JP3711291B2 - Heat treatment equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a heat treatment apparatus for heat-treating an object to be processed in a vertical process tube.
[0002]
[Prior art]
For example, in the manufacture of semiconductor wafers, LCD substrates, and the like, various heat treatment apparatuses are used to perform processes such as oxidation, diffusion, annealing, and CVD. In these heat treatment apparatuses, for example, achieving high process accuracy, improving the uniformity of the temperature distribution in the surface of the object to be processed, and increasing the efficiency of heat treatment are major technical issues. Yes.
[0003]
By the way, in recent years, the semiconductor process has been further miniaturized, and along with this, the diameter of the wafer has been increased to 8 inches to 12 inches, and a large substrate such as an LCD substrate has been uniformly and efficiently produced. A heat treatment apparatus for processing is also required. Process miniaturization progresses in response to this situation, processing becomes more precise as workpieces become larger in diameter, more uniform temperature distribution in the surface of the workpiece, heat treatment efficiency Further improvement is required. In addition, there is a demand for improvement in throughput when manufacturing an object to be processed having such a large diameter.
[0004]
[Problems to be solved by the invention]
With the increase in the diameter of the object to be processed, there are the following problems when actual processing is performed.
[0005]
That is, it is necessary to effectively prevent slip and distortion generated in the object to be processed as the diameter of the object is increased, and to improve the uniformity of the temperature distribution in the surface of the object. Therefore, in order to meet such demands, how to uniformly apply temperature to the object to be processed, and the temperature difference between the central part and the peripheral part, which is caused by the amount of heat radiation in the peripheral part is larger than that in the central part. How to reduce the amount of technology is a major technical issue. Further, along with the miniaturization of the process, it is necessary to increase the accuracy of processing on the object to be processed and reduce the degree of contamination on the object to be processed. Therefore, how to efficiently perform heat treatment in a short time in order to achieve uniform film quality and film thickness within the surface of the object to be processed is a major technical issue.
[0006]
Accordingly, an object of the present invention is to provide a heat treatment apparatus capable of efficiently performing heat treatment while ensuring in-plane uniformity on the object to be processed in view of the problems in the conventional heat treatment apparatus.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is a vertical process tube having a lower end opening for loading and unloading the object to be processed, and provided with a primary heating source on the upper side for radiatively heating the object to be processed disposed at the processing position;
The object to be processed in a horizontally supported state is carried into the process tube from the opening, and a holder for the object to be processed that can be moved up and down to be set at the processing position;
Gas supply means for supplying a reaction gas toward a processing position in the process tube;
A secondary heating source that radiates a secondary radiant heat ray toward the back surface of the target object set at the processing position and heats at least a peripheral portion of the target object by being heated by the primary heating source. When,
It is characterized by having.
[0008]
The invention according to claim 2 is the invention according to claim 1,
The secondary heating source is horizontally disposed in a region below the processing position and not interfering with the lifting path of the holder.
[0009]
The invention according to claim 3 is a vertical process tube having a lower end opening for loading and unloading the object to be processed, and provided with a heat source for heating the object to be processed arranged at the processing position,
The object to be processed in a horizontally supported state is carried into the process tube from the opening, and a holder for the object to be processed that can be moved up and down to be set at the processing position;
Gas supply means for supplying a reaction gas toward a processing position in the process tube;
Reflection that directly or indirectly enters radiant heat rays from the heat source, reflects the incident heat rays toward the back surface of the target object set at the processing position, and heats at least the peripheral portion of the target object. Members,
It is characterized by having.
[0010]
The invention according to claim 4 is the invention according to claim 3,
The reflecting member is horizontally attached to the workpiece holder at a position below the workpiece support position of the workpiece holder.
[0011]
The invention according to claim 5 is the invention according to claim 4,
The reflection member is supported so as to be movable up and down relative to the holder for the object to be processed, and the distance between the object and the object to be processed is variable.
[0012]
The invention according to claim 6 is the invention according to claim 4,
At least two reflection members are arranged at different positions in the vertical axis direction of the object holder, and each reflection plate is formed with regions having different heat ray reflectivities in the circumferential direction. By rotating, the relative positional relationship of the regions having different reflection efficiencies of the reflecting plates changes.
[0013]
[Action]
In the first and third aspects of the invention, in-plane uniformity of the processing temperature of the object to be processed can be ensured by heating the peripheral edge of the object to be processed that is particularly radiated from the back surface side of the object to be processed. it can. In the invention of claim 1, the peripheral edge of the object to be processed is heated by the secondary heating source that is heated by the primary heating source and radiates the secondary radiant heat. In the invention of claim 3, the direct heating from the planar heating source is performed. This is performed by reflecting the heat ray incident on the object or the indirect side from the back surface side to the peripheral edge of the object to be processed.
[0014]
According to the second aspect of the present invention, the secondary heating source is disposed horizontally below the object to be processed and at a position that does not interfere with the lifting path of the object to be processed, so that the heating of the secondary heating source and the object to be processed can be achieved. The peripheral edge can be efficiently heated.
[0015]
According to the fourth aspect of the present invention, the reflection member is horizontally attached to the workpiece holder at a position lower than the workpiece support position of the workpiece holder, thereby reflecting the heat rays to the peripheral edge of the workpiece. Can be performed efficiently. Moreover, even if the reflecting member moves to the processing object insertion / removal position together with the processing object holder, the temperature of the reflecting member does not increase so much, so that the temperature of the inlet / outlet atmosphere of the processing object does not rise.
[0016]
In the invention of claim 5, the intensity of heat rays reflected by the peripheral edge of the object to be processed can be varied by making the distance between the reflecting member and the object to be processed variable. Thereby, the in-plane uniformity of the processing temperature of a to-be-processed object can be adjusted.
[0017]
According to the invention of claim 6, when at least two reflectors rotate relatively, the relative positional relationship of the regions having different reflection efficiencies of the reflectors changes, and the heat rays reflected on the periphery of the object to be processed The intensity is variable.
[0018]
【Example】
The details of the present invention will be described below with reference to the embodiments shown in FIGS.
