JP4820137B2 - Heating element holding structure - Google Patents

Description

  The present invention relates to a heating element holding structure, an insulating structure, a heating apparatus, and a substrate processing apparatus, and more particularly to a technique for holding a pair of power feeding portions of a heating element, for example, a semiconductor integrated circuit device (hereinafter referred to as an IC). .) CVD apparatus, oxide film formation apparatus, diffusion apparatus, and carrier activation after ion implantation for depositing (depositing) an insulating film, a metal film, and a semiconductor film on a semiconductor wafer (hereinafter referred to as a wafer) The present invention relates to a semiconductor device that is effective for use in a semiconductor manufacturing apparatus such as a heat treatment apparatus (furnace) used for thermal treatment such as reflow or annealing for planarization or annealing.

In an IC manufacturing method, a batch type vertical hot wall diffusion / CVD apparatus is widely used to perform a film forming process and a diffusion process on a wafer.
In general, a batch-type vertical hot wall type diffusion / CVD apparatus (hereinafter referred to as a CVD apparatus) is composed of an inner tube that forms a processing chamber into which a wafer is carried and an outer tube that surrounds the inner tube, and is installed vertically. A process tube, a boat that holds a plurality of wafers to be processed and carries them into the inner tube processing chamber, a gas introduction pipe that introduces a source gas into the inner tube, and an exhaust that exhausts the inside of the process tube And a heater unit that is provided outside the process tube and heats the inside of the process tube.
Then, after a plurality of wafers are held vertically aligned by the boat and loaded into the inner tube from the bottom furnace port (boat loading), the source gas is introduced into the inner tube from the gas introduction pipe At the same time, the inside of the process tube is heated by the heater unit. As a result, a CVD film is deposited on the wafer and a diffusion process is performed.

In a conventional CVD apparatus of this type, the heater unit, which is a heating apparatus, is formed into a long cylindrical shape that covers the entire process tube by a vacuum foam (vacuum adsorption molding) method using a heat insulating material such as alumina or silica. A heat-insulating wall body, a heating element formed of an iron-chromium-aluminum (Fe-Cr-Al) alloy or molybdenum silicide (MoSi ₂ ), and a case covering the heat-insulating wall body. The heating element is provided on the inner periphery of the heat insulating wall.

In such a heater unit, for example, when rapid heating at 30 ° C./min or more is performed, a heating element formed in a plate shape is used in order to increase the effective heat generation area.
And when this plate-shaped heat generating body is used, the electric power feeding part for energizing this heat generating body is comprised as follows.
Both ends of the plate-shaped heating element are bent at right angles in the thickness direction to form a pair of power feeding parts, respectively, and the pair of power feeding parts penetrates the heat insulating wall body, and the through part of the power feeding part is further perpendicular. The power supply terminal is connected to the bent portion. The pair of power feeding portions are held by an insulator to prevent the power feeding portion from being exposed to thermal expansion during heat generation. For example, see Patent Document 1.
JP 2004-39967 A

In the above-described heating element holding structure, since the narrower is more advantageous in terms of heating distribution, the interval between the pair of power feeding portions of the heating element is often set narrow.
However, when the interval between the pair of power feeding portions of the heating element is set to be narrow, both ends of the heating element are close to each other.
On the other hand, when the temperature rises, the heating element expands due to thermal expansion. Moreover, a heat generating body also tends to extend even if it is used for a long time.
When the heating element is extended, the distance between both ends of the heating element is narrowed, so that the distance between the pair of power feeding portions of the heating element is narrowed. If it is high, they will be welded together.

An object of the present invention is to provide a heating element holding structure capable of preventing the heating element from being short-circuited or welded and extending the life of the heating element.
The second object of the present invention is to provide an insulating structure capable of preventing the heating element from being short-circuited or welded and extending the life of the heating element.
A third object of the present invention is to provide a heating device that can prevent the heating element from being short-circuited or welded and extend the life of the heating element.
A fourth object of the present invention is to provide a substrate processing apparatus capable of preventing the heating element from being short-circuited or welded and extending the life of the heating element.

