JPS63257219A - Vertical treatment apparatus - Google Patents

Abstract

PURPOSE:To prevent attachment of foreign material to a material to be treated even if the foreign material falls due to friction between members or thermal fatigue of the members, by covering a guiding region, which inputs and takes out the material to be treated, with a dustproof cover. CONSTITUTION:An input/output region B, which is located beneath a reacting tube 2, is covered with a dustproof cover 17. Thus attachment of falling foreign material 16 to the surface of a wafer 5 is prevented when the wafer 5 is inputted and taken out. An exhaust pipe 13, which is connected to the reacting tube 2, is linked with an overlapped structure having a specified interval. When reacting gas 4 from a treating region S is exhausted, the concentration of the reacting gas 4 can be made low. A part between the dustproof cover 17 and the reacting tube 2 has a labyrinth structure, and an exhausting chamber D and the input/output region B are communicated. Thus intrusion of the foreign material into the input/output region B from the exhausting chamber D is prevented. In this way, the vertical treating apparatus having high treating reliability can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a technology that is effective when applied to heat treatment technology, such as surface treatment of semiconductor wafers (hereinafter simply referred to as wafers) in the manufacture of semiconductor devices. is available for use.

[Conventional technology]

An example of a processing device with a vertical structure used for wafer processing is given in "Electronic Materials 1984 Special Issue, VLSI Manufacturing and Testing Equipment Guidebook J, P2O", published by Kogyo Chosenkai Co., Ltd., November 29, 1984. There are things listed.

The above literature describes the advantages of vertically structured processing equipment, such as the fact that its structure has high strength even when wafers have a large diameter, and that it is easy to load and unload wafers, making it easier to automate work. Various points have been explained about how it is suitable for use.

The present inventor has studied ways to improve the reliability of the vertical processing apparatus. Although the following is not a publicly known technique, it is a technique studied by the present inventor, and its outline is as follows.

As a means of chemically processing the surface of a wafer, an oxide film forming apparatus, CVD (Chemical Vapor
r Dep.

Although it is common to use a processing device called a 5ition) device or a diffusion device, vertical installation is preferred due to ease of automation, small floor space occupied by the device, and advantageous structural strength. Types of reaction tubes have been attracting attention.

A possible processing device with such a vertical structure is one in which a long quartz reaction tube with a closed top end is installed vertically, and the reaction tube is surrounded by a heat insulator and a heating means. Some devices allow wafers to be inserted and removed from the bottom of the reaction tube.

[Problem that the invention seeks to solve]

However, in the processing apparatus having a vertical structure, as the temperature increases, sliding friction occurs between the constituent members due to differences in coefficients of thermal expansion, which may generate minute foreign matter.

Each of the above-mentioned microscopic foreign objects freely falls downward from the gap between the reaction tube and the heating means, etc., but in vertical processing equipment, these falling foreign objects may adhere to the wafer surface when loading and unloading wafers. , there is a possibility that it will be drawn into the processing area due to convection caused by the pressure difference with the outside.

The inventor has revealed that this is likely to cause wafer processing defects.

On the other hand, when a highly corrosive and highly concentrated reactive gas is used as a processing fluid, the main problem is how to discharge this reactive gas while maintaining a high level of safety. Revealed by the inventor.

The present invention has been made focusing on the above problems,
The purpose is to provide vertical processing technology that prevents foreign matter from adhering to objects to be processed during loading and unloading, and enables highly reliable processing by discharging processing fluid in a highly safe manner. It's about doing.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

A brief overview of typical inventions disclosed in this application is as follows.

That is, a reaction tube is provided with a processing fluid supply means and an exhaust means for the processing region, and the material to be processed is taken in and out of the processing region from the lower opening end, and the The apparatus has a vertical processing apparatus structure including a heating means for heating a processing area, and a dustproof cover that isolates an inlet/output area of the processed material provided at the lower end of the opening of the reaction tube from the outside.

[Effect]

According to the above-mentioned means, since the entry/exit area where the workpiece is taken in and out is covered with a dustproof cover, even if foreign matter falls due to friction between members or thermal fatigue, it will not fall onto the workpiece. It is possible to prevent the material from being deposited on the surface of the material, and to prevent processing defects that occur when the material to be processed is taken in and taken out.

In addition, if outside air is taken in when exhausting the processing fluid from the exhaust pipe, the concentration of the processing fluid can be diluted.
It becomes possible to discharge the processing fluid with high safety.

〔Example〕

FIG. 1 is an explanatory diagram showing a diffusion device that is an embodiment of the present invention.

This embodiment is a so-called diffusion device 1 that forms a diffusion layer on the surface of a wafer, and has a reaction tube 2 in which a processing area S is formed.

The reaction tube 2 is made of quartz, for example, and has a structure in which the upper end is closed in a dome shape and the lower end is open.

