the sample 24 is transferred to the process chamber 22 using a transfer rod (not shown).
Transport to. After transferring the sample to the process chamber 22, the transfer rod is pulled back to the transfer path 21 side, and both gate valves 23 are closed. This is the process chamber 2 for sample 24
The transfer process to 2 is completed.

Thereafter, in order to prevent the mechanical vibration generated from other devices from being transmitted, the process chamber side and the conveying path side are separated at the connection portion by the quick coupling joint 25 (FIG. 2 (c) disconnection). ). First, the gate valve (not shown) of the vacuum exhaust device 26 that has exhausted the inside of the intermediate region partitioned by the two gate valves 13 is closed. Then, nitrogen gas is introduced into the intermediate region to leak to the atmospheric pressure. And quick coupling fitting 25
To separate it into the process chamber side and the transport path side. Immediately thereafter, the sealing lid 27 is attached to the separated portion and vacuum exhaust is performed. This degree of vacuum does not have to reach the ultrahigh vacuum region, and the degree of vacuum is evacuated to about 10 ^-7 Torr.
By exhausting in this way, the separated part can be held without exposing it to the atmosphere. As shown in FIG. 2, the quick coupling joint 25 is installed at a position near one of the two gate valves 23, and a vacuum exhaust device is installed between the quick coupling joint 25 and the other gate valve 23. It is preferable.

In this separated state, the sample carried into the process chamber is subjected to fine processing using an electron beam. Since it is separated from the transport path, mechanical vibration is extremely small, and the minimum processing size was about 1 μm when it was connected to another device by the transport path. Processing of 50 nm, which is about the same size as the diameter, has become possible. Also, in the evaluation of the fine area in the scanning electron microscope mode using secondary electrons, the resolution was about 1 μm in the past, but it was about several tens of nm when separated, and the performance was comparable to that of fine processing. Improved.

Although the steps up to the separation have been described above in detail, the method of connecting the process device side and the transport path side again after the process is completed is the reverse of the work up to now. First, both sides closed by the sealing lid 27 are leaked to atmospheric pressure with nitrogen gas, and quickly connected by the quick coupling joint 25. Then, the vacuum exhaust device 26 is used to exhaust to an ultrahigh vacuum region. After exhausting sufficiently to the 10 ^-8 Torr level, both gate valves 23 are opened and the sample 24 in the process chamber 22 is transferred by the transfer rod to the transfer path 2
Transport to 1 side. After the transportation is completed, both gate valves 23 are closed. By the above operation, the sample in the process chamber 22 can be moved to the transport path side.

In the transfer method using the apparatus of the present invention, the transfer path is exposed to the atmosphere once, but in a very short time, and the sample is transferred immediately after it is evacuated to a high vacuum region. The effect of air pollution on the surface is considered to be extremely small. When the surface of the sample transported in this way was actually examined by Auger electron spectroscopy, no signals from elements such as oxygen and carbon, which are considered to be the cause of atmospheric pollution, were observed, and a very clean surface was maintained. I found out.

Further, it is considered that it takes time to transfer the sample because the transfer path is exposed to the atmosphere once and then vacuum exhaust is performed, but this problem can be avoided by installing a large capacity TMP. Also, taking the etching process using chlorine gas during semiconductor manufacturing as an example, the time to evacuate the process chamber to high vacuum after the process is almost the same as the time to evacuate the transfer path to high vacuum. It was found that the time of applying the vacuum did not adversely affect the throughput.

[0022]

As described above, by using the ultra-high vacuum sample transfer device of the present invention, mechanical vibrations from other devices such as other devices can be avoided in microfabrication using an electron beam or in the evaluation of a minute area. Since it is not affected, it is possible to process and evaluate a fine region with high resolution, and since the sample is transported under ultra-high vacuum, there is no concern about contamination of the sample surface by the atmosphere.

Further, according to the present invention, unlike the conventional apparatus for mounting the entire apparatus on the seismic isolation table, it is not necessary to make the entire apparatus used for the vacuum integrated process compact, and it is necessary to add a new process apparatus. Since it suffices to attach the transport device of the invention, the developability is not sacrificed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the overall configuration of a sample transport device of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of an apparatus in each step of sample transport using the sample transport apparatus of the present invention. (A) The block diagram of this invention in a sample installation process. (B) The block diagram of this invention in a sample conveyance process. (C) The block diagram of this invention in a cutting process.

FIG. 3 is a configuration diagram showing an entire conventional sample transport device.

[Explanation of symbols]

 11, 21, 31 Conveying path 12, 22, 32 Process chamber 13, 23, 33 Gate valve 14, 24, 34 Sample 15, 35 Transfer rod 16, 25 Quick coupling joint 17, 26 Vacuum exhaust device 27 Sealing lid 36 Magnet 37 sample carrier

Claims (2)

[Claims] 1. An ultra-high vacuum transfer apparatus for transferring a sample between a plurality of process apparatuses under an ultra-high vacuum by a sample transfer path connecting the process apparatuses, the sample transfer path and the process apparatus. Is divided by two opening / closing valves, and in the section after closing the two opening / closing valves, the sample transfer path and / or the process device can be separated from either or either one of the above. High vacuum transfer device. 2. The ultra-high vacuum transfer apparatus according to claim 1, further comprising a vacuum exhaust device capable of exhausting the interior of the section partitioned by the two opening / closing valves to an ultra-high vacuum region.