JPS62281418A - Heating device - Google Patents

Abstract

PURPOSE:To stabilize a furnace temperature and to prevent an increase of temperature in a clean room by providing heat shielding means having a reach including both a furnace and a clean room to prevent convection of the air between the furnace side and the clean room side. CONSTITUTION:A clean room 8A is arranged at the front end of, and in touch with, a furnace 2 of a pressure-reduced CVD device. At the rear end of the furnace 2, a clean room 8B is arranged similarly. A reaction tube 6 is inserted into a heat insulating member 4 fixed to the inside of the furnace 2 and the front end of this reaction tube 6 faces the clean room 8A and the rear end faces the clean room 8B. Between the end parts of the reaction tube 6 and the end parts of the furnace 2, a water cooling jacket 34A as a heat shielding means which insulates the furnace 2 from the clean room 8A while covering an exposed part of the reaction tube 6 with its reach including said two end parts. On a periphery of the water cooling jacket 34A, a water inlet pipe 38 for circulating a cooling water spirally is arranged. The existence of the water cooling jackets 34A and 34B enables the restraint of variation of temperature of the furnace 2 caused by convection of the air, resulting in the stabilization of the temperature of the furnace 2.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a heating device used for forming a specific thin film on the surface of an IC substrate, and in particular, relates to a heating device used for forming a specific thin film on the surface of an IC substrate, and in particular, related to the blocking of

[Conventional technology]

In general, in a low-pressure CVD device used as a heating device in a semiconductor processing factory, the furnace body side and the clean air chamber side are separated by a perch joint, and the pressure on the clean air chamber side is set to be higher than that on the furnace body side. This prevents unclean air from entering the clean air chamber.

FIG. 6 shows the configuration of the front part of a conventional reduced pressure CVD apparatus.

Inside the heat insulating material 4 installed in the furnace body 2, there is a reaction tube (outer tube) that accommodates IC boards and performs heat treatment.
6 is installed, and the end of this reaction tube 6 faces a clean room (scavenger) 8A installed adjacent to the furnace body 2. A partition wall 10 on the furnace body 2 side is provided between the clean chamber 8A and the furnace body 2, and a front wall 12 of the clean chamber 8A is fixed to this partition wall 10.

In this reduced pressure CVD apparatus, the internal pressure is set high in order to clean the air on the clean chamber 8A side with respect to the furnace body 2 side. If the air pressure in the clean room 8A is set high, no unclean air will enter the clean room 8A from the furnace body 2 side, but due to the pressure difference between the furnace body 2 side and the clean room 8A side. , an air current is generated from the clean room 8A side to the furnace body 2 side as shown by arrow a.

When air convection occurs inside the furnace body 2 due to such airflow, the temperature distribution of the furnace body 2 changes, so this convection is prevented, and heat radiation from the furnace body 2 side to the clean room 8A is also prevented. As a measure to prevent this, as shown in FIG. 6, a heat insulating material 14 is installed on the inner surface of the front wall 12 of the clean room 8A to cover the reaction tube 6 in the same way as the heat insulating material 4, and also to cover the reaction tube 6. A fibrous heat insulating material 20 is placed in the gap 18 created around the periphery of the
is packed.

[Problem that the invention seeks to solve]

By the way, on the clean room 8A side, there is an automatic capping mechanism 22 that opens and closes the reaction tube 6, an automatic opening and closing mechanism 24 that automatically drives the automatic capping mechanism 22, and a cooling O-ring that seals the end of the reaction tube 6. A cooling mechanism 28 for cooling the mechanism 26 and the automatic capping mechanism 22 is installed, and various mechanisms such as cooling water piping for circulating cooling water to each cooling mechanism 26.28 are installed. is the connection part of the cooling water piping that leads the cooling water.

Since various types of equipment are installed on the clean room 8A side, there is very little space available.
On the outside of A, an elevating device for transferring objects to be processed such as IC boards, cooling water piping, exhaust ducts, etc. are installed on its side, and a transfer means is installed on its front side.

Therefore, when cleaning the reaction tube 6, installing the heat insulating material 14.20 in the clean room 8A is very spatially difficult and has poor workability.
Even if 0 is installed, it is very difficult to completely block the airflow.