Above the processing area S inside the reaction tube 2, a processing fluid supply pipe 3 led from the outside through the lower end of the reaction tube 2 and the inside of the processing area S is opened to the processing area S. , whereby the reaction gas 4 as a processing fluid is supplied to the processing region S.
The structure is such that it is supplied with

In the processing area S, a plurality of wafers 5 as objects to be processed are
It is held by a jig 6 at a predetermined interval so as to be parallel to the cross-sectional direction of the width of the reaction tube 2. This jig 6 is constructed integrally with a sealing lid 7 attached to the lower opening end of the reaction tube 2, and in a state where the sealing lid 7 closes the opening lower end of the reaction tube 2, the jig 6 The structure is such that the wafer 5 is located within the processing area S.

There are soaking tubes 8 at regular intervals around the reaction tube 2.
is attached, and a heater 10 as a heating means is further provided on the outer periphery thereof. The heat soaking tube 8 is
For example, the heater 10 is made of silicon carbide, etc.
The structure is such that the processing area S inside the reaction tube 2 is heated by secondary radiant heat generated by heating from the reaction tube 2 to achieve predetermined diffusion conditions. Note that silicon carbide, which constitutes the soaking tube 2, has the property of blocking heavy metal atoms, so the heater 10
It is also possible to prevent foreign atoms generated from the above from entering into the processing area S.

The upper end of the heater 10 is covered with a heat insulator 11 made of ceramic wool, for example, to prevent heat dissipation above the diffusion device 1.

The lower part of the diffusion device 1 is covered with a heat exhaust pipe 12, and the inside of the heat exhaust pipe 12 is separated from the outside as an exhaust chamber. The lower end of the reaction tube 2 is installed so as to penetrate into the exhaust chamber, and an exhaust pipe 13 is connected to one side of the reaction tube 2 inside the exhaust chamber. This exhaust pipe 13 passes through the exhaust chamber to the reaction gas 4 in the processing area S.
The structure is such that the air is exhausted to the outside. The exhaust pipe 13 is
In the exhaust chamber, as shown in FIG. 2, a small diameter exhaust pipe 13a and a large diameter exhaust pipe 13b are connected in an overlapping structure with a constant interval. Therefore, when the reaction gas 4 is discharged, the structure is such that the exhaust gas in the exhaust chamber is also taken in. For this reason, for example, highly corrosive HCj2 or P OCj! Since the reaction gas 4 such as No. 3 is diluted in concentration and discharged to the outside, safety in exhausting can be ensured.

Further, the exhaust chamber is in communication with the space formed between the upper soaking tube 8 and the reaction tube 2, and there is a cross-sectional abbreviation between this space A and the exhaust chamber. A dustproof member 15 having a shape is provided on the side of the soaking tube 8. Therefore, even if a foreign object 16 is generated due to contact between members such as the soaking tube 8, the heater 10, and the heat insulator 11, this falling foreign object 1
6 is captured by the dustproof member 15, and the falling foreign matter 16 is suppressed from falling into the exhaust chamber.

On the other hand, inside the exhaust chamber is an exhaust pipe 19 to the factory exhaust treatment system.
The structure is such that the interior of the room is exhausted by being connected to the

A dustproof cover 17 is provided at the center of the interior of the exhaust chamber, and a space surrounded by this dustproof cover 17 is formed as an entry/exit area B for the wafer 5. This dustproof cover 17 has a taber 1 whose diameter becomes larger as it goes downward.
7a and a cylindrical sleeve 7b, which is connected to the heat exhaust pipe 12 at the lower end of the sleeve 17b.

By the way, the dust cover 17 provided in the exhaust chamber
The positional relationship between the reaction tube 2 and the reaction tube 2 will be explained as follows.

The lowermost end of the reaction tube 2 has two flanges F1 and F2 that protrude diagonally outward, and a dust cover 17
The upper tip E of is both flanges F.

The positional relationship is such that it enters between F2 in a non-contact manner. That is, the exhaust chamber and the wafer 5 introduction/intake area B are in communication with each other through a labyrinth structure.

By maintaining the communication state between the exhaust chamber and the exhaust chamber 13, the entrainment of minute foreign matter into the processing zone S due to the pressure difference between the exhaust chamber 13 and the exhaust chamber 13 is prevented. Prevented.

Further, since the reaction tube 2 and the dustproof cover 17 are not in contact with each other, generation of minute foreign matter due to friction between members due to thermal stress can be prevented. Furthermore, since the lead-in/out area B and the exhaust chamber are communicated with each other through a labyrinth structure, even if there is a foreign object 16 that has fallen into the exhaust chamber from the space without being captured by the falcon-proofing member 15, Therefore, it is possible to prevent the foreign matter 16 from further entering the outlet/inlet area from the exhaust chamber.

Note that the lower end of the lead-in/out area B is open to the outside of the opening, and clean air 18 flows in a laminar flow around the opening, preventing foreign matter such as dust from entering from the outside. has been done.

Next, the operation of this embodiment will be explained.