[0019]
FIG. 1 is a cross-sectional view showing an overall configuration of a heat treatment apparatus according to an embodiment of the present invention, and in particular, an example of a structure for heating both front and back surfaces of a workpiece W.
[0020]
The heat treatment apparatus in the present embodiment is provided with a heat treatment unit 10, an object carrying-in / out unit 50, and a shutter driving unit 60.
[0021]
The heat treatment unit 10 is a part for performing various heat treatments on the workpiece W such as a semiconductor wafer or an LCD, and includes a vertical process tube 12. The process tube 12 is a cylindrical member having a lower end opening. In the present embodiment, the process tube 12 is made of high-purity transparent quartz.
[0022]
An air supply pipe 14 for supplying process gas from the outside is arranged inside the process tube 12. This air supply pipe 14 has an opening at the upper end in the internal space of the process tube 12, and on the way to the opening, that is, below the heat treatment position of the workpiece W, as shown in FIG. A preheating portion 14A having a gas passage is formed. The preheating unit 14A absorbs the heat of the atmosphere below the heat treatment position of the workpiece W, thereby heating the process gas supplied from the outside and stored at once, and then ejects it into the space above the processing unit. It is like that. Therefore, since the process gas is set in a state close to the processing temperature until it is ejected, the time until the temperature reaches the temperature for the reaction processing is shortened.
[0023]
Further, the position corresponding to the back side of the processing surface of the object to be processed W is absorbed by the preheating unit 14A, so that the object to be processed W is disposed between the processing surface of the object to be processed W and its back space. Is set to a temperature at which a temperature gradient for setting the in-plane uniformity is obtained. In addition, as a structure in the preheating part 14A of this air supply pipe 14, you may provide the radiation fin (not shown) arranged in multiple numbers along the circumferential direction. Thereby, the heat from the heat treatment part 10 can be efficiently transmitted to the process gas.
[0024]
Further, as shown in FIG. 1, an exhaust pipe 26 for exhausting the process gas supplied from the air supply pipe 14 is provided in the vicinity of the lower end opening of the process tube 12. By combining these pipes, the process tube 12 is provided. An appropriate flow is generated in the process gas introduced into the inside of the processing object W so that the thin film formed on the surface of the workpiece W can be made uniform. Note that the air supply and exhaust pipes 14 and 28 that come into contact with the process gas are covered with, for example, quartz or the like, and measures against heavy metal contamination are taken.
[0025]
On the other hand, a heat insulating material 16 made of, for example, alumina ceramics is provided around the process tube 12. For example, the heat insulating material 16 is provided inside a heat insulating material 17 made of a ceramic wool molded product arranged on the outer periphery thereof.
[0026]
A water cooling mechanism 18 including a water cooling jacket formed of an inner shell 18A and an outer shell 18B is provided on the outer wall surface of the heat insulating material 17, and heat isolation is performed between the heat treatment unit 10 and the outside. Thereby, when high-temperature heat treatment is performed in the heat treatment section 10, it is possible to ensure the safety of external operation.
[0027]
Further, a planar heat source 20 as a primary heating source is provided above the process tube 12. This planar heat source 20 is, for example, resistance heat generation such as molybdenum disilicide (MoSi2) or Kanthal (trade name) wire which is an alloy wire of iron (Fe), chromium (Cr) and aluminum (Al). The body is arranged on the upper inner wall surface of the heat insulating material 16. Molybdenum disilicide can sufficiently withstand the high temperature of 1800 ° C. Such a planar heat source 20 can also be configured, for example, by arranging resistance heating wires made of a single wire of molybdenum disilicide in a spiral shape. Further, it is effective from the viewpoint of thermal efficiency that the heat generation surface of the planar heat source 20 is at least twice the outer diameter of the workpiece W.
[0028]
By the way, between the process tube 12 and the planar heat source 20, it is heated by the heat from the planar heat source 20 to uniformly radiate secondary radiant heat to the surface of the workpiece W. A soaking member 22 is arranged. For this heat equalizing member 22, for example, a material having a relatively low contamination degree such as silicon carbide (SiC) and having good heat resistance is selected. In the present embodiment, the heat equalizing member 22 is as shown in FIG. In addition, the heat treatment is provided so as to cover the upper side and the side of the workpiece W set at the processing position, and in a region below the processing position of the workpiece W in a horizontal state in parallel with the workpiece W. The member 22A is included. The heat equalizing member 22A can emit secondary radiant heat rays from the back side of the object to be processed W at least to the peripheral portion of the object to be processed W. Therefore, the peripheral portion of the object W to be processed with a relatively large amount of heat dissipation is heated by the secondary radiant heat from the heat equalizing member 22A located on the back surface, so that the increase in the amount of heat dissipation can be suppressed and the object to be processed. The temperature distribution in the plane of W is prevented from changing.
[0029]
As another example of the arrangement configuration of the above-described heat equalizing member 22, the heat equalizing member may be divided and arranged on the front surface side and the back surface side of the workpiece W as shown in FIG. In this case, in particular, in the case of the back surface, as in the case shown in FIG. 1, it is necessary to arrange in a state in which radiant heat can be applied to the peripheral portion of the workpiece W. The heat equalizing member 22A located on the back side is not limited to the member that radiates secondary radiant heat, and can be made of, for example, silicon carbide (SiC) having a mirror surface formed of a polishing layer on the surface. Accordingly, the radiant heat rays from the heat equalizing member 22 located on the front surface side directly reach the surface of the object to be processed W, and a part of the heat radiation member 22A located on the rear surface side is reflected by this mirror surface. It reaches the peripheral edge of the processing body W.
[0030]
Another example of such a divided arrangement is the structure shown in FIG. That is, the heat equalizing member 22 located on the surface side of the workpiece W is suspended from the upper end position to the range where the workpiece W is located. Therefore, in this case, heating at the peripheral edge of the workpiece W is promoted on both the front surface and the back surface, and a decrease in temperature due to heat radiation from the peripheral edge is prevented.
