JP2671979B2 - Heating equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heating device used for forming a specific thin film on the surface of an IC substrate, and more particularly to shutting off a furnace body from a clean room. [Prior Art] Generally, in a semiconductor processing factory, in a low pressure CVD apparatus as a heating apparatus, the furnace body side and the clean air chamber side are partitioned by a partition, and the pressure on the clean air chamber side is set higher than the furnace body side. The unclean air on the furnace side is prevented from entering the clean air chamber side. FIG. 6 shows the structure of the front part of a conventional low pressure CVD apparatus.
Inside the heat insulating material installed in the furnace body 2, a reaction tube (outer tube) 6 for accommodating an IC substrate and performing heat treatment is installed, and an end portion of the reaction tube 6 is adjacent to the furnace body 2. It faces the clean room (scavenger) 8A installed in the room. A partition wall 10 on the side of the furnace body 2 for partitioning the clean room 8A and the furnace body 2 is provided between the clean room 8A and the furnace body 2, and a front wall 12 of the clean room 8A is fixed to the partition wall 10. In this low pressure CVD apparatus, a clean room 8 is provided for the furnace body 2 side.
In order to clean the air on the A side, the internal pressure is set high. When the air pressure in the clean room 8A is set high, unclean air does not enter from the furnace body 2 side to the clean room 8A side, but due to the pressure difference between the furnace body 2 side and the clean room 8A side. An air flow is generated from the clean room 8A side to the furnace body 2 side as indicated by an arrow a. When air convection occurs inside the furnace body 2 by such an air flow, the temperature distribution of the furnace body 2 changes, so that convection is prevented and heat dissipation from the furnace body 2 side to the clean room 8A is prevented. As a measure to do so, as shown in FIG. 6, a heat insulating material 14 that covers the reaction tube 6 is installed on the inner surface of the front wall 12 of the clean room 8A, as well as the heat insulating material 4, and the reaction tube 6
A fibrous heat insulating material 20 is packed in a gap 18 formed around the periphery of the. [Problems to be Solved by the Invention] By the way, on the clean room 8A side, an automatic cap mechanism 22 for opening / closing the reaction tube 6, an automatic opening / closing mechanism 24 for automatically driving the automatic cap mechanism 22, and a reaction tube 6 are provided. An O-ring cooling mechanism 26 that seals the end portion, a cooling mechanism 28 that cools the automatic cap mechanism 22 are installed, and a cooling water pipe that circulates cooling water to each cooling mechanism 26, 28. Various mechanisms are installed, and 30 is a connection portion of a cooling water pipe for guiding cooling water. Since various facilities are installed on the clean room 8A side in this way, there is very little space available and the clean room 8A
An elevating device for transferring an object to be processed such as an IC substrate, a cooling water pipe, an exhaust duct, and the like are installed outside the device, and a transfer means is installed on the front side thereof. Therefore, when cleaning the reaction tube 6, the work of installing the heat insulating materials 14 and 20 in the clean room 8A is very difficult spatially, the workability is poor, and the heat insulating materials 14 and 20 are installed. Even so, it is very difficult to completely block the air flow. Furthermore, when fibrous heat insulating materials 14 and 20 are used, accumulation of dust 32 has been confirmed on the lower side of the clean room 8A. This is the clean room 8A and the clean air room side where the clean room 8A is installed. May deteriorate the cleanliness of the. In the conventional case, the heat insulating material 14 is attached every time the reaction tube 6 is attached,
20 installation work is required, and the reproducibility of the temperature profile is poor depending on the installation condition, and temperature control becomes uneven. Further, in the conventional low pressure CVD apparatus, as shown in FIG. 6, since the end of the reaction tube 6 is exposed in the clean room 8A, heat is radiated at the exposed part of the inner wall of the clean room 8A and the atmosphere. It has the drawback of increasing the temperature. Therefore, an object of the present invention is to provide a heating device that omits the work of installing a heat insulating material, suppresses the generation of dust due to the heat insulating material, and the temperature increase on the clean room side, and that enables good temperature control on the furnace body side. . [Means for Solving the Problems] As shown in FIGS. 1 and 2, the heating device of the present invention includes a reaction tube (6) for accommodating an object to be heat-treated, and this reaction tube. And a furnace body (2) into which the front end opening and the rear end opening are projected from the furnace opening, and the front end opening or the rear end opening of the reaction tube formed in the furnace opening of the furnace body. Clean room (8A, 8B) that keeps parts clean