Typical means for solving the above-described problems are as follows.
(1) A heating element holding structure used in a substrate processing apparatus,
A heat insulating wall formed in a cylindrical shape;
A heating element having a cylindrical portion provided in a cylindrical shape along the inner peripheral side of the heat insulating wall, and a pair of power feeding portions provided so as to penetrate the heat insulating wall at the end of the cylindrical portion; ,
Holding of a heating element having at least a part provided between the pair of power feeding parts and another part extending beyond the inner peripheral surface of the cylindrical part to reach the inside of the cylindrical part Structure.
(2) A heating element of a heating device used in a substrate processing apparatus has a cylindrical cylindrical portion and a pair of power feeding portions provided at ends of the cylindrical portion, and the gap between the pair of power feeding portions. An insulating structure for isolation,
An insulating structure having a partition wall portion that separates the pair of power supply portions from between the pair of power supply portions to the inside of the cylindrical portion beyond a position on a circumferential surface of the cylindrical portion.
(3) The heating element of the heating device used in the substrate processing apparatus has a cylindrical cylindrical portion and a pair of power feeding portions provided at the ends of the cylindrical portion, and the gap between the pair of power feeding portions. An insulating structure for isolation,
An insulating structure having a partition wall that reaches between the pair of power feeding portions to a position on a circumferential surface of the cylindrical portion and isolates the pair of power feeding portions.
(4) A pair of power feeding portions of the heating element is provided so as to penetrate a heat insulating wall formed on an outer peripheral side of the cylindrical portion, and two insulating members separate from the heat insulating wall are provided. The insulating structure according to (2).
(5) A pair of power feeding portions of the heating element is provided so as to penetrate a heat insulating wall formed on an outer peripheral side of the cylindrical portion, and two insulating members separate from the heat insulating wall are provided. The insulating structure according to (3).
(6) A pair of power feeding portions of the heat generating body is provided so as to penetrate a heat insulating wall formed on the outer peripheral side of the cylindrical portion, and is separate from the heat insulating wall and separate from the heat insulating wall. (2) (3) Insulation structure which has the outer side insulation member provided in the outer side.
(7) A pair of power feeding portions of the heating element is provided so as to penetrate a heat insulating wall formed on an outer peripheral side of the cylindrical portion, has the partition wall, and is separate from the heat insulating wall. The insulating structure according to (2) or (3), further comprising an inner insulating member provided inside the heat insulating wall.
(8) The insulating structure according to (4) or (5), further including an inner insulating member provided inside the heat insulating wall and an outer insulating member provided outside the heat insulating wall.
(9) The insulating structure according to (4), (5), (6), (7), or (8), wherein the insulating member has a hardness higher than that of the heat insulating wall.
(10) The insulating structure according to (4), (5), (6), (7), (8), or (9), wherein the insulating member has higher bending strength than the heat insulating wall.
(11) A heating element of a heating device used in a substrate processing apparatus has a cylindrical cylindrical portion and a pair of power feeding portions provided at ends of the cylindrical portion, and the gap between the pair of power feeding portions An insulating structure for isolation,
In the power feeding part provided so that the pair of power feeding parts penetrates the heat insulating wall formed on the outer peripheral side of the cylindrical part, the pair of power feeding parts is separated from the pair of power feeding parts. Insulation structure provided outside.
(12) The insulating structure according to (11), which has higher hardness, bending strength, or density than the heat insulating wall.
(13) A heating element of a heating device used in a substrate processing apparatus includes a cylindrical cylindrical portion and a pair of power supply portions provided at ends of the cylindrical portion, and the pair of power supply portions are An insulating structure provided inside or outside the heat insulating wall so as to isolate the pair of power supplying portions in a power supplying portion provided so as to penetrate the heat insulating wall formed on the outer peripheral side of the cylindrical portion Body,
An insulating structure having a higher hardness, bending strength, or density than the heat insulating wall.
(14) The insulating structure according to any one of (2) to (13), wherein a pair of holding grooves for holding the pair of power feeding units is provided.
(15) The insulating structure according to (14), wherein the holding groove is formed to be cut out to reach the uppermost part or the lowermost part of the insulating structure.
(16) A heating device having the insulating structure according to any one of (2) to (15).
(17) A substrate processing apparatus having the heating device of (16).
(18) The heat generating body holding structure according to (1), wherein the heat generating body includes a pair of connection portions connected to the pair of power feeding portions and provided outside the heat insulating wall body.
(19) The insulating structure according to (2) or (3), wherein the heating element has a pair of connection portions connected to the pair of power feeding portions.
(20) The insulating structure according to (4) to (13), wherein the heating element is connected to the pair of power feeding portions, and has a pair of connection portions provided outside the heat insulating wall body.
(21) A heating device having the insulating structure according to (19) or (20).
(22) A substrate processing apparatus having the heating device of (21).

  According to the means (1) described above, even if the heating element is thermally expanded, it is possible to prevent the pair of power feeding portions from coming into contact with each other. be able to.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  In the present embodiment, the heating element holding structure according to the present invention is a book installed in a CVD apparatus (batch type vertical hot wall type reduced pressure CVD apparatus) which is an embodiment of the substrate processing apparatus according to the present invention. It is used for the heater unit which is one embodiment of the heating device according to the invention.

As shown in FIG. 1, a CVD apparatus according to an embodiment of a substrate processing apparatus of the present invention includes a vertical process tube 11 that is vertically arranged and fixedly supported. Reference numeral 11 denotes an outer tube 12 and an inner tube 13.
The outer tube 12 is integrally formed in a cylindrical shape using quartz (SiO ₂ ), and the inner tube 13 is integrally formed in a cylindrical shape using quartz (SiO ₂ ) or silicon carbide (SiC).
The outer tube 12 is formed in a cylindrical shape having an inner diameter larger than the outer diameter of the inner tube 13 and closed at the upper end and opened at the lower end. The outer tube 12 is covered with a concentric circle so as to surround the outer side of the inner tube 13.
The inner tube 13 is formed in a cylindrical shape whose upper and lower ends are open, and the cylindrical hollow portion of the inner tube 13 has a processing chamber 14 into which a plurality of wafers held in a state of being vertically aligned by the boat 22 are loaded. Forming. The lower end opening of the inner tube 13 constitutes a furnace port 15 for taking in and out the wafer.