[0031]
Furthermore, the arrangement configuration of the heat equalizing member 22 located on the back side of the workpiece W includes the configuration shown in FIG. That is, in the arrangement configuration shown in FIG. 5, the heat equalizing members 22 are respectively arranged on both sides of the back surface of the object to be processed W in an area where the process tube 12 does not interfere with the lifting path of the object to be processed W. . In addition, since the soaking | uniform-heating member 22 arrange | positioned at the back surface is heated by the planar heat source 20 before carrying in the to-be-processed body W, it heats toward the peripheral part of the to-be-processed body W from a back surface side. It becomes possible. Alternatively, as shown in FIG. 6, a part of the heat equalizing member 22 can be integrated with the holder 30 to be processed. In this way, by heating the surface of the object to be processed W as well as the back surface, particularly the periphery of the object to be processed W, the temperature at the periphery of the object to be processed W is increased. The temperature distribution in the surface can be made uniform without being lowered. In addition, by using a material having good heat resistance such as silicon carbide and a low degree of contamination, the processing space of the process tube 12 can be thermally isolated from the heat generation source. Even if it is comprised by the material containing the heavy metal which becomes, the contamination by a heavy metal can be prevented effectively.
[0032]
On the other hand, inside the process tube 12, there is provided an object holder 30 for transferring the object W to the heat treatment part 10 with respect to the treatment part 10.
[0033]
The workpiece holder 30 is composed of, for example, a rod member that can move up and down between the processing position shown in FIG. 1 and the loading / unloading position of the workpiece W. A mounting portion 30A is formed. In the case of the present embodiment, as shown in FIG. 7, for example, the mounting portions 30 </ b> A are provided on the upper surface of the cradle 30 </ b> A <b> 1 formed in a ring shape along the circumferential direction, in four locations in the figure. A support column 30A2 is provided. The cradle 30A1 is set to a skeleton structure that does not hinder the radiant heat line from the heat equalizing member 22 or 22A located on the back side of the workpiece W.
[0034]
The shielding member 30B is provided for shielding the radiant heat from the inside of the processing section, sealing the process gas in the heat treatment section, and further rectifying the air flow when the body to be processed W moves. It is comprised with the cover body provided in the middle to the axial direction other end of the holder 30. FIG.
[0035]
And since the shielding member 30B will heat-store by the heating from the heat equalization member 22 located in the back surface of the to-be-processed object W, the function to preheat the to-be-processed object W mounted can be given. Further, the shielding member 30B has a configuration for performing the function of rectifying the airflow when the workpiece W is moved. That is, in FIG. 1, the outer diameter (A) of the shielding member 30B is between the inner wall surface of the preheating portion 14A of the air supply pipe 14 when the placement portion 30A moves from the processing position for loading and unloading. The gap is set so as to obtain a gap that does not cause a rapid flow rate in the existing gas. In this embodiment, the gap is smaller by about 5 mm to 30 mm than the inner diameter (B) of the inner wall surface of the preheating portion 14A. Is set.
[0036]
This is to prevent, for example, an in-plane temperature difference from occurring in the object W when the object holder 30 is moved from the heat treatment part 10 after the heat treatment. That is, when the approaching members relatively move as in the relationship between the preheating portion 14A and the shielding member 30B, the gas existing between them, particularly the gas existing near the periphery of the shielding member 30B is entrained. A flow rate due to. The velocity of the airflow is influenced by the size of the gap between the two, and if the gap is too small, the flow velocity increases rapidly, and convection occurs in the processing position, which is one space, with the shielding member 30B as a boundary. It will be. For this reason, the heat dissipation from the peripheral part of the to-be-processed object W will be accelerated | stimulated. Therefore, by determining the outer diameter of the shielding member 30B, the temperature gradient in the processing position is not changed during the heat treatment. In addition to this, when the workpiece W moves to the processing position because it is unloaded, an increase in the air velocity is suppressed to prevent an in-plane temperature difference of the workpiece W from occurring. . Therefore, when the workpiece W moves for loading and unloading, even if a certain speed is generated in the airflow around the shielding member 30B, this speed is not allowed to act on the processing position. So-called convection at the processing position can be prevented and an in-plane temperature difference of the workpiece W can be prevented from being generated.
[0037]
In this embodiment, in addition to specifying the outer diameter of the shielding member 30B, the shielding member 30B is formed with a plurality of gas escape holes 30B1 penetrating upward along the circumferential direction as shown in FIG. ing. By forming this gas escape hole 30B1, the entrainment of gas in the vicinity of the periphery of the workpiece W may be reduced.
[0038]
Note that the shape of the shielding member 30B is not limited to the above-described lid shape, and it is of course possible to set a shape that suppresses the turbulence of airflow and the generation of speed when the workpiece holder 30 moves. You may make it the shape which combined the cone shape up and down, and you may provide a plurality of sheets continuously.
[0039]
FIG. 8 shows an example in which a plurality of shielding members are provided. In this case, a plurality of shielding members are provided along the vertical axis direction, in FIG. 8, four stages of shielding members 30B10, 3012, 30B14, and 30B16 are provided, and the outer diameter is sequentially increased toward the lower stage. Is set. In addition, partition plates 30B20, 30B22, and 30B24 that are fixed to the inner wall of the process tube 12 and have a diameter reduced in order from the upper side along the vertical direction are disposed in the vicinity of the peripheral surface of each shielding member. The partition plates 30B20, 30B22, and 30B24 are provided to block the heat in the heat treatment unit 10 to prevent a temperature gradient between the heat treatment unit and the lower side, thereby preventing the generation of airflow. Further, a plurality of gas escape holes are formed in the shield members at each stage, similarly to the shield member 30B of FIG. In this case, the gas escape holes are formed at different positions between the shielding members at the respective stages. Similarly, a gas escape hole can be formed in each partition plate. Further, the second and subsequent shielding members 30B10, 3012, 30B14, and 30B16 for the partition plates are located below the partition plates 30B20, 30B22C, and 30B24 when the cradle 30A of the workpiece holder 30 is in the processing position. The positional relationship is set and fixed to the rod portion of the workpiece holder 30. Note that the structure of the shielding member shown in FIG. 8 is for the case where the process tube 12 does not have the preheating portion 14A of the intake pipe 14 shown in FIG. 1, but the intake pipe 14 is the same as in FIG. It is also possible to target the case where the remaining heat portion 14A is provided, and FIG. 9 shows the structure in this case. In the case shown in FIG. 9, the preheating portion 14 </ b> A of the intake pipe 14 is arranged on the lower side, and the diameter is sequentially reduced.