A cap mechanism (automatic cap mechanism 22, 44) installed in the clean room to open and close the reaction tube, a holding frame (36, 46) installed at the opening edge of the reaction tube, and the holding frame. An O-ring (35, 45) that is fitted to the edge of the reaction tube that is projected from and is sandwiched between the front end frame of the cap mechanism and the holding frame to hold the reaction tube in a sealed state; A cylindrical body that is installed between a closing member (heat insulating member 48, a fixed frame 50) that closes the furnace port on the outer peripheral side of the reaction tube and the holding frame and surrounds the reaction tube, and cools the periphery thereof. A water guiding pipe (38, 52) for circulating water is arranged to provide heat shielding between the reaction chamber and the cleaning chamber exposed from the furnace opening to the cleaning chamber side, and through the holding frame, Cooling jacket (34
A, 34B) and. [Operation] According to such a configuration, the reaction tube accommodating the object to be heat-treated is inserted into the furnace body with the front end opening and the rear end opening protruding from the furnace opening, and is formed in the furnace opening. A clean chamber is provided for maintaining the front end opening or the rear end opening of the reaction tube in a clean state, and the reaction tube can be opened and closed by a cap mechanism installed in the clean chamber. A holding frame is installed at the opening edge of the reaction tube, and an O-ring is fitted to the edge of the reaction tube protruding from the holding frame. The O-ring is sandwiched between the front end frame of the cap mechanism and the holding frame. This keeps the reaction tube sealed. The water-cooling jacket is a cylindrical body that is installed between the holding frame and the furnace opening and surrounds the reaction tube, and a water guiding tube that circulates cooling water is arranged around the reaction tube from the furnace opening to the clean room side. A heat shield is provided between the exposed reaction tube and the clean room, and the O-ring is cooled through the holding frame. With such a configuration, heat can be shielded between the clean room and the reaction tube, the temperature increase on the clean room side due to the opening and closing of the reaction tube can be suppressed, the air convection can be suppressed, and the furnace body side The temperature change can be suppressed, the furnace temperature can be stabilized, and the heating temperature can be easily controlled. Further, thermal deterioration of the O-ring can be prevented. Further, since the heat insulating material is not necessary, it is possible to suppress the generation of dust due to the heat insulating material and the non-uniformity of temperature control, which contributes to the improvement of the accuracy of the heat treatment. [Examples] FIG. 1 shows an example of a heating apparatus according to the present invention. This example relates to a low pressure CVD apparatus. 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. The reaction tube 6 is inserted into the heat insulating material 4 fixed inside the furnace body 2. The front end of the reaction tube 6 faces the clean room 8A and the rear end faces the clean room 8B. ing. An automatic cap mechanism 22 that opens and closes the front end of the reaction tube 6 is provided on the clean room 8A side.
As shown in FIG. 2, the automatic opening / closing mechanism 24 automatically opens and closes in the direction of arrow A. A holding frame 36 is installed on the front end edge of the reaction tube 6 with an O-ring 35 interposed, and a front end frame 37 of the automatic cap mechanism 22 is installed by gripping the O-ring 35. . Between the end portion of the reaction tube 6 and the end portion of the furnace body 2 via the holding frame 36, the exposed portion of the reaction tube 6 is covered so as to straddle these end portions, and the furnace body 2 and the clean room 8A are covered. A water cooling jacket 34 as an example of heat shielding means for isolating
A is installed. On the peripheral surface of the water cooling jacket 34A, as shown in FIG. 3, a water pipe for spirally circulating cooling water.
38 are located. As shown in FIG. 4, the water cooling jacket 34A is cooled by the circulation of the cooling water supplied as shown by the arrow C from the pipe connecting portion 40 attached to the holding frame 36 to the water guiding pipe 38, and the reaction tube Shields heat from 6. The clean room 8A has a duct exhaust port 42 for exhausting the internal air.
Is installed to purify the air. Further, on the clean room 8B side, similarly to the clean room 8A side, an automatic cap mechanism 44 for opening and closing the rear end of the reaction tube 6 is provided,
The automatic cap mechanism 44 is automatically opened and closed in the direction of arrow B, as shown in FIG. A holding frame 46 having an O-ring 45 interposed therein to keep airtightness is installed at the rear end edge of the reaction tube 6, and the front end frame 47 of the automatic cap mechanism 44 is gripped by holding the O-ring 45. is set up. At the rear end of the furnace body 2 is a heat insulating member 48 made of silica cloth or the like.
The fixed frame 50 is attached via. These fixed frames
As shown in FIG. 5, a water cooling jacket 34B is provided between the holding frame 46 and the holding frame 46 as an example of a heat shield means that cuts off the furnace body 2 and the clean room 8B from both ends. is set up. A water guide pipe 52 that circulates the cooling water in a spiral shape is arranged on the peripheral surface of the water cooling jacket 34B, and the water guide pipe 52 has a holding frame.