A lower end portion between the outer tube 12 and the inner tube 13 is hermetically sealed by a manifold 16 formed in a circular ring shape, and the manifold 16 is used for replacement of the inner tube 13 and the outer tube 12 for the purpose of replacement. Removably attached to the tube 13 and the outer tube 12, respectively.
Since the manifold 16 is supported by the heater base 19 of the CVD apparatus, the process tube 11 is vertically installed.

An exhaust pipe 17 is connected to the upper part of the side wall of the manifold 16, and the exhaust pipe 17 is connected to an exhaust device (not shown) so that the processing chamber 14 can be evacuated to a predetermined degree of vacuum. Yes. The exhaust pipe 17 is in a state of communicating with a gap formed between the outer tube 12 and the inner tube 13, and an exhaust path 18 is configured by the gap between the outer tube 12 and the inner tube 13. The exhaust passage 18 has a circular ring shape with a constant cross-sectional shape.
Since the exhaust pipe 17 is connected to the manifold 16, the exhaust pipe 17 is formed in a cylindrical hollow body and is disposed at the lowermost end portion of the exhaust path 18 formed long in the vertical direction.

  A seal cap 20 that closes the lower end opening is brought into contact with the manifold 16 from the lower side in the vertical direction. The seal cap 20 is formed in a disk shape substantially equal to the outer diameter of the outer tube 12, and is lifted and lowered in the vertical direction by a boat elevator 21 (only a part of which is shown) provided outside the process tube 11. It is comprised so that.

On the center line of the seal cap 20, a boat 22 for holding the wafer 1 as a substrate to be processed is vertically supported and supported.
The boat 22 is configured to hold a plurality of wafers 1 so that the wafers 1 are aligned horizontally and aligned with each other.

  A gas introduction pipe 23 is connected to the seal cap 20 so as to communicate with the furnace port 15 of the inner tube 13. The gas introduction pipe 23 is connected to a raw material gas supply device and a carrier gas supply device (both not shown). It is connected. The gas introduced from the gas introduction pipe 23 into the furnace port 15 flows through the processing chamber 14 of the inner tube 13, passes through the exhaust path 18, and is exhausted from the exhaust pipe 17.

Outside the outer tube 12, a heater unit 30, which is a heating device according to the present embodiment that heats the inside of the process tube 11, is installed concentrically so as to surround the outer tube 12.
The heater unit 30 includes a case 31 made of stainless steel (SUS) and having a cylindrical shape with a closed upper end and a lower end opening. The inner diameter and the full length of the case 31 are larger than the outer diameter and the full length of the outer tube 12. Is set.
A cylindrical heat insulation wall 33 larger than the outer diameter of the outer tube 12 is installed inside the case 31 concentrically with the outer tube 12. A gap 32 between the heat insulating wall 33 and the inner peripheral surface of the case 31 is a space for air cooling.

The heat insulating wall 33 includes a disk-shaped ceiling wall 34 having an outer diameter smaller than the inner diameter of the case 31, and a cylindrical side wall having an inner diameter larger than the outer diameter of the outer tube 12 and an outer diameter smaller than the inner diameter of the case 31. Part 35.
The ceiling wall portion 34 is covered so as to close the opening at the upper end of the side wall portion 35, and the upper end surface of the ceiling wall portion 34 is provided in contact with the lower surface of the ceiling wall of the case 31.
In addition, you may comprise the exhaust port which penetrates the ceiling wall part 34 and the ceiling wall of case 31, and forcibly air-cooling the atmosphere between the heat insulation wall 33 and the outer tube 12.
By setting the outer diameter of the side wall portion 35 to be smaller than the inner diameter of the case 31, a gap 32 as an air cooling space is formed between the side wall portion 35 and the case 31.
A through hole is provided in the side wall portion 35 of the heat insulating wall 33 so as to penetrate the space between the gap 32, the heat insulating wall 33 and the outer tube 12, and the atmosphere between the heat insulating wall 33 and the outer tube 12 is provided. May be configured to be forced to air-cool.
And the side wall part 35 of the heat insulation wall 33 is constructed | assembled as one cylinder by stacking the several heat insulation block 36 in the orthogonal | vertical direction.