[0040]
In addition to the above-described shielding members 30B10, 30B12, 30B14, and 30B16, another one heat shielding member 30C is provided at the other axial end of the workpiece holder 30. The heat shield member 30C is constituted by a flange, and is connected to a cooling rod 32 located below the end. The heat shield member 30 </ b> C covers the vicinity of the lower end opening of the process tube 12 and will be described later when the placement portion 30 </ b> A of the workpiece holder 30 is set at the treatment position of the workpiece W in the heat treatment unit 10. This is to block the passage of radiant heat to the workpiece carrying-in / out unit 50. Of the above-described shielding members, the shielding member 30B10 located at the uppermost stage as shown in FIGS. 8 and 9 can be used for heating the back surface of the workpiece W, and further on the back surface side. It is also possible to change the temperature by changing the material or the like between the central portion and the peripheral portion of the soaking member. In particular, in the latter case, it is a matter of course that the temperature of the peripheral portion is set higher.
[0041]
On the other hand, the cooling rod 32 is for cooling the workpiece holder 30. For this reason, the cooling rod 32 is made of metal, and a water cooling jacket 32A is formed therein as shown in FIG.
[0042]
Further, as shown in FIG. 10, a through hole 34 reaching the mounting portion 30 </ b> A is formed in the central portion of the workpiece holder 30 and the cooling rod 32. A lead wire 36 </ b> A of a thermometer 36 for approximately measuring the processing temperature in the heat treatment unit 10 is inserted into the through hole 34. The thermometer 36 is arranged on the back surface of the mounting portion 30 </ b> A of the workpiece W so as to detect the surface temperature of the workpiece W. Further, the through hole 34 can be used as an optical path to an optical temperature sensor that detects the temperature from the surface color of the workpiece W, for example, instead of the thermometer. A part of the through hole 34 is connected to a supply pipe 38 for a purge gas such as N2 gas, for example, so that the inside of the through hole 34 is purged.
[0043]
In addition, it is necessary to reduce the contact area of the mounting portion 30 </ b> A in the workpiece holder 30 in order to prevent uneven temperature distribution due to heat radiation in the surface of the workpiece W. Therefore, in this embodiment, instead of the mounting column 30A2 of FIG. 7 provided in the mounting portion 30A, the mounting support structure shown in FIG. 11 can be used. That is, the structure shown in FIG. 11 (A) is formed with gradient surfaces 30A10 and 30A12 that intersect at substantially right angles, and the workpiece W is placed on the apex of one gradient surface 30A10, and the other gradient surface. 30A12 is used as a guide surface for centering. Further, the structure shown in FIG. 11B is formed by forming the cutting tool relief 30A20 at the intersecting position when forming the intersecting sloped surfaces shown in FIG. 11A. It is improving. Further, the structure shown in FIG. 11C uses the rod member 30A30 on which the intersecting surfaces are formed.
[0044]
On the other hand, in FIG. 1, the processing object carry-in / out unit 50 is constituted by an airtight chamber located below the lower end opening of the process tube 12, and mainly a processing object holder 30 while maintaining an airtight state with respect to the atmosphere. It is a location where the to-be-processed object W is carried in / out.
[0045]
For this reason, as shown in FIG. 12, the workpiece loading / unloading unit 50 transfers the first and second load lock chambers 52 and 54 and the workpiece W from the load lock chambers 52 and 54 to the process tube 12. The delivery chambers 56 for delivery to each other are arranged at right angles. The first and second load lock chambers 52 and 54 have the same configuration, and the first load lock chamber 52 will be described. First and second gate valves 52A and 52B, expansion and contraction / lifting and rotation A possible transfer arm 52C, a gas introduction hole 52D, and a gas discharge hole 52E are provided.
[0046]
The second load lock chamber 54 includes first and second gate valves 54A and 54B, a transfer arm 54C that can be extended, retracted, and rotated, a gas introduction hole 54D, and a gas discharge hole 54E. The gate valves 52A, 52B, 54A, 54B are opened when the workpiece W is carried in / out between the outside of the apparatus and the load lock chambers 52, 54 or between the load lock chambers 52, 54 and the delivery chamber 56. It has an open / close function that closes when maintaining an airtight state. The transfer arms 52C and 54C are configured by, for example, arms having multiple joints, and carry the workpiece W into and out of the load lock chambers 52 and 54 from the outside of the apparatus or from the load lock chambers 52 and 54 to the delivery chamber 56. It has a function. The gas introduction holes 52D and 54D are for purging the load lock chambers 52 and 54 with, for example, N2 gas, and the gas discharge holes 52E and 54E are for evacuating the load lock chambers 52 and 54, respectively. Is.
[0047]
In FIG. 1, a shutter drive unit 60 is provided in the vicinity of the object carrying-in / out unit 50.
[0048]
That is, the shutter driving unit 60 includes a first shutter 62 and a second shutter 64 for heat shielding, which are provided in a plurality along the vertical axis direction below the lower end opening of the process tube 12. The first and second shutters 62 and 64 for heat insulation are arranged on both sides of the workpiece carry-in / out section 50 in the vertical axis direction, and are moved in opposite directions by a driving member 66 such as a cylinder. The shutter plates 62A and 62B and 64A and 64B that can be opened and closed are provided.
