JPH02308528A - Low temperature treatment device - Google Patents

Abstract

PURPOSE:To solve the problem of dewing accompanying the sharp temperature rise of material to be treated by forming a carrying-in part for material to be treated and plural cooling chambers where the temperature is lowered gradually toward a low temperature processing chamber. CONSTITUTION:This is arranged in such constitution that cooling chambers 41-43 are arranged continuously in multistage in the order of temperature in a low temperature treatment device, that wafer susceptors 61-63 to support materials 1 to be treated are provided in every cooling chamber 41-43, and that they are connected to a temperature processing chamber 2 so that the temperatures of wafer susceptors may be lower by stages from the loading side of the processing material 1. While, the unloading side is in reverse constitution, where the processing material 1 is heat-treated by stages from the low temperature processing chamber 2 to a taking-out part 5 so as to prevent dewing of the processing material 1. The processing material 1 is exposed to the air the taking-out part 5 after being heated, whereby the dewing of the processing material 1, which was defects in low temperature process, is prevented, and phased cooling is made effective, and superfluous processes such as heating, passivation, etc., are made needless.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a low-temperature processing apparatus, and particularly to a low-temperature processing apparatus in which a material to be treated is carried into a low-temperature treatment chamber, and the material to be treated is subjected to low-temperature treatment in the low-temperature treatment chamber. INDUSTRIAL APPLICABILITY The present invention, which relates to a processing apparatus, can be used, for example, in the field of electronic material formation, as a low-temperature processing apparatus that performs low-temperature etching or low-temperature CVD on semiconductor wafers.

[Summary of the invention]

The low-temperature processing apparatus of the present invention has a plurality of cooling chambers in which the temperature is sequentially lowered toward the low-temperature processing chamber between the loading part of the material to be processed and the low-temperature processing chamber, so that the material to be processed after low-temperature processing is The materials can be taken out through heating chambers corresponding to the plurality of cooling chambers mentioned above, and are gradually heated and taken out without being suddenly exposed to atmospheric temperature from a low temperature state, which is different from the conventional method of transporting processed materials. It can solve problems such as dew condensation.

[Conventional technology]

In recent years, low-temperature processing technology, that is, technology that performs processing at low temperatures, particularly at temperatures below 0° C., has attracted attention.

For example, low-etching technology is attracting attention as a technology that can achieve both anisotropy, which was said to be contradictory with conventional RIE technology, and low-damage, high-speed etching (for example, the Institute of Electrical Engineers of Japan, Society sample ED low 88-
421”Low-Temperature Reac-
tive Ion Etching and Mic
(see rowave Plasma Etching).

[Problem that the invention seeks to solve]

However, with the above-mentioned low-temperature processing technology, there are still problems to be solved.

One of the problems is how to cool the material to be processed when it is transported into a processing chamber where the material is subjected to low-temperature processing.

Another problem is how to take out the treated material into the atmosphere after treatment.

In other words, in conventional low-temperature processing techniques, such as those using conventional low-temperature etching equipment, etching is performed by cooling the processing material, such as a wafer, to below 0°C. There was a drawback that dew condensation formed on the wafer when it was taken out.

This is a major problem that can significantly reduce process reliability and offset the inherent effectiveness of low temperature etching.

For this reason, for example, as seen in Japanese Patent Application Laid-Open No. 63-60529, a technique has been proposed in which a heating chamber is provided between the processing chamber and the wafer cassette chamber, and a chamber is provided for the purpose of raising the temperature of the wafer. However,
If an attempt is made to irradiate the wafer with a lamp to the extent that it heats the back surface of the wafer in this way, there is a drawback that the balance between the processing time and the heating time becomes poor. That is, for example, it is necessary to remove heat using a lamp, but it is not always easy to perform this in a well-controlled and well-balanced manner.

On the other hand, as mentioned above, how to cool the wafer, which is the material to be processed, is also an important issue. The material to be processed is required to be cooled efficiently, quickly, and uniformly.

Currently known devices suppress the temperature rise of the wafer by flowing water over the wafer-mounted electrode, but one example is to flow liquid nitrogen instead of this cooling water to achieve rapid cooling. It is possible to achieve this. However, when trying to apply this idea, it is impossible to realize this idea using conventional equipment as is, considering the material of the piping, prevention of dew condensation, etc., and using liquid nitrogen is not practical. Not only is it difficult, it requires constant replenishment, and manufacturing costs are high.

Therefore, it is most practical to employ a technique that cools the wafer, which is the material to be processed, by circulating the coolant. At this time, it is impossible to cool the temperature from room temperature to below i00°C all at once, and it is necessary to cool it in several stages.

