JP5432461B2 - Vertical furnace equipment - Google Patents

Description

  The present invention relates to a vertical furnace apparatus in which a plurality of silicon substrates and glass substrates are arranged in multiple stages along a vertical direction to perform heat treatment.

  The semiconductor manufacturing process includes a heat treatment for heating a substrate such as a silicon substrate or a glass substrate at a high temperature. As an apparatus for performing heat treatment on a substrate, a vertical furnace apparatus that stores a plurality of substrates arranged in multiple stages in the vertical direction is used. In the vertical furnace apparatus, a heater for heating the inside of the process tube is arranged around the process tube containing a plurality of substrates in a predetermined processing atmosphere, and a liner for temperature equalization is provided between the process tube and the heater. A tube is placed. The process tube is openable and closable at the bottom, and a plurality of substrates are carried into and out of the process tube using the bottom of the vertical furnace as the furnace port.

  The substrate before and after the heat treatment is put in and out of the furnace port of the vertical furnace apparatus. However, if the heat of the heater acts on the substrate before and after the heat treatment, an appropriate heat treatment cannot be performed. Further, when the heat of the heater leaks to the outside, it becomes difficult to efficiently maintain the temperature in the process tube at a predetermined processing temperature, and workability is reduced due to an increase in environmental temperature.

Therefore, a heat-resistant and heat-insulating member is disposed around the furnace port of the vertical furnace apparatus in order to prevent heat leakage from the gap between the heater and the process tube. A heat-resistant and heat-insulating member disposed around the furnace port of a conventional vertical furnace apparatus is made of silica fiber, silica-based ceramic fiber, or the like (see, for example, Patent Document 1).
JP 2002-319546 A

  However, since the conventional vertical furnace apparatus used silica fiber or silica-based ceramic fiber as a heat-resistant heat insulating member around the furnace port, the fiber peels off due to changes over time at a temperature of about several hundred degrees Celsius, In addition to impairing the heat insulating properties around the furnace port, there are problems of fouling the substrate around the furnace port and before and after processing. For the same reason, the conventional vertical furnace apparatus has a problem that it cannot be used for heat treatment such that the temperature around the furnace port becomes 1000 ° C. or higher. This is presumably because amorphous silica or silica-based ceramic has a relatively low crystallization temperature, and crystallizes and becomes brittle at the temperature around the furnace opening during heat treatment.

  The object of the present invention is to prevent leakage of heat from around the furnace port by making the shape around the furnace port and the material of the high heat-resistant heat insulating member appropriate, and at the temperature around the furnace port during heat treatment. Vertical type that can be used for heat treatment that prevents the fiber from peeling from the high heat-resistant heat insulating member, does not cause high temperature and fouling around the furnace opening, and the temperature around the furnace opening becomes 1000 ° C or higher. It is to provide a furnace apparatus.

The vertical furnace apparatus according to the present invention includes a process tube, a heater, a liner tube, a support, and at least one high heat resistant heat insulating member. The process tube has a cylindrical shape with an open bottom. The heater surrounds the periphery of the process tube except the lower end with a gap. The liner tube is disposed between the heater and the process tube. The support has a hole through which the process tube passes, and supports the intermediate portion in the vertical direction of the process tube, the lower end of the heater, and the lower end of the liner tube. The high heat-resistant heat insulating member is an annular body made of SiC long fibers and is divided into two parts each having a semicircular arc shape, and suppresses heat conduction from the process tube, the heater, and the liner tube to the support.
The heater has a heat insulating portion at the lower end portion, and further includes a holding member that holds the lower end portion of the liner tube, and the high heat resistant heat insulating member is between the inner peripheral surface of the heat insulating portion, the outer peripheral surface of the holding member, and the upper surface of the support. Including a first high heat-resistant heat insulating member. The process tube has a flange portion at an intermediate portion in the vertical direction on the outer peripheral surface, and the high heat resistant heat insulating member includes a second high heat resistant heat insulating member disposed between the flange portion and the bottom surface of the support. The support includes a heater base and a skirt that sandwich the flange portion up and down, and the second high heat-resistant heat insulating member includes a member disposed between the bottom surface of the heater base and the top surface of the flange portion, a bottom surface of the flange portion, And a member disposed between the upper surface of the skirt.