As shown in FIG. 1 and FIG. 2, the heat insulating block 36 includes a doughnut-shaped main body 37 having a short cylindrical shape, and the main body 37 is an insulating material such as fibrous or spherical alumina or silica (insulating). A heat insulating material that also functions as a material) is used, and is integrally formed by a vacuum foam method mold.
The heat insulating block 36 and the main body 37 are divided into a plurality of cylinders in the circumferential direction. For example, the heat insulating block 36 and the main body 37 are molded in a state where the cylinder is divided into a plurality of parts at a predetermined angle, and then assembled into a cylinder. Good.
In this case, since play (ease of movement) is also formed in the heat insulating block 36, it is difficult to break even if stress is applied to the heat insulating block 36. Preferably, the size may be divided into four.
At the lower end of the main body 37, a coupling male part (convex part) 38 is formed in a state where a part of the inner periphery of the main body 37 is cut out into a circular ring shape. A coupling female portion (concave portion) 39 is formed on the upper end portion of the main body 37 in a state where a part of the outer periphery of the main body 37 is cut out into a circular ring shape.
In addition, a protruding portion 37 a protruding inward is formed on the inner peripheral side of the upper end of the main body 37.
Between the protrusions 37a of the adjacent upper and lower heat insulation blocks 36, an attachment groove (concave part) 40 for attaching a heating element is in a state where the inner peripheral surface of the side wall part 35 is cut out in a circular ring shape. It is formed at a certain depth and a certain height. One mounting groove 40 is formed for each heat insulating block 36 and has one closed circular shape.
On the inner peripheral surface of the mounting groove 40, as shown in FIG. 3B, there are a plurality of scissors-shaped holders 41 for positioning and holding the heating element. Attached to the interval.

For the heating element 42, a resistance heating material such as Fe—Cr—Al alloy, MOSi ₂ and SiC is used. As shown in FIG. 3A, the heating element 42 has a corrugated flat plate shape. Moreover, the upper side wave part 42a and the upper side clearance 43a, and the lower side wave part 42b and the lower side clearance 43b are formed alternately. These are integrally formed by pressing or laser cutting.
The heating element 42 is provided in a circular ring shape along the inner periphery of the heat insulating block 36. The outer diameter of the circular ring shape formed by the heating element 42 is slightly smaller than the inner diameter (the diameter of the inner peripheral surface) of the mounting groove 40 of the heat insulating block 36.
As described above, the cylindrical portion 51 of the heating element 42 having a circular ring shape is formed.
As shown in FIGS. 1 to 3, the cylindrical portion 51 of the heating element 42 is provided for each mounting groove 40 of the heat insulating block 36. On the upper and lower stages, cylindrical portions 51 of other adjacent heating elements 42 are provided separately.
As shown in FIGS. 3 (a) and 3 (b), a plurality of holders 41, 41 are arranged so as to straddle from the lower end of the upper gap 43a to the upper end of the lower gap 43b. Inserted. Thus, the heating element 42 is held in a state of being separated from the inner peripheral surface of the mounting groove 40.
As shown in FIGS. 2 and 3, a pair of power feeding portions 45, 46 are provided at both ends 44, 44 of the cylindrical portion 51 of the heating element 42, which are perpendicular to the circumferential direction of the circular ring shape and have a radius. Each of them is bent outward in the direction. A pair of connecting portions 47 and 48 are formed at the distal ends of the pair of power feeding portions 45 and 46, respectively, so as to be bent at right angles to the power feeding portions 45 and 46 so as to be opposite to each other.
In order to suppress a decrease in the amount of heat generated in the pair of power supply units 45 and 46, the interval between the pair of power supply units 45 and 46 is set small.
Preferably, the portions where the pair of power feeding portions 45 and 46 are bent from the circumferential direction of the circular ring shape at right angles outward in the radial direction are near the uppermost portion of the upper wave portion 42a of the heating element 42 or the lower wave portion. It may be near the lowermost part of 42b.
By doing so, the heating element 42 can be spread over the pair of power feeding portions 45 and 46 without any gap.