[0049]
Each of the shutter plates has a heat insulating structure in which a water cooling jacket is formed. Among these shutter plates, the shutter plates 62A and 62B in the first shutter 62 located on the lower end opening side of the process tube 12 are configured so that the opposing surfaces are formed in an L shape and overlap as shown in FIG. Has been. This is to prevent the temperature below the hermetic chamber from rising by blocking the passage of radiant heat rays from the process tube 12 when the opposing surfaces are in close contact with each other. Of course, each shutter plate 62A, 62B has a hole through which the cooling rod 32 is inserted. In addition, as shown in FIG. 14A, the shutter plates 62A and 62B are provided with a recess at the tip end where the object holder 30 can be inserted. And this front-end | tip can be mutually overlapped as shown in FIG.14 (B), and the passage of the heat ray from upper direction is interrupted | blocked in the overlapped state. The second shutter 64 can also be configured in the same manner as in FIGS.
[0050]
The airtight chamber in which the first and second shutters 62 and 64 are located is provided with a structure for switching the atmospheric gas of the workpiece W.
[0051]
That is, as shown in FIG. 15, for example, an inert gas different from the process gas, for example, a helium gas, is provided at the positions equally divided in the circumferential direction at the advancing and retreating portions of the first and second shutters 62 and 64. An injection nozzle 70 for blowing (He) is disposed. This jet gas is an undesired product film in the course of movement of the object to be processed W by switching the atmosphere gas immediately from the atmosphere of the process gas to the object to be processed W carried out from the heat treatment section 10 and cutting off the contact of the process gas. Is prevented from forming. In addition, such an atmospheric gas is immediately switched and placed in contact with an inert gas that is not affected by the temperature from the heat treatment section, so that the thermal budget of the workpiece W, so-called treatment The heat balance received by the body W is stabilized to suppress the change of the temperature distribution in the surface, and the in-plane uniformity is ensured. And according to the number of the injection nozzles 70, exhaust ports (not shown) are provided at equal positions where they do not interfere with the injection nozzles 70 in the circumferential direction. This injection nozzle 70 has injection ports for injecting cooling gas in the horizontal direction at a plurality of locations in the vertical axis direction, and as shown in FIG. 15, the cooling gas is parallel to the surface of the workpiece W in the retracted position. Can be injected. Note that this jet gas may be used for cooling the first and second shutters, and further, the workpiece W carried out of the heat treatment unit 10 may be cooled using this gas.
[0052]
By the way, in FIG. 15, the drive mechanism 40 of the to-be-processed object holder 30 and the cooling rod 32 is configured as follows.
[0053]
That is, the drive mechanism 40 includes an elevating arm 42 connected to an axial end of a cooling rod integrated with the workpiece holder 30. The elevating arm 42 includes, for example, a ball screw and a nut. Can be moved up and down by a lifting mechanism 44 combined. In the elevating arm 42, for example, a rotation mechanism via a gear is provided, and this rotation mechanism is at least one or more rotations when the workpiece holder 30 is carried into and out of the heat treatment section 10. When the workpiece holder 30 is retracted from the heat treatment section 10 and the workpiece W is opposed to the spray nozzle 70 positioned below the first shutter 62, the rotation is, for example, about 60 rpm. Is supposed to be performed. In order to secure airtightness when the workpiece holder 30 is moved up and down, a seal structure 46 using a magnetic fluid is provided between the hermetic chamber and the workpiece holder 30 (see FIG. 1). Alternatively, a bellows structure (not shown) is provided. In addition, regarding the raising / lowering drive of the to-be-processed object holder 30, you may make it move up and down independently from the raising / lowering mechanism 44 mentioned above.
[0054]
The object 30 is rotated at a necessary number of rotations during the heat treatment, but is moved while rotating at least one rotation at the time of carrying in and out of the heat treatment unit 10. The drive control is performed. Such rotation during loading and unloading ensures uniform in-plane uniformity of the workpiece W before and after heat treatment by uniformizing the supply of radiant heat from the planar heat source 24 and the contact with the process gas. To be executed.
[0055]
Next, the operation will be described.
[0056]
When the heat treatment of the workpiece W is performed, the workpiece W is carried into the workpiece carry-in / out section 50. That is, this case will be described below with the second load lock chamber 54 as an object.
[0057]
First, when the workpiece W is carried in, the inside of the second load lock chamber 54 is set to the same pressure as the atmospheric pressure in advance by purging N2 through the gas introduction hole 54D. If the outside air and the load lock chamber 54 have the same pressure, when the gate valve 54B is opened, it is possible to prevent intrusion and scattering of dust and dirt due to a rapid flow of gas. Next, the gate valve 54 </ b> B is opened and the workpiece W is carried into the delivery chamber 56. Thereafter, the gate valve 54B is closed, and evacuation is performed by the gas exhaust hole 54E. In this case, it is desirable that the delivery chamber 56 is similarly evacuated and purged with N2 in advance. Furthermore, it is desirable that the space between the process tube 12 and the first and second shutters 62 and 64 is also evacuated to have the same pressure as the load lock chamber 54.
[0058]
On the other hand, when the object to be processed W is transferred to the delivery chamber 56 via the gate valve 54A by the transfer arm 54C in the load lock chamber 54, the placement portion 30A of the holder 30 for the object to be processed is previously transferred to the transfer arm 54C. Therefore, the object to be processed W is delivered. At this time, the first shutter 62 is closed and the second shutter 64 is opened. When the delivery of the workpiece W is completed, the workpiece holder 30 starts to rotate by the drive mechanism 40. For example, the workpiece holder 30 rotates one or more times such as 2 to 3 rotations until reaching the predetermined processing position of the heat treatment unit 10 and reaches the predetermined processing position. Stop rotation. At this time, both the first and second shutters 62 and 64 are open.
[0059]
As the workpiece holder 30 moves up, the workpiece W is placed in an atmosphere of process gas as soon as it moves from the atmosphere of helium gas in the gas switching structure to the heat treatment section 10. The workpiece holder 30 that has reached the processing position is positioned at a position close to the vicinity of the inner peripheral surface of the preheating portion 14A of the air supply pipe 14, and is switched to the number of rotations during the heat treatment. In the heat treatment unit 10, the preheated process gas is supplied from the air supply pipe 14.