First, when the sealing lid 7 is attached to the lower end of the opening of the reaction tube 2 with a predetermined number of wafers 5 held in the jig 6, the processing area S and the lead-in/out area B inside the reaction tube 2 are closed. It will be in a blocked state. In this state, when the treatment zone S reaches a predetermined temperature condition by the heater 10, the reaction gas 4 is supplied into the treatment zone S from the treatment fluid supply pipe 3. When the treatment area S is filled with the atmosphere of the reaction gas 4, a predetermined diffusion reaction occurs on the surface of the sea urchin/X5.

In this way, when a certain process is completed, the sealing lid 7 is removed and the wafer 15 is removed together with the jig 6 into the lead-in/out area B.
is lowered to the position. At this time, as described above, since the lead-in/out area B is covered by the dustproof cover 17, the falling foreign matter 16 caused by friction or thermal stress between members such as the soaking tube 8 and the heat insulator 11 is prevented. 1. Even if the foreign matter 16 falls to the exhaust chamber, it is effectively prevented from entering the entry/exit area B.

Therefore, there is no risk that the wafer 5 will be contaminated during such loading and unloading of the wafer 5.

As described above, according to this embodiment, the following effects can be obtained.

(1) By covering the introduction/input region B located below the reaction tube 2 with the dustproof cover 17, it is possible to prevent the falling foreign matter 16 from adhering to the surface of the wafer 5 when the wafer 5 is taken in and out.

[2] By connecting the exhaust pipes 13 connected to one reaction tube 2 in an overlapping structure having a constant interval, the concentration of the reaction gas 4 can be diluted when the reaction gas 4 is discharged from the processing area S. .

(3) By creating a labyrinth structure: 1 between the dustproof cover 17 and the reaction tube 2, and thereby communicating the exhaust chamber and the outlet/inlet area B, shopping from the exhaust chamber to the outlet/inlet area B is carried out. Intrusion can be prevented.

(4) Since the lead-in/out area B and the exhaust chamber are communicated with each other, the pressure difference in the rain space is alleviated, and foreign matter is prevented from entering the lead-in/out area B and even the processing area S due to entrainment of airflow. Ru.

(5) By extending the lower end of the first reaction tube 2 into the exhaust chamber, the thermal influence from the high temperature processing zone S can be alleviated.

(6) According to (1) to (5) above, it is possible to provide a vertical processing technique with high processing reliability.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.゛In the above explanation, the invention made by the present inventor was mainly applied to the field of application, which is a so-called diffusion device, but the invention is not limited to this, for example, oxide film formation, CVD or annealing. etc,
It can also be applied to processing devices that perform other processing.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

In other words, it is a reaction tube that has a processing area inside, is equipped with means for supplying processing fluid and exhaust means for this processing area, and in which the material to be processed is introduced into and taken out from the lower end of the opening. , a vertical dustproof cover provided at the lower end side of the opening of the reaction tube to isolate the introduction/intake area of the processed material from the outside, a heating means provided around the reaction tube to heat the processing area; By using a mold processing apparatus, it is possible to prevent processing defects of the processing target due to adhesion of fallen objects, and it is possible to improve processing reliability.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view showing a diffusion device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a connected state of an exhaust pipe in the embodiment. DESCRIPTION OF SYMBOLS 1... Diffusion device, 2... Reaction tube, 3... Processing fluid supply pipe, 4... Reaction gas (processing fluid), 5... Wafer (processed object), 6... Treatment Ingredients, 7...Sealing lid, 8.
... Soaking tube, 10... Heater, 11... Heat insulator,
12... Heat exhaust pipe, 13.13a, 13b... Exhaust pipe, 14... Exhaust, 15... Dust-proof member, 1G...
Foreign matter, 17... Dust cover, 17a... Taber part,
17b...Sleeve, 18...Clean air, 19
...Exhaust pipe, 20...N2 gas supply nozzle, A.
... Space, B... Lead-in/exit area, D... Exhaust chamber, E...
・Dustproof cover upper tip, Fl, F2...flange, S
...processing area. Figure 1 / /-Hanging strawberry tree''-

Claims (1)

[Claims] 1. A vertical processing device that processes a workpiece using a processing fluid supplied into a processing region in a heated environment, which has a processing region inside and a reaction tube, which is equipped with a processing fluid supply means and an exhaust means, and through which the material to be processed is introduced into and taken out of the processing area from the lower opening end; and a heater provided around the reaction tube to heat the processing area. and a dust-proof cover that isolates an inlet/outlet area for the to-be-processed material provided at the lower end side of the opening of the reaction tube from the outside. 2. The vertical processing apparatus according to claim 1, wherein an exhaust chamber is provided around the dustproof cover to exhaust heat from the introduction/intake area. 3. The exhaust means for the processing area is an exhaust pipe connected to the reaction tube, and the exhaust pipe takes in outside air together with the processing fluid in the processing area and discharges it to the exhaust system. Vertical processing equipment as described in section.