A pair of insertion grooves 49 and 50 are respectively formed in the cylindrical heat insulating block 36 corresponding to the positions of the pair of power feeding portions 45 and 46. Both insertion grooves 49 and 50 are formed so as to reach the outer peripheral side of the main body 37 in the radial direction of the cylindrical shape from the mounting groove 40 side. The feeding grooves 45 and 46 are inserted into the insertion grooves 49 and 50, respectively.
The insertion grooves 49 and 50 are formed so that both the insertion grooves 49 and 50 become a single insertion groove, including between both the insertion grooves 49 and 50, before the both feeding portions 45 and 46 are inserted. In addition, after inserting both the power feeding portions 45 and 46, the heat insulating wall 33 and the insertion are inserted by filling a heat insulating material that also functions as an insulating material such as fibrous or spherical alumina or silica between the power feeding portions 45 and 46. Grooves 49 and 50 may be formed.
An insulator (hereinafter referred to as an outer insulator) 52 as an outer insulating member, which is an example of an insulating structure, is provided at both insertion grooves 49 and 50 on the outer peripheral surface of the main body 37.
The outer insulator 52 is an example of an insulating structure, and a ceramic as a heat-resistant insulating material such as alumina or silica is used, and the hardness and bending strength are higher than those of the heat insulating block 36 by an appropriate manufacturing method such as a sintering method. And the density can be increased. For example, the outer insulator 52 can have higher hardness, bending strength, and density by increasing the content of the alumina component than the heat insulating block 36.
As shown in FIG. 4A, the outer insulator 52 is substantially square, and is integrally formed in a flat plate shape having a slight curved surface R1 corresponding to the curved surface of the outer peripheral surface of the heat insulating block 36. And is fixed to the outer peripheral surface of the main body 37.
The outer insulator 52 has at least a hardness equal to or higher than that of the heat insulating block 36, a bending strength equal to or higher than that of the heat insulating block 36, and a density equal to or higher than that.
Preferably, when the hardness of the outer insulator 52 is higher than the hardness of the heat insulating block 36, the ramping of the heating element 42 can be effectively suppressed.
Preferably, when the bending strength and / or density of the outer insulator 52 is made higher than the bending strength and / or density of the heat insulating block 36, the rampage of the heating element 42 can be effectively suppressed.
A pair of holding grooves 53 and 54 are formed in the upper part of the outer insulator 52 as insertion parts for inserting a pair of power feeding parts. The positions of both holding grooves 53 and 54 correspond to the positions of both insertion grooves 49 and 50 so as to be substantially the same position. Both power feeding portions 45 and 46 inserted into both insertion grooves 49 and 50 are inserted and held in both holding grooves 53 and 54, respectively.
Preferably, as shown in FIG. 4A, the holding grooves 53 and 54 are formed so as to be cut out to reach the uppermost part of the outer insulator 52. This is because it is possible to attach or replace the outer insulator 52 after installing the pair of power feeding units. However, the holding grooves 53 and 54 can be formed in a hole shape without being cut out to the uppermost part of the outer insulator 52.
Both holding grooves 53, 54 of the outer insulator 52 hold the power feeding portions 45, 46 of the heating element 42, so that the ramping of the heating element 42 can be suppressed. The distance between the holding grooves 53 and 54 is the same as the distance between the both insertion grooves 49 and 50 of the main body 37.
Here, rampage of the heat generating element 42 means that the heat generating element 42 undergoes thermal expansion by supplying power to the heat generating element 42, or heat shrinkage occurs by stopping the power supply. It is a phenomenon that moves like moving, twisting or twisting.

An insulator (hereinafter referred to as an inner insulator) 55 as an inner insulating member, which is an example of an insulating structure, is brought into contact with and fixed to portions corresponding to both the insertion grooves 49 and 50 on the inner peripheral surface of the mounting groove 40. ing.
The inner insulator 55 is an example of an insulating structure, and a ceramic as a heat-resistant insulating material such as alumina or silica is used, and the hardness and bending strength are higher than those of the heat insulating block 36 by an appropriate manufacturing method such as a sintering method. And the density can be increased. For example, the inner insulator 55 can have higher hardness, bending strength, and density by increasing the content of the alumina component than the heat insulating block 36.
As shown in FIG. 4B, the inner insulator 55 is substantially square and has a flat plate shape having a slight curved surface R2 corresponding to the curved surface of the inner peripheral surface of the mounting groove 40 of the heat insulating block 36. It is integrally molded.
The inner insulator 55 has at least a hardness equal to or higher than that of the heat insulating block 36, a bending strength equal to or higher than that of the heat insulating block 36, and a density equal to or higher than that.
Preferably, when the hardness of the inner insulator 55 is higher than the hardness of the heat insulating block 36, the rampage of the heating element 42 can be effectively suppressed.
Preferably, if the bending strength and / or density of the inner insulator 55 is higher than the bending strength and / or density of the heat insulating block 36, the ramping of the heating element 42 can be effectively suppressed.
A pair of holding grooves 56 and 57 are formed in the upper part of the inner insulator 55 as insertion parts for inserting a pair of power feeding parts. The positions of both holding grooves 56 and 57 correspond to the positions of both insertion grooves 49 and 50 so as to be substantially the same position. Both power feeding portions 45 and 46 inserted into the both insertion grooves 49 and 50 are inserted and held in the both holding grooves 56 and 57, respectively.
Preferably, as shown in FIG. 4B, the holding grooves 56 and 57 are formed so as to be cut out to reach the uppermost part of the inner insulator 55. This is because the inner insulator 55 can be attached or exchanged after the pair of power feeding portions 45 and 46 are installed. However, the holding grooves 56 and 57 can be formed in a hole shape without being cut out to the uppermost part of the inner insulator 55.
Both holding grooves 56 and 57 of the inner insulator 55 can suppress the ramping of the heating element 42 by holding the power feeding portions 45 and 46 of the heating element 42. The interval between the holding grooves 56 and 57 is made to correspond to the insertion grooves 49 and 50 of the main body 37 and is the same interval.
On the inner end surface of the inner insulator 55 (the end surface opposite to the heat insulating block 36, that is, the end surface on the cylindrical portion 51 side of the heating element 42), a pair of power feeding portions 45 of the heating element 42 between the holding grooves 56, 57, A partition wall 58 is provided to separate 46 and the cylindrical portion 51. The partition wall 58 has a thickness (t) that is provided at least up to a position on the inner peripheral surface of the cylindrical portion 51 of the heating element 42 when abutting and fixing to the inner peripheral surface of the mounting groove 40.
Preferably, as shown in FIG. 2, when the partition wall portion 58 is provided and fixed so as to be in contact with the inner peripheral surface of the mounting groove 40, it extends beyond the inner peripheral surface of the cylindrical portion 51 of the heating element 42 into a cylinder. It is good to set it as the thickness (t) provided to the inside of the part 51. By doing in this way, a pair of electric power feeding parts 45 and 46 and the cylindrical part 51 of the heat generating body 42 can be effectively separated.
The height (h) of the partition wall 58 is set to a value or dimension (h) that is at least equal to or greater than the plate width of the heating element 42 when abutting and fixing to the inner peripheral surface of the mounting groove 40. . Further, the pair of power feeding portions 45, 46 are provided at the same height as the holding grooves 56, 57 so that the pair of power feeding portions 45, 46 can be placed at the same height so as to separate the pair of power feeding portions 45, 46 of the heating element 42. ing.
Preferably, the height (h) of the partition wall portion 58 is such that the cylindrical portion 51 of the heating element 42 has a height (h) when it is provided and fixed so as to contact the inner peripheral surface of the mounting groove 40 as shown in FIG. It may be larger than the value (h1) between the height of the uppermost portion of the upper side wave portion 42a and the height of the lowermost portion of the lower side wave portion 42b. By doing in this way, a pair of electric power feeding parts 45 and 46 and the cylindrical part 51 can be separated effectively.
The partition wall portion 58 is provided with curved portions R3 formed on both sides from the inner end surface of the inner insulator 55. By providing the curved portion R3, the inner insulator 55 can be easily formed, the strength of the inner insulator 55 is increased, the cylindrical portion 51 of the heating element 42 expands and extends, and the inner insulator 55 is in contact with the partition wall 58. The insulator 55 is difficult to break.
Note that the curved portion R3 is not limited to a curved shape, and may be a tapered shape including a flat surface.