[0060]
When the heat treatment is started by supplying the process gas, the first shutter 62 remains open, and the second shutter 64 is kept closed. Accordingly, since the shielding member 30B of the workpiece holder 30 is disposed so as to cover the lower part of the heat treatment unit 10, the heat rays of radiant heat leaking from the heat treatment unit 10 are blocked. In addition, in the heat treatment unit 10, the process gas is sealed to set the heat treatment environment, and the surface and the back surface of the workpiece W via the heat equalizing member 22, particularly in the case of the back surface, with respect to the peripheral portion. Since radiant heat rays can be applied, the uniformization of the temperature distribution in the surface of the workpiece W is promoted.
[0061]
On the other hand, at the end of the heat treatment, the object holder 30 is positioned below the first shutter 62 with the placement portion 30A. At this time, the shielding member 30B of the holder 30 for the object to be processed is processed by reducing gas entrainment at the peripheral edge by setting the outer diameter dimension of the gas escape hole and the preheating portion 14A of the air supply pipe 14. Heat dissipation from the peripheral edge of the body W can be suppressed, and uneven temperature distribution in the surface can be prevented.
[0062]
In addition, the workpiece holder 30 positioned below the first shutter 62 rotates while the workpiece W on the mounting portion 30A is switched to a rotation speed of, for example, about 60 rpm. The helium gas supplied from the advancing / retreating section cuts off heat from the workpiece W loading / unloading section 50, switches the ambient gas environment, and further cools the workpiece W. At this time, the object to be processed W is promoted to be cooled by the cold air from the first shutter 62 located above.
[0063]
Thus, the to-be-processed object W by which the cooling after heat processing was performed is set the same state as the time of carrying in. Then, in this state, the workpiece W is moved from the position facing the injection nozzle 70 to the delivery chamber 56, and the workpiece W can be carried out by a procedure reverse to that during loading.
[0064]
According to this embodiment, since the shutter provided in the hermetic chamber located below the lower end opening of the process chamber can be used as the cooling structure of the object to be processed, the cooling time can be reduced without requiring a special structure. It can be shortened.
[0065]
Furthermore, according to the present embodiment, by providing a heat insulating material that surrounds the lower part of the processing position between the heat equalizing member and the process tube, the temperature gradient between the front surface and the rear surface of the object to be processed in the heat treatment position is increased. It is possible to optimize the temperature, and it is possible to prevent the generation of an air flow due to a sudden change in the temperature gradient and suppress the heat radiation at the peripheral edge of the object to be processed.
[0066]
Note that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist of the present invention.
[0067]
For example, the object to be processed according to the present invention may be an object to be processed having at least a planar shape, and may be an LCD or the like other than a semiconductor wafer. Furthermore, as a heat treatment apparatus to which the present invention is applied, other than a CVD apparatus, for example, an apparatus applied to oxidation, diffusion, and annealing can be targeted.
[0068]
Next, an embodiment for effectively heating the back surface of the object to be processed in the heat treatment apparatus according to the present invention will be described with reference to FIG.
[0069]
The embodiment shown in FIG. 16 and subsequent figures is characterized in that a reflecting member having a pair structure is provided on the same axis as the workpiece holder 30 in place of the above-described shielding member. In FIG. 16 and subsequent figures, the same components as those used up to FIG. 15 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0070]
In other words, the first reflecting member 100 and the second reflecting member 110 are provided below the placement portion 30 </ b> A in the object holder 30 so as to be coaxial with the object holder 30.
[0071]
The first reflecting member 100 is supported so as to be able to rotate and move up and down independently with respect to the workpiece holder 30, and the second reflecting member 110 may be fixed to the holder 30. Preferably, it can be moved up and down integrally with the first reflecting member 100. In the above configuration, only the first reflecting member 100 is rotatable, but it is sufficient that the first and second reflecting members 100 and 110 are relatively rotated.
[0072]
The first and second reflecting members 100 and 110 are provided by removing the shielding member 30B in the embodiment shown in FIG. 1, and the surface facing the mounting portion 30A is mirror-finished by polishing, for example. Silicon carbide (SiC) is used.
[0073]
On the board surfaces of the first and second reflecting members 100 and 110, regions having different reflection efficiencies along the circumferential direction are equally divided into a plurality of locations. The regions with different reflection efficiencies can be obtained by changing the transmittance of radiant heat rays. For this reason, in this embodiment, as in the example shown in FIG. 17, the first reflecting member 100 side is provided with a transmissive portion 100A that is equally divided along the circumferential direction. On the reflecting member 110 side, a heat ray absorbing portion 110A matching the shape of the transmitting portion 100A is formed in the reflecting surface. Moreover, as a structure which makes such a transmittance | permeability different, it can obtain also by providing a transparent part and an opaque part alternately. In this case, transparent quartz is selected as the transmission portion, and the transmittance is varied by making the transparent quartz opaque along the circumferential direction of the transparent quartz. In the case where the opaque portion is configured, gray carbide silicon carbide (SiC) may be distributed. When silicon carbide (SiC) is used, the radiant heat can be absorbed without being reflected, so that the radiant heat can be emitted as secondary energy from this portion.
[0074]
The first and second reflecting members 100 and 110 having such a structure in which the transmittance of heat rays is different cause the phase of the transmission portion of the heat rays to differ by the relative rotation of the two, so-called overlapping. By adjusting the condition, the amount of reflected heat to the workpiece W can be adjusted.
[0075]
That is, in FIG. 17, as indicated by a two-dot chain line, the second reflection is obtained by changing the overlapping state of the transmission part 100A on the first reflection member 100 side with respect to the heat ray absorption part 110A of the second reflection member. The amount of reflected heat from the member 110 changes.
[0076]
In the present embodiment, in order to adjust such an overlapping state, a temperature sensor (not shown) for detecting the temperature of at least the peripheral portion of the workpiece W and the vicinity of the center is arranged, and detection from this temperature sensor is performed. The amount of reflected heat to the workpiece W can be changed by adjusting the overlap between the transmission part 100A and the heat ray absorption part 110A according to the temperature.