The cooling water supplied through the pipe connection portion 53 attached to the 46 is constantly circulated. Therefore, the water cooling jacket 34
B is cooled by the cooling water and shields heat from the reaction tube 6. 49 is an exhaust port for decompression, 54 is a water cooling jacket 34
A fixing pipe as a fixing means for fixing the water conduit 52 of B is shown. As in the clean room 8A, a duct exhaust port 56 for exhausting the internal air is installed inside the clean room B to purify the air. Reference numeral 58 is a front door on the clean room 8B side. Therefore, when the water cooling jackets 34A and 34B are installed so as to extend between the end of the furnace body 2 and the end of the reaction tube 6, between the furnace body 2 side and the clean room 8A or the clean room 8B side. Is blocked by the water cooling jackets 34A and 34B, and fluctuations in the temperature of the furnace body 2 due to convection of air can be suppressed, the control thereof is improved, and the temperature of the furnace body 2 can be stabilized. Since the exposed portions of the reaction tube 6 in the clean chambers 8A and 8B are covered with the water cooling jackets 34A and 34B, the heat radiation of the reaction tube 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 a shielding cylinder without the water conduits 38 and 52 may be used. [Effects of the Invention] As described above, according to the present invention, the following effects can be obtained. (A) A reaction tube accommodating an object to be heat-treated is introduced into a furnace body by projecting a front end opening and a rear end opening from a furnace opening, and is formed in the furnace opening to form a front end opening of the reaction tube. Or a clean room is provided to maintain the rear end opening in a clean state,
The reaction tube can be opened and closed with a cap mechanism installed in this clean room. A holding frame is installed at the opening edge of the reaction tube, and an O-ring is fitted to the edge of the reaction tube protruding from the holding frame. The O-ring is provided between the front end frame of the cap mechanism and the holding frame. And the reaction tube can be kept sealed. The water-cooling jacket is installed between the holding frame and the furnace opening to form a tubular body that surrounds the reaction tube, and a water guide tube for circulating cooling water is arranged around the tube body. Heat can be shielded between the reaction tube exposed from the furnace opening to the clean room side and the clean room, the O-ring can be cooled through the holding frame, and the air between the furnace body side and the clean room side can be cooled. The convection can be shut off and the temperature of the furnace body can be stabilized. (B) By using the water cooling jacket that circulates the cooling water by the water conduit to cool it, the heat insulating material is not required, so the work for it can be omitted and the generation of dust due to the heat insulating material can be prevented, and the clean room The cleaning of the side air can be increased. (C) Since the reaction tube exposed on the clean room side is covered by the water-cooling jacket that forms a cylindrical body, the temperature increase on the clean room side can be prevented, and the temperature rise on the clean room side can prevent adverse effects on the object to be processed and heat treatment can do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutaway sectional view showing a reduced pressure CVD apparatus which is an embodiment of a heating apparatus of the present invention, and FIG. 2 is a reduced pressure shown in FIG.
Partially cutaway sectional view showing the operation of the automatic cap mechanism of the CVD apparatus, FIG. 3 is a side view showing the outer shape of the water cooling jacket, and FIG.
5 and 5 are sectional views showing a water cooling jacket portion, and FIG. 6 is a sectional view showing a configuration of a front portion of a conventional low pressure CVD apparatus. 2 ... Furnace 6 ... Reaction tubes 8A, 8B ... Clean rooms 22, 44 ... Automatic cap mechanism 34A, 34B ... Water cooling jackets 35, 45 ... O-rings 36, 46 ... Holding frames 37, 47 ... … Front end frames 38, 52 …… Water conduit 48 …… Insulation member 50 …… Fixed frame

Claims (1)

(57) [Claims] A reaction tube for accommodating an object to be heat-treated, a furnace body into which the reaction tube projects and inserts the front end opening and the rear end opening from the furnace opening, and the reaction tube formed in the furnace opening of the furnace body. A clean room for maintaining the front end opening or the rear end opening of the reaction tube in a clean state, a cap mechanism installed in the clean room to open and close the reaction tube, and installed at an opening edge of the reaction tube The holding frame and the edge of the reaction tube protruding from the holding frame, and is sandwiched between the front end frame of the cap mechanism and the holding frame to hold the reaction tube in a sealed state. O
A ring, a tube body that is installed between the holding member that closes the furnace port on the outer peripheral side of the reaction tube and the holding frame and surrounds the reaction tube, and a water pipe that circulates cooling water around the tube. And a water cooling jacket that cools the O-ring through the holding frame while shielding heat from the reaction chamber exposed from the furnace opening to the clean chamber side and the clean chamber. A heating device characterized in that