As shown in FIGS. 2 and 3, a power supply terminal 61 is welded to one connecting portion (hereinafter referred to as a positive connecting portion) 47 of the upper heating element 42, and the other connecting portion. (Hereinafter, it is referred to as a minus side connecting portion.) 48 is welded to the upper end portion of the crossover wire 62. The lower end portion of the crossover 62 is connected to the plus side connecting portion 47 of the lower heating element 42.
Therefore, the plus side connecting portion 47 of the lower heating element 42 is located immediately below the minus connecting portion 48 of the upper heating element 42, and the cylindrical portion 51 of the lower heating element 42 is correspondingly increased. Both end portions 44, 44 are shifted in the circumferential direction from both end portions 44, 44 of the cylindrical portion 51 of the upper heating element 42.
The crossover wire 62 is formed in a round bar shape with a circular cross section using a resistance heating material such as Fe—Cr—Al alloy, MOSi ₂ and SiC in order to suppress heat dissipation from the surface of the crossover wire 62 to a small extent. Has been. However, depending on the current capacity of the connecting wire, the connecting wire 62 may be formed in a square bar shape with a square cross section.

  As shown in FIGS. 2 and 5, terminals that cover both the connecting portions 47 and 48 and the crossover wire 62 are located at positions corresponding to the installation locations of the power supply terminals 61 on the outer peripheral surface of the case 31 of the heater unit 30. A case 63 is covered, and the inside of the terminal case 63 is filled with a heat insulating material 64 such as glass wool. A plurality of power supply terminals 61 are inserted into the terminal case 63 via insulators 65.

  Next, a film forming process in a method for manufacturing a semiconductor device such as an IC using the CVD apparatus according to the above configuration will be briefly described.

As shown in FIG. 1, when a plurality of wafers 1 are loaded (wafer charging) into the boat 22, the boat 22 holding the plurality of wafers 1 is lifted by the boat elevator 21 and processed in the processing chamber 14. Is loaded (boat loading).
In this state, the seal cap 20 is in a state where the lower end opening of the manifold 16 is sealed.

The process tube 11 is evacuated through an exhaust pipe 17 so that the inside of the process tube 11 has a predetermined pressure (degree of vacuum).
In addition, the inside of the process tube 11 is heated by the heater unit 30 so as to reach a predetermined temperature. At this time, the state of energization to the heating element 42 of the heater unit 30 is feedback controlled based on the temperature information detected by the temperature sensor 24 so that the inside of the processing chamber 14 has a predetermined temperature distribution.
Subsequently, when the boat 22 is rotated by the rotation mechanism 25, the wafer 1 is rotated.