[0077]
In addition, among the first and second reflecting members 100 and 110, the upper surface of the first reflecting member 100 at the position facing the back surface of the workpiece W is centered in the cross-sectional shape as shown in FIG. It can also be formed in a concave shape in which the part is thinner than the peripheral part. In this case, the concave angle θ is set to an angle at which the heat rays reflected toward the back surface of the workpiece W can travel.
[0078]
Further, as shown in FIGS. 16 and 18, a cavity 100B is formed inside the first reflecting member 100, and either the heating medium or the cooling medium is formed in the cavity 100B. Has been introduced.
[0079]
As a structure for supplying a medium to the inside of the first reflecting member 100, a second reflecting member 110 is used as shown in FIG. That is, inside the second reflecting member 110, a circulation path 110B communicating with the cavity 100B of the first reflecting member 100 is formed inside the shielding member 30C, and a medium is externally provided in a part of the circulation path 110B. 110C, 110D, and 110E that can supply and collect the water are respectively piped. Thereby, the medium filled in the circulation path 110B circulates in the cavity 100B of the first reflecting member 100 and is discharged via the circulation path 110B. In FIG. 16, black circles indicate the seal member at the connecting portion.
[0080]
With respect to the heating medium or the cooling medium supply timing, with respect to the heating medium, the mounting portion of the processing object holder 30 is placed on the preheating unit 140 described later in the process of moving the processing object holder 30 toward the processing position. This is the time when 30A is located, and the cooling medium is the time when the workpiece holder 30 starts moving toward the workpiece loading / unloading section 50. Thereby, when heated, the preheating effect can be improved, and when cooled, the workpiece W can be carried in and out at a temperature close to room temperature. In addition, the workpiece W that is moved for unloading is set to a processing temperature or lower when leaving the processing position, so there is no possibility that an unnecessary natural oxide film or the like is formed.
[0081]
On the other hand, in FIG. 19, a preheating unit 140 including a space for preheating the workpiece W is provided at a position below the opening of the process tube 12 and at an upper position of the first and second load lock chambers 52 and 54. It has been. The preheating unit 140 is set to have a length in the vertical direction that allows the placement unit 30 </ b> A of the workpiece holder 30 and the first and second reflecting members 100 and 110 to be positioned. Thereby, the object holder 30 on which the object W is placed in the object carry-in / out part 50 can move to the preheating part 140 when the first shutter 62 is opened. Then, when the workpiece holder 30 moves to the preheating unit 140, the first shutter 62 is closed, the workpiece holder 30 is temporarily stopped, and the surface temperature is increased by receiving the radiant heat from the heat equalizing member 22. Raru. As this temperature, the temperature of 400 degreeC or more and 600 degrees C or less which is the temperature from which the absorption efficiency of the infrared rays which make a heat ray becomes favorable is set. Thus, the object to be processed is preheated while moving from the object to be processed loading / unloading section 50 toward the processing position, and when the temperature reaches the processing position, the temperature does not increase rapidly. It is possible to suppress adverse effects such as. Moreover, the time until the temperature rises to the processing temperature when the processing position is reached can be shortened.
[0082]
Next, the operation of this embodiment will be described.
[0083]
When the heat treatment of the workpiece W is performed, the workpiece W is carried into the workpiece carry-in / out section 50. That is, this case will be described below with the second load lock chamber 54 as an object.
[0084]
First, when the workpiece W is carried in, the same pressure as the atmospheric pressure is set in advance by purging the inside of the second load lock chamber 54 with N2 through the gas introduction hole 54D (see FIG. 12). If the outside air and the load lock chamber 54 have the same pressure, when the gate valve 54B is opened, it is possible to prevent intrusion and scattering of dust and dirt due to a rapid flow of gas. Next, the gate valve 54B is opened, and the workpiece W is carried into the second load lock chamber 54. Thereafter, the gate valve 54B is closed, and evacuation is performed by the gas exhaust hole 54E. In this case, it is desirable that the delivery chamber 56 is also evacuated in advance. Furthermore, it is desirable that the space between the process tube 12 and the first and second shutters 62 and 64 is evacuated to the same pressure as the load lock chamber 54.
[0085]
On the other hand, when the workpiece W is transferred to the delivery chamber 56 via the gate valve 54A by the transfer arm 54C in the load lock chamber 54, the placement portion 30A of the holder 30 for the workpiece is previously transferred to the transfer arm 54C. Since the workpiece W is positioned on the transfer path (position indicated by reference numeral S1 in FIG. 19), the workpiece W is delivered. At this time, the first shutter 62 and the second shutter 64 are closed. When the delivery of the workpiece W is completed, the workpiece holder 30 starts to rotate by the drive mechanism 40. For example, the workpiece holder 30 rotates one or more times such as 2 to 3 rotations until reaching the predetermined processing position of the heat treatment unit 10 and reaches the predetermined processing position. Stop rotation. The first and second shutters 62 and 64 are closed immediately after the holder 30 or the like moves upward and reaches a position where it does not interfere with each shutter.
[0086]
As the workpiece holder 30 moves up, the workpiece holder 30 that has moved above the workpiece loading / unloading section 50 temporarily stops when it reaches the preheating section 140, as indicated by S1 in FIG. To do. And if this state is maintained, while a heating medium will be supplied in the cavity part 100B of the 1st reflection member 100, the temperature of the to-be-processed object W will rise by the radiant heat from the soaking | uniform-heating member 22, and what is called Preheating is performed. The preheating temperature is detected by the thermometer 36.
[0087]
And when the to-be-processed object holder 30 raises to a process position when the temperature of the to-be-processed object W in the preheating part 140 reaches predetermined temperature, it has approached the soaking | uniform-heating member 22, and the surface of the to-be-processed object W is approached. The temperature rises by receiving radiant heat. Moreover, the back surface of the to-be-processed object W is heated with the reflected light from the reflective surface of a 1st reflective member.
[0088]
At this time, when the in-plane temperature of the workpiece W is not uniform based on the temperature detected by a temperature sensor (not shown), the reflection part 100A in the first reflecting member 100 and the reflection in the second reflecting member 110 are reflected. The relative position with the opaque portion 110A forming the surface is changed.