In this way, with the current technology, it is inevitable to take steps to cool the material to be treated in stages.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, it is an object of the present invention to provide a low-temperature processing apparatus that prevents inconveniences such as dew condensation from occurring when a material to be processed is taken out.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a low-temperature processing apparatus that transports a material to be processed into a low-temperature processing chamber and performs low-temperature processing on the material to be processed in the low-temperature processing chamber. A plurality of cooling chambers whose temperature is successively lowered toward the low-temperature processing chamber are formed between the two.

C Effect] According to the present invention, when the material to be processed is transported from the loading section to the low-temperature processing chamber, it passes through a plurality of cooling chambers whose temperature is successively lowered, so that it is slowly cooled before being transported. , the conventional multi-stage cooling system can be used as is. On the other hand, after low-temperature processing, the material to be processed is heated in stages from the low-temperature processing chamber to increase its temperature, with the configuration reversed to the above, and this heat removal prevents dew condensation on the material to be processed. .

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. This embodiment embodies the present invention as a low-temperature etching apparatus used in a semiconductor AM process.

As shown in FIG. 1, in the apparatus according to this embodiment, a material to be processed 1 (here, a wafer) is carried into a low-temperature processing chamber 2 (here, a process chamber for performing low-temperature etching). A low-temperature processing apparatus that performs low-temperature processing on a material to be processed, which includes a plurality of cooling chambers 41 between the loading section 3 for the material to be processed and the low-temperature processing chamber 2, the temperature of which is sequentially lowered toward the low-temperature processing chamber 2. ~43 was formed.

According to this configuration, when the wafer, which is the material to be processed 1, is carried in from the carrying-in section 3, it sequentially passes through a plurality of cooling chambers 41 to 43, so that a large number of stepwise cooling steps that have been conventionally adopted without problems are performed. The process can be used as is. and,
When taking out the processed material 1 after processing, each cooling chamber 41 to
The material to be treated I can be taken out through heating chambers 41' to 43' corresponding to the cooling chambers 43, that is, the temperature of which is controlled in the same manner as in each cooling chamber. As a result, the temperature of the treated material 1 rises while removing heat, so it is possible to solve the problem of dew condensation caused by rapid heating (rapid rise to atmospheric temperature i!L), which was a drawback of the conventional method. can.

The present example will be described in more detail as follows.

As mentioned above, if the conventional one-shot cooling process is adopted, the cooling system must be installed in multiple stages, but in this example, it is installed in multiple stages, and each cooling chamber 41 to 43 is Arranged consecutively. Each cooling room 4
Wafer susceptors 61 to 63 for supporting wafers, which are the material to be processed 1, were provided in each chamber. In this way, the temperature of the wafer susceptor is gradually lowered from the load side (carrying section 3 side) of the wafer, which is the material to be processed, and thereby the temperature of the cooling chambers 41 to 43 is sequentially lowered. I made it. Each cooling room 41-43
can be configured as they are or as corresponding heating chambers 41' to 43' using the same temperature control means. Each heating chamber 4
1' to 43' are also provided with supporting susceptors 61' for each chamber.
-63' are provided to control the temperature of the material I to be treated at the temperature of the susceptor.
-13' schematically shows the case where the treated material 1 is placed in each chamber 41-43, and 41'-43'.

Note that the heating chamber is a portion in which the temperature of the material to be treated 1 is raised to atmospheric temperature, but is referred to herein as a heating chamber in correspondence with the cooling chamber.

With the above configuration, the material to be processed 1 is transported from the loading section 3.
When a wafer is carried in, the material to be processed l is gradually cooled. Further, in this case, the total throughput can be improved by providing a transport system in which each wafer susceptor is always loaded with one processed material 1 (wafer).

On the other hand, when the processing process in the low-temperature processing chamber 1 is completed and the material to be processed 1 is taken out to the take-out section 5 (unloading chamber), the situation is reversed. That is, the material to be processed 1 first passes through a heating chamber 43' whose temperature is closest to the low-temperature processing chamber 2, then passes through a heating chamber 42' and a heating chamber 43' whose temperature sequentially increases, and reaches the take-out section 5. Therefore, the material to be treated 1 is gradually heated to room temperature, and no dew condensation occurs after it is taken out into the atmosphere.

At this time, by using the same transport system as that on the import side, the total throughput can be improved.

In this embodiment, the cooling system uses fluorocarbons R-22, R-13, and R-14 as refrigerants, and performs heat exchange using a so-called Carno cycle.