Furthermore, when using a heat insulating material such as fibrous material 14.20,
It has been confirmed that dust 32 has accumulated on the lower side of the clean room 8A,
This may cause deterioration of the cleanliness of the clean room 8A and the clean air chamber in which the clean room 8A is installed.

Conventionally, each time a reaction tube 6 is attached, a heat insulating material 14.
20 installation operations are required, and the reproducibility of the temperature profile is poor depending on the installation state, making temperature control variable.

In addition, in the conventional low-pressure CVD apparatus, as shown in FIG. 6, the end of the reaction tube 6 is exposed in the clean chamber 8A, and the heat dissipated from the exposed portion causes the inner wall of the clean chamber 8A to be exposed to the atmosphere. It has the disadvantage of increasing temperature.

Therefore, the present invention aims to provide a heating device that eliminates the work of installing a heat insulating material, suppresses the generation of dust caused by the heat insulating material and the temperature rise in the clean room side, and improves the temperature control on the furnace body side. .

[Means for solving problems]

As shown in FIGS. 1 and 2, the heating device of the present invention has an end portion of the furnace body 2 and a portion protruding from the furnace body 2 inside the clean chambers 8A and 8B provided adjacent to the furnace body 2. A heat shielding means (water cooling jackets 34A, 34B) is provided to cover the periphery of the reaction tube 6 and cut off the furnace body 2 side and the clean chambers 8A, 8B side. It was installed.

[For production]

With this configuration, the furnace body 2 side and the clean room 8A.

8B side and heat shielding means (water cooling jacket l-34A, 34
B), there is no need to install a heat insulating material 14, 20 between the furnace body 2 and the clean rooms 8A, 8B as in the conventional case.
), it is possible to suppress the temperature rise in the clean rooms 8A and 8B, and it is also possible to suppress air convection between the furnace body 2 and the clean rooms 8A and 8B side, suppressing temperature changes in the furnace body 2 and improving its control. It can be carried out. Moreover, insulation material 14.20
Omission of the insulation material 14 eliminates the need for its installation work.
．． 20 is installed, problems such as generation of dust 32 and uneven temperature control can be prevented.

In the heating device of this invention, the heat shielding means is
If it is configured with water-cooled jackets (34A and 34B) in which cooling water is circulated around the outer circumference of the end of the reaction tube 6, the furnace body 2 side and the clean room 8A
, 8B side, and the cooling effect of the water cooling jackets 34A, 34B allows the clean room 8A, 8B side to be easily shut off.
8B temperature rise can be suppressed.

〔Example〕

FIG. 1 shows an embodiment of a heating device of the present invention, and this embodiment relates to a low pressure CVD device.

As shown in FIG. 1, a clean room 8A is installed adjacent to the furnace body 2 at its front end, and at the rear end of the furnace body 2,
Similarly, a clean room 8B is installed. A reaction tube 6 is inserted into the inside of the heat insulating material 4 fixed inside the furnace body 2, and the front end of this reaction tube 6 faces the clean room 8A, and the rear end faces the clean room 8B. ing.

On the clean chamber 8A side, an automatic capping mechanism 22 for opening and closing the front end of the reaction tube 6 is provided.
is automatically opened and closed in the direction of arrow A by an automatic opening and closing mechanism 24, as shown in FIG.

A holding frame 36 is installed at the front edge of the reaction tube 6 with an O-ring 35 interposed therebetween, and a front end frame 37 of the automatic capping mechanism 22 is installed by gripping the O-ring 35. . Between the end of the reaction tube 6 and the end of the furnace body 2 via the holding frame 36, the exposed part of the reaction tube 6 is covered by spanning between these two ends, and the furnace body 2 and the clean chamber 8A are connected. Water-cooled salmon throat 34A is an example of a heat shielding means that blocks the connection between
is installed. On the circumferential surface of the water cooling jacket 34A,
As shown in FIG. 3, a water guide pipe 38 is provided to circulate cooling water in a spiral manner. As shown in FIG. 4, the water cooling jacket 34A is cooled by the circulation of cooling water supplied to the water conduit 38 from the piping connection part 40 attached to the holding frame 36 as shown by arrow C, and 6. Shield the heat from 6. A duct exhaust port 42 for exhausting internal air is installed in the clean room 8A to purify the air.