  In this configuration, the heat conduction from the process tube, the heater, and the liner tube to the support that supports the intermediate portion in the vertical direction of the process tube, the lower end portion of the heater, and the lower end portion of the liner tube is composed of SiC long fibers. It is suppressed by the high heat resistant heat insulating member of the annular body. The crystallization temperature of SiC is sufficiently higher than the temperature of the support that receives heat conduction from the process tube, heater, and liner tube during heat treatment. Therefore, the high heat-resistant heat insulating member does not become brittle due to changes over time and does not lose flexibility, so that the fibers do not peel from the high heat-resistant heat insulating member, and the heat insulating property around the furnace port is maintained, The substrate around the furnace opening and the substrate before and after processing are not soiled.

In this configuration, the heater have a heat insulating portion at the lower end portion provided with a holding member for holding the lower end of the liner tube, the inner circumferential surface of the heat insulating portion of high heat insulation member, the outer peripheral surface of the holding member and the support It is arranged between the upper surfaces.

  The high heat-resistant heat insulating member can reliably close the gap generated between the heat insulating portion of the heater and the holding member of the liner tube, and heat conduction from the gap between the heater and the process tube to the support can be suppressed. .

Further, the process tube have a flange portion in an intermediate portion in the vertical direction of the outer peripheral surface, the support is provided with a heater base and skirt to sandwich the flange portion up and down, a high temperature insulation member, a heater base bottom and the flange portion between the upper surface of, and because of the arrangement between the bottom and the upper surface of the skirt of the flange portion, it is possible to suppress the heat conduction to the support from the process tube.

  According to the present invention, the shape around the furnace port and the material of the heat-resistant heat insulating member can be made appropriate, and it is possible to reliably prevent the leakage of heat from around the furnace port and at the temperature around the furnace port during heat treatment. It is possible to prevent the fibers from peeling from the heat-resistant and heat-insulating member. As a result, the temperature around the furnace port does not increase and fouling occurs, and it can be used for heat treatment where the temperature around the furnace port becomes 1000 ° C. or higher.

  FIG. 1 is a schematic cross-sectional view of a vertical furnace apparatus according to an embodiment of the present invention. The vertical furnace apparatus 10 includes a process tube 1, a heater 2, a liner tube 3, and a support 4. A substrate loading / unloading portion is formed below the vertical furnace apparatus 10.

  The process tube 1 has, for example, a cylindrical shape with a bottom surface made of quartz. A flange portion 11 is formed at an intermediate portion in the vertical direction on the outer peripheral surface of the process tube 1. A boat having a plurality of substrates arranged in multiple stages in the vertical direction is carried into and out of the process tube 1 from the furnace port on the bottom.

  The heater 2 surrounds the periphery of the process tube 1 except for the lower end with a gap. Therefore, the heater 2 also has a cylindrical shape with an open bottom. The heater 2 is driven so that the internal temperature of the process tube 1 becomes a predetermined processing temperature.

  The liner tube 3 is disposed on the tube of the process tube 1 and the heater 2. Accordingly, the liner tube 3 also has a cylindrical shape with an open bottom. The liner tube 3 causes the heat from the heater 2 to uniformly act on the outer surface of the portion excluding the lower end portion of the process tube 1.

  The support 4 supports the process tube 1, the heater 2, and the liner tube 3. A hole 41 is formed in the support 4. The process tube 1 passes through the hole 41 from below. The support 4 supports the lower end of the heater 2 and the lower end of the liner tube 3 on the upper surface. The support 4 supports the flange portion 11 of the process tube 1 on the bottom surface.

  FIG. 2 is a sectional view around the furnace port of the vertical furnace apparatus. In the figure, hatching is omitted except for the main part.