That is, in the cooling chamber 41 and the heating chamber 41', the refrigerant is compressed by the compressor 71 for fluorocarbon gas R-22, passed through the condenser 10, and heat exchanged by the heat exchanger 81, so that the refrigerant is transferred to each support (susceptor) 61. 61' to a predetermined temperature, and the evaporator 91 (-15
℃) to the compressor 7I, thereby bringing the material 1 to be treated to about -15°C. Similarly, the cooling chamber 42,
In the heating chamber 42', similarly, the compressor 72 for fluorocarbon gas R-13, the heat exchanger 82, and the evaporator 92 (-75°C) are used to bring the material to be treated 1 to about -75°C.

In the cooling chamber 43 and heating chamber 43', a compressor 73 for fluorocarbon gas R-14, a heat exchanger 83, and an evaporator 93 (
-120°C) to bring the material to be treated l to about -120°C.

The processing temperature of the low temperature processing chamber 1 is 1. The temperature was set at about -120°C. Arrows in the figure indicate the flow of refrigerant.

Also, although omitted in the figure, the cooling side (cooling chambers 41 to 43)
The refrigerant was also passed through the same system. That is, it is possible to install another identical system or to share a cooling system. .

In this embodiment, a wafer cassette 31 is arranged in a loading chamber constituting the loading section 3, and the material to be processed 1 (wafer) is stored therein. Removal part 5
There is also a wafer cassette 51 in the unload chamber forming the wafer cassette, into which the material to be processed 1 is returned. Each cassette) 3L
The material to be treated in 51 is schematically indicated by reference numeral 14.14'.

The loading section 3, each of the cooling chambers 41 to 43, and the low temperature processing chamber 2 are continuously connected via gate valves 101 to 104. The take-out section 5, each heating chamber 41' to 43', and the low-temperature treatment chamber 2 also contain gate pulp 101' to 104'.
are connected continuously through. This makes it possible to realize a series of processing processes through continuous conveyance and unloading.

Each chamber, that is, the low-temperature processing chamber 2, the heating chambers 41 to 43, and the cooling chambers 41' to 43' can be installed in the same chamber via a thermal insulator.

In the basic configuration of this embodiment, each room is provided in stages, so
Although the total throughput is improved, this effect can be further enhanced by doing as described above.

In this embodiment, as described above, the cooling chambers 41 to 43 are arranged in succession in order of temperature and provided in multiple stages, and the cooling chambers 41 to 43 are
A wafer susceptor 61 that supports the processed material 1 every 3
~ 63 are provided, and the temperature of the wafer susceptor is gradually lowered from the load side of the processed material l to the low temperature processing chamber 2.
On the other hand, the unloading side has a configuration opposite to that described above, and heats and raises the temperature of the material 1 to be processed in stages from the low-temperature processing chamber 2 to the take-out section 5, thereby preventing dew condensation on the material 1. can be prevented. That is, with this configuration, heat is removed from the processed material 1 and it is exposed to the atmosphere at the take-out section 5, so dew condensation on the processed material 1, which is a drawback of conventional low-temperature processes, is prevented. .

In addition, this heat removal from the material to be treated uses gradual cooling, which was a drawback of conventional techniques, rather effectively, so the desired effect can be achieved without the need for extra processes such as heating or passivation. .

Although the present invention has been applied to low-temperature etching technology in the embodiments described above, the present invention can be embodied in various other low-temperature processing technologies, such as low-temperature CvD technology.

〔Effect of the invention〕

As mentioned above, the present invention skillfully utilizes conventional cooling means to enable the conventional system to be applied as is, and is an effective method that solves problems such as dew condensation caused by rapid temperature rise of the treated material. It can be called technology.

[Brief explanation of drawings]

FIG. 1 is a block diagram schematically showing a low temperature processing apparatus according to an embodiment of the present invention. 1.11-14.11'-14'... Material to be processed (wafer), 2... Low-temperature processing chamber (low-temperature J soching process chamber), 3... Carrying-in section (loading chamber), 41- 43...
Cooling chamber, 41' to 43'... Heating chamber, 5... Removal section (unloading chamber), 61 to 63. 61' to 63'.
...Support for the material I to be processed (wafer susceptor).

Claims (1)

[Claims] 1. In a low-temperature processing apparatus that carries a material to be treated into a low-temperature treatment chamber and performs low-temperature treatment on the material in the low-temperature treatment chamber, between the loading portion of the material to be treated and the low-temperature treatment chamber. A low-temperature processing equipment that has multiple cooling chambers whose temperature is sequentially lowered toward the low-temperature processing chambers.