Further, on the clean chamber 8B side, an automatic capping mechanism 44 for opening and closing the rear end of the reaction tube 6 is provided as in the clean chamber 8A side, and as shown in FIG. Automatically opens and closes in the direction of. A holding frame 46 with an O-ring 45 interposed therebetween to maintain airtightness is installed at the rear end of the reaction tube 6, and the front end frame 47 of the automatic camping mechanism 44 is held by gripping the O-ring 45. is set up. A fixed frame 50 is attached to the rear end of the furnace body 2 via a heat insulating member made of silica cloth or the like. As shown in FIG. 5, between the fixed frame 50 and the holding frame 46, a water cooling device is provided as an example of a heat shielding means that spans both ends of these and isolates between the furnace body 2 and the clean room 8B. A jacket 34B is installed. water cooling jacket 3
On the circumferential surface of 4B, there is a water guide pipe 5 that circulates cooling water in a spiral shape.
2 is disposed, and cooling water supplied to the water guide pipe 52 via a pipe connection part 53 attached to the holding frame 46 is constantly circulated. Therefore, the water-cooled jacket 34B is cooled by the cooling water and shields the heat from the reaction tube 6.

Reference numeral 49 indicates an exhaust port for reducing pressure, and reference numeral 54 indicates a fixing pipe as a fixing means for fixing the water conduit pipe 52 of the water cooling jacket 34B.

Similarly to the clean room 8A, a duct exhaust port 56 for exhausting internal air is installed inside the clean room 8B to purify the air. Note that 58 is a front door on the clean room 8B side.

Therefore, if the water-cooled jacket l-34A, 34B is installed across the end of the furnace body 2 and the end of the reaction tube 6, the furnace body 2 side and the clean room 8A or clean room 8B side The space between the two water-cooled cages 34A and 34B is cut off by the water-cooled cages 34A and 34B, suppressing fluctuations in the temperature of the furnace body 2 due to air convection, improving control, and stabilizing the temperature of the furnace body 2. .

Since the exposed portions of the reaction tubes 6 in the clean chambers 8A and 8B are covered by the water cooling jackets 34A and 34B, heat radiation from the reaction tubes 6 can be suppressed, and the influence on the temperature profile of the upper furnace can be prevented.

In the embodiment, the water cooling jackets 34A and 34B constitute the heat shielding means, but the heat shielding means may be constituted by a shielding tube without the water conduit pipes 38, 52.

[Effects of the Invention] As explained above, according to the present invention, the following effects can be obtained.

(a) Instead of conventional heat insulating material, a heat shielding means is installed across both the furnace body side and the clean room side, so it is possible to block air convection between the furnace body side and the clean room side, and the furnace body Temperature can be stabilized.

(bl) Since no heat insulating material is installed, the work for that purpose can be omitted, and the generation of dust due to the heat insulating material can be prevented, improving the cleanliness of the air in the clean room side.

(C) Since the portion of the reaction tube exposed to the clean chamber is covered by a heat shielding means, the temperature rise in the clean chamber can be prevented;
It is possible to prevent the adverse effects of temperature rise in the clean room.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the heating device according to the present invention using a low-pressure CVD method.
FIG. 2 is a partially cutaway sectional view showing the operation of the automatic camping mechanism of the reduced pressure CVD apparatus shown in FIG. 1; FIG. 3 is a side view showing the outer shape of the water cooling jacket;
4 and 5 are cross-sectional views showing the water cooling jacket portion, and FIG. 6 is a cross-sectional view showing the structure of the front part of a conventional reduced pressure CVD apparatus. 2...Furnace body, 6...Reaction tube, 8A, 8B...Clean room, 34A, 34B...Water cooling jacket as heat shielding means. Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) Inside a clean room provided adjacent to the furnace body, cover the reaction tube by spanning between the end of the furnace body and the end of the reaction tube protruding from the furnace body, A heating device characterized in that a heat shielding means is installed to isolate the furnace body side and the clean room side. (2) The heating device according to claim 1, wherein the heat shielding means is constituted by a water cooling jacket in which cooling water is circulated around the outer periphery of the end of the reaction tube.