  The support 4 includes a frame 42, a heater base 43, a liner base 44, and a skirt 45. Both the heater base 43 and the liner base 44 have an annular shape. The heater base 43 is attached to the upper surface of the frame 42. The inner diameter of the heater base 43 is larger than the inner diameter of the liner base 44 and smaller than the outer diameter of the liner base 44. The liner base 44 is attached to the bottom surface of the heater base 43. The inside of the liner base 44 is a hole 41.

  A lower end portion of the heater 2 is fixed to the upper surface of the heater base 43 via the metal fitting 22. The heater 2 has a heat insulating portion 5 formed at the lower end. The metal fitting 22 is screwed to the heat insulating portion 5.

  The liner tube 3 is placed on the upper surface of the liner base 44 via an annular holding member 6. The holding member 6 holds the lower end portion of the liner tube 3. The outer peripheral surface of the holding member 6 faces the inner peripheral surface of the heat insulating portion 5.

  The outer diameter of the holding member 6 is smaller than the inner diameter of the heat insulating portion 5. For this reason, a gap 61 is formed between the heat insulating portion 5 and the holding member 6 over the entire circumference. A recess 5 </ b> A is formed in the lower part of the inner peripheral surface of the heat insulating part 5 over the entire circumference. The super ring 7 is fitted in the recess 5A over the entire circumference.

  The super ring 7 is the first high heat-resistant heat insulating member of the present invention, and is formed in a semicircular arc shape as shown in FIGS. 3A and 3B using, as an example, a SiC long fiber. The super ring 7 has an outer diameter substantially equal to the diameter of the peripheral surface of the recess 5 </ b> A, and an inner diameter substantially equal to the outer diameter of the holding member 6. The super ring 7 is longer than the concave portion 5A in the vertical direction.

  Therefore, when the two super rings 7 are fitted into the recess 5A, the outer peripheral surface, inner peripheral surface, upper surface and bottom surface of the super ring 7 are the peripheral surface of the recess 5A, the outer peripheral surface of the holding member 6, and the upper surface of the recess 5A, respectively. And press-contact with the upper surface of the heater base 43. As a result, the gap 61 is closed, and the heat between the heater 2 and the liner tube 3 can be prevented from leaking from the gap 61 to the outside.

  Since the super ring 7 has a semicircular arc shape, a part of the liner tube support 44 is removed so that the process tube 1, the heater 2 and the liner tube 3 are supported by the support 4 and can be attached to and detached from the recess 5A. It is.

  The support 4 supports the process tube 1 by sandwiching the flange portion 11 between the liner tube support 44 and the skirt 45. The cushion 8 is disposed between the bottom surface of the liner tube support 44 and the top surface of the flange portion 11, and the cushion 9 is disposed between the top surface of the skirt 45 and the bottom surface of the flange portion 11.

  The cushions 8 and 9 are second heat-resistant heat insulating members of the present invention, and are formed in an annular shape as shown in FIGS. 4A and 4B using SiC long fibers as a material. The skirt 45 has an annular shape and is attached to the frame 42 via an attachment member (not shown). 4 (A) and 4 (B) show the cushion 8, the cushion 9 also has the same shape as the cushion 8 only with a different diameter.

  The outer diameter of the process tube 1 is smaller than the inner diameters of the holding member 6 and the liner base 44, and there is no gap between the outer peripheral surface of the process tube 1 and the inner peripheral surface of the holding member 6 and the inner peripheral surface of the liner base 44. A gap is formed around the circumference. On the other hand, the outer diameter of the flange portion 11 is larger than the inner diameters of the holding member 6 and the liner base 44, and the cushion 8 is disposed between the upper surface of the flange portion 11 and the bottom surface of the liner base 44 over the entire circumference.

  The cushion 8 is in close contact with the upper surface of the flange portion 11 and the bottom surface of the liner base 44 due to flexibility. Therefore, it is possible to suppress the heat between the process tube 1 and the liner tube 3 from leaking outside between the liner base 44 and the flange portion 11.