Next, the raw material gas controlled to a predetermined flow rate is introduced into the processing chamber 14 through the gas introduction pipe 23.
The introduced source gas rises in the processing chamber 14, flows out from the upper end opening of the inner tube 13 to the exhaust path 18, and is exhausted from the exhaust pipe 17.
The source gas contacts the surface of the wafer 1 as it passes through the processing chamber 14. At this time, a thin film is deposited on the surface of the wafer 1 by a thermal CVD reaction.

  When a preset processing time elapses, an inert gas is supplied from an inert gas supply source (not shown), the inside of the processing chamber 14 is replaced with the inert gas, and the pressure in the processing chamber 14 is constantly maintained. Return to pressure.

Thereafter, the seal cap 20 is lowered by the boat elevator 21, the lower end of the manifold 16 is opened, and the processed wafer 1 is held by the boat 22, so that the lower end of the manifold 16 is placed outside the process tube 11. Unload (boat unloading).
Thereafter, the processed wafer 1 is taken out from the boat 22 (wafer discharge).

By the way, when the temperature rises, the heating element 42 of the heater unit 30 expands due to thermal expansion. Further, the heating element 42 tends to be extended even when used for a long time.
For example, as shown in FIG. 6A, since the distance between the pair of power feeding portions 45 and 46 of the heating element 42 is set narrow, when the heating element 42 extends, When the interval of 46 becomes narrow and contacts at the end, it may be electrically short-circuited or welded to each other when the temperature is high.
In particular, as shown in FIGS. 3A and 3B, it is necessary to provide the insertion grooves 49 and 50 and the inner insulator 55 in the vicinity of the power feeding portion, so that the holder 41 holds the cylindrical portion 51 of the heating element 42. Thus, since the heating element 42 is likely to extend in the circumferential direction, the above-described problem is likely to occur.
In addition, the holder 41 may be cracked, come out of the heat insulating block 36, or may be displaced in the circumferential direction of the cylindrical portion 51 due to the rampage of the heating element 42. Also in this case, the distance between the pair of power feeding portions 45 and 46 is narrowed, and when they are finally contacted, they may be electrically short-circuited or welded to each other when the temperature is high.
However, in the present embodiment, the pair of power feeding portions 45 and 46 are held in a state of being insulated from each other by the outer insulator 52 and the inner insulator 55, and between the power feeding portions 45 and 46 in the inner insulator 55 and Since the partition wall portion 58 is provided radially inward from the cylindrical portion 51, as shown in FIG. 6B, even when the heating element 42 is extended, the pair of power feeding portions 45, 46 is provided. It is possible to prevent the cylinder portions 51 and the cylindrical portions 51 from coming into contact with each other, and it is possible to prevent the heating element 42 from being short-circuited or welded.

  According to the embodiment, the following effects can be obtained.

1) When the heating element is extended by holding the pair of feeding parts of the heating element with the outer and inner insulators, and by providing the inner insulator with a partition that prevents contact between both feeding parts and the cylindrical part of the heating element Even so, it is possible to prevent the pair of power feeding portions and the cylindrical portion of the heating element from coming into contact with each other, so that a short circuit and welding of the heating element can be prevented in advance.

2) The life of the heating element can be extended by preventing the heating element from being short-circuited or welded.

3) Since the contact between the pair of power feeding portions of the heating element and the cylindrical portion when the heating element is extended can be prevented, the pair of power feeding portions can be brought closer to each other compared to the case where the present invention is not used. . As a result, it is possible to suppress the temperature decrease at the power feeding unit without the heating element to the minimum.

  Needless to say, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, the inner insulator 55 having the partition wall portion 58 may be formed integrally with the main body 37 of the heat insulating block 36 that constructs the heat insulating wall body, or may be formed integrally with the integral heat insulating wall body 33. Good.

The partition wall portion 58 is not limited to being formed integrally with the inner insulator 55, but may be provided on the main body 37 of the heat insulating block 36 or the integral heat insulating wall body 33 for constructing the heat insulating wall body.
The holding grooves 56 and 57 of the inner insulator 55 are not limited to being formed on the upper side, but may be formed on the lower side of the inner insulator 55.
Similarly, the holding grooves 53 and 54 of the outer lever 52 are not limited to be formed on the upper side, but may be formed on the lower side of the outer lever 52, respectively.
That is, the insulating structure according to the present invention having the partition wall may be constituted by an insulator that is a separate insulating member from the heat insulating wall, or may be constituted by the heat insulating wall itself.

The heating element holding structure according to the present invention can be applied not only to a heater unit of a CVD apparatus, but also to heating apparatuses such as an oxide film forming apparatus, a diffusion apparatus, and an annealing apparatus.
Furthermore, the heating apparatus according to the present invention is not limited to the CVD apparatus, but can be applied to all substrate processing apparatuses such as an oxide film forming apparatus, a diffusion apparatus, and an annealing apparatus.