  The cushion 9 is disposed between the bottom surface of the flange portion 11 and the top surface of the skirt 45 over the entire circumference. The cushion 9 is in close contact with the bottom surface of the flange portion 11 and the top surface of the skirt 45 by flexibility.

  The flange portion 11 is sandwiched between the liner base 44 and the skirt 45 with the cushions 8 and 9 having flexibility therebetween. For this reason, when vibration is applied to the vertical furnace apparatus 10, the vibration is buffered by the cushions 8 and 9 and does not directly propagate to the flange portion 11, so that the flange portion 11 and the process tube 1 may be damaged. Absent.

  The crystallization temperature of SiC, which is the material of the super ring 7 and the cushions 8 and 9, is sufficiently higher than the temperature around the furnace port during the heat treatment, and the super ring 7 and the cushions 8 and 9 can be used even after long-term use. There is no loss of flexibility. Therefore, heat leakage between the heater 2 and the liner tube 3 by the super ring 7 is prevented, heat leakage between the process tube 1 and the liner tube 3 by the cushion 8, and the process tube 1 by the cushions 8 and 9 is performed. Can be prevented over a long period of time.

  In addition, the leakage of heat from around the furnace port can be surely prevented, and the fibers can be prevented from peeling off from the high heat-resistant heat insulating member under the temperature around the furnace port during heat treatment. There is no increase in temperature around the furnace port, and the substrate before and after the heat treatment located at the loading / unloading portion below the furnace port is not soiled. Furthermore, it is possible to cope with heat treatment such that the temperature around the furnace port is 1000 ° C. or higher.

  The super ring 7 and the cushions 8 and 9 can be configured by covering an internal blanket material with a cloth material on the surface. In this case, at least the cloth material is composed of SiC long fibers.

  The above description of the embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

It is sectional drawing which shows the outline of the vertical furnace apparatus which concerns on embodiment of this invention. It is sectional drawing around the furnace port of the same vertical furnace apparatus. (A) And (B) is the top view and front view of a super ring used for the vertical furnace apparatus. (A) And (B) is the top view and front view of a cushion which are used for the vertical furnace apparatus.

Explanation of symbols

1-process tube 2-heater 3-liner tube 4-support 5-heat insulating part 6-holding member 7-super ring (first high heat-resistant heat insulating member)
8-cushion (second heat-resistant insulation member)
9-cushion (second high heat-resistant insulation member)
10-vertical furnace apparatus 11-flange part 41-hole part 42-frame 43-heater base 44-liner base 45-skirt

Claims (1)

A cylindrical process tube with an open bottom;
A heater that surrounds the periphery of the process tube except for a lower end portion with a gap;
A liner tube disposed between the heater and the process tube;
A support body having a hole through which the process tube passes, and a support body for supporting an intermediate part in the vertical direction of the process tube, a lower end part of the heater, and a lower end part of the liner tube;
The process tube, constructed by at least one high temperature insulation member for suppressing heat conduction to the two-piece exhibiting respective semicircular consists of long fibers of SiC with respect to the support from the heater and the liner pipe A high heat-resistant insulation member ,
The heater has a heat insulating portion at the lower end,
A holding member for holding the lower end of the liner tube;
The high heat resistant heat insulating member is composed of SiC long fibers, and includes a first high heat resistant heat insulating member disposed between an inner peripheral surface of the heat insulating portion, an outer peripheral surface of the holding member, and an upper surface of the support. ,
The process tube has a flange portion at an intermediate portion in the vertical direction on the outer peripheral surface,
The high heat-resistant heat insulating member includes a second high heat-resistant heat insulating member made of SiC long fibers and disposed between the flange portion and the support,
The support includes a heater base and a skirt that sandwich the flange portion up and down,
The second high heat resistant heat insulating member includes a member disposed between the bottom surface of the heater base and the top surface of the flange portion, and a member disposed between the bottom surface of the flange portion and the top surface of the skirt. A vertical furnace device.

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