It is front sectional drawing which shows the CVD apparatus which is one embodiment of this invention. It is a plane sectional view showing the principal part of the heater unit which is one embodiment of the present invention. The main part of the holding | maintenance structure of the heat generating body which is one embodiment of this invention is shown, (a) is the expanded view seen from the inner side, (b) is the plane cross section in alignment with the bb line of (a). FIG. 4C is a side sectional view taken along line cc in FIG. (A) is a perspective view which shows the outer side insulator which is one Embodiment of the insulation structure which concerns on this invention, (b) is a perspective view which similarly shows an inner side insulator. It is a perspective view of a heater unit. It is each outer plane sectional drawing which shows the effect | action of contact prevention, (a) has shown the case of the comparative example, (b) has shown the case of this Embodiment, respectively.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wafer (substrate), 11 ... Process tube, 12 ... Outer tube, 13 ... Inner tube, 14 ... Processing chamber, 15 ... Furnace, 16 ... Manifold, 17 ... Exhaust pipe, 18 ... Exhaust passage, 19 ... Heater base , 20 ... Seal cap, 21 ... Boat elevator, 22 ... Boat, 23 ... Gas introduction pipe, 24 ... Temperature sensor, 25 ... Rotation mechanism, 30 ... Heater unit (heating device), 31 ... Case, 32 ... Gap, 33 ... Insulating wall (insulating structure), 34 ... ceiling wall, 35 ... side wall, 36 ... heat insulating block, 37 ... main body, 37a ... projection, 38 ... coupling male part (convex part), 39 ... coupling female part ( (Recess), 40 ... mounting groove (recess), 41 ... holder, 42 ... heating element, 42a ... upper wave portion, 42b ... lower wave portion, 43 ... gap, 43a ... upper gap, 43b ... lower gap, 44 ... Both ends, 45, 4 ... Feeding part, 47, 48 ... Connection part, 49, 50 ... Insertion groove, 51 ... Cylindrical part, 52 ... Outer insulator (insulating structure), 53, 54 ... Holding groove, 55 ... Inner insulator (insulating structure), 56, 57 ... holding groove, 58 ... partition wall part, 61 ... feeding terminal, 62 ... crossover, 63 ... terminal case, 64 ... heat insulating material, 65 ... insulator.

Claims (10)

A heating element holding structure used in a substrate processing apparatus,
A heat insulating wall formed in a cylindrical shape;
A heating element having a cylindrical portion provided in a cylindrical shape along the inner peripheral side of the heat insulating wall, and a pair of power feeding portions provided so as to penetrate the heat insulating wall at the end of the cylindrical portion; ,
Together with at least a portion is provided between the pair of feeding parts, and the insulators other part is provided so as to reach the inside of the cylindrical portion beyond the upper inner circumferential surface of the cylindrical portion of the heating element,
A heating element holding structure. A heating element used in a substrate processing apparatus has a cylindrical cylindrical portion and a pair of power supply portions provided at ends of the cylindrical portion, and isolates the pair of power supply portions from each other. a insulating structures, to isolate between said pair of power supply portion extends from between the leading Symbol pair of power supply portions beyond the position on the circumferential surface of the cylindrical portion of the heating element to the inside of the cylindrical portion An insulating structure having a partition wall ;
A heating element holding structure . The pair of power feeding portions of the heating element are provided so as to penetrate a heat insulating wall formed on the outer peripheral side of the cylindrical portion, and are two insulating members separate from the heat insulating wall, The outer peripheral side insulating member provided on the outer periphery of the heat insulating wall and the inner peripheral side insulating member that reaches the inner side of the cylindrical portion beyond the inner peripheral surface of the cylindrical portion of the heating element. Retention structure . A pair of power feeding portions of the heating element is provided so as to penetrate a heat insulating wall formed on the outer peripheral side of the cylindrical portion, and is separated from the heat insulating wall and on the outer peripheral side of the heat insulating wall. The heating element holding structure according to claim 2, further comprising an outer peripheral insulating member provided . It said pair of power supply portions of the heating element, wherein provided so as to penetrate the heat insulating wall body formed on the outer peripheral side of the cylindrical portion, having said partition wall, said separately from the heat-insulating wall body The heating element holding structure according to claim 2 , further comprising an inner peripheral insulating member provided on the inner peripheral side of the heat insulating wall . Wherein the inner insulating member provided inside the heat insulating wall body, the retaining structure of the heating element according to claim 4 having an outer insulating member provided on the outside of the heat insulating wall body. The heating element holding structure according to claim 3, 4, 5, or 6 , wherein the insulating member has a hardness higher than that of the heat insulating wall . The heating element holding structure according to claim 3, 4 , 5, 6, or 7 , wherein the insulating member has higher bending strength than the heat insulating wall . The heating element holding structure according to any one of claims 2 to 8, wherein a pair of holding grooves for holding the pair of power feeding portions are provided . The heating element holding structure according to claim 9 , wherein the holding groove is formed to be cut out to reach an uppermost part or a lowermost part of the insulating structure .

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