[0089]
Furthermore, regarding this temperature adjustment, not only the above-described change in reflection efficiency, but also by changing the distance between the first reflecting member 100 and the mounting portion 30A independently of the object holder 30. The temperature adjustment can be executed while ensuring the in-plane uniformity of the workpiece W.
[0090]
Moreover, the temperature rise of the back surface of a to-be-processed object can be accelerated | stimulated also by the surface shape of a 1st reflective member.
[0091]
On the other hand, when the film forming process at the processing position is completed, the workpiece holder 30 is lowered. Before reaching the workpiece loading / unloading section 50 during the lowering, the cooling medium is replaced with the heating medium in the cavity 100B of the first reflecting member 100, and the temperature of the first reflecting member 100 is lowered. When the temperature of the object to be processed W held by the object holder 30 reaches near room temperature as the temperature of the first reflecting member 100 is lowered by the cooling medium, it is denoted by reference numeral S1 in FIG. As described above, the placement portion 30A of the workpiece holder 30 is located in the workpiece carry-in / out portion 50, and the above-described delivery operation is performed. Thereafter, when the object to be processed W is transferred again to the mounting portion 30A of the object holder 30, the same procedure as described above is repeated.
[0092]
【The invention's effect】
In the first and third aspects of the invention, in-plane uniformity of the processing temperature of the object to be processed can be ensured by heating the peripheral edge of the object to be processed that is particularly radiated from the back surface side of the object to be processed. it can.
[0093]
According to the second aspect of the present invention, it is possible to efficiently heat the secondary heat source, and thus the peripheral edge of the object to be processed.
[0094]
In invention of Claim 4, reflection of a heat ray to a to-be-processed object peripheral part can be performed efficiently. Moreover, even if the reflecting member moves to the processing object insertion / removal position together with the processing object holder, the temperature of the reflecting member does not increase so much, so that the temperature of the inlet / outlet atmosphere of the processing object does not rise.
[0095]
According to the fifth and sixth aspects of the present invention, the in-plane uniformity of the processing temperature of the object to be processed can be adjusted by changing the intensity of heat rays reflected on the peripheral edge of the object to be processed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view for explaining an overall configuration of a heat treatment apparatus showing an embodiment of the present invention.
2 is a perspective view showing a structure of an air supply pipe used in the heat treatment apparatus shown in FIG. 1. FIG.
3 is a partial cross-sectional view showing another example of a heating structure in the heat treatment apparatus shown in FIG.
4 is a cross-sectional view showing another example of a heating structure used in the heat treatment apparatus shown in FIG.
FIG. 5 is a cross-sectional view showing still another example of a heating structure used in the heat treatment apparatus shown in FIG.
6 is a cross-sectional view showing still another example of a heating structure used in the heat treatment apparatus shown in FIG. 1. FIG.
7 is a partial perspective view showing an example of a holder for an object to be used used in the heat treatment apparatus shown in FIG. 1. FIG.
8 is a partial cross-sectional view showing another structure of the workpiece holder shown in FIG. 7. FIG.
9 is a cross-sectional view showing another example of the workpiece holder shown in FIG. 7. FIG.
10 is a cross-sectional view for explaining the internal structure of the workpiece holder shown in FIG. 7. FIG.
11A to 11C are partial cross-sectional views showing the structure of the mounting portion of the workpiece holder shown in FIG.
12 is a schematic plan view for explaining the configuration of an object loading / unloading unit used in the heat treatment apparatus shown in FIG. 1. FIG.
13 is a sectional view of a shutter used in the heat treatment apparatus shown in FIG.
14A and 14B are schematic diagrams illustrating an example of the shutter illustrated in FIG. 13, in which FIG. 14A illustrates an opened state and FIG. 14B illustrates a closed state.
15 is a cross-sectional view showing a gas switching and cooling structure in the heat treatment apparatus shown in FIG. 1. FIG.
FIG. 16 is a cross-sectional view for explaining another embodiment of the heat treatment apparatus according to the present invention.
FIG. 17 is a perspective view for explaining a part structure of a heat treatment apparatus according to the present invention.
FIG. 18 is a partial enlarged cross-sectional view for explaining the structure of a reflecting member used in the heat treatment apparatus according to the present invention.
FIG. 19 is a cross-sectional view for explaining the overall configuration of another embodiment of the heat treatment apparatus according to the present invention.
[Explanation of symbols]
10 Processing position
12 Process tube
14 Air supply pipe
14A Preheating part
30 Holder for workpiece
30A placement section
30B shielding member
30B10-30B16 shielding member
30C Heat shield member
50 Object loading / unloading section
60 Shutter drive
62 First shutter
64 Second shutter
66 Injection nozzle
100 first reflecting member
100A transparent part
100B Cavity for circulating heat medium
110 Second reflecting member
110A opaque part

Claims (4)

Has a lower end opening for loading and unloading of the specimen, the primary heating source for radiant heating the object to be processed placed in the processing position, and a vertical process tube that is provided only above the processing position,
The object to be processed in a horizontally supported state is carried into the process tube from the opening, and a holder for the object to be processed that can be moved up and down to be set at the processing position;
Gas supply means for supplying a reaction gas toward a processing position in the process tube;
A secondary heating source that radiates a secondary radiant heat ray toward the back surface of the target object set at the processing position and heats at least a peripheral portion of the target object by being heated by the primary heating source. When,
Have
The secondary heating source has a lower end opening for loading and unloading an object to be processed, is formed so as to surround the process tube, and horizontally toward the process tube in a region below the processing position. heat treatment apparatus characterized by have a protruding portion. A vertical process tube having a lower end opening for loading and unloading the object to be processed and having a heat source for heating the object to be processed disposed at the processing position , only above the processing position ;
The object to be processed in a horizontally supported state is carried into the process tube from the opening, and a holder for the object to be processed that can be moved up and down to be set at the processing position;
Gas supply means for supplying a reaction gas toward a processing position in the process tube;
Reflection that directly or indirectly enters radiant heat rays from the heat source, reflects the incident heat rays toward the back surface of the target object set at the processing position, and heats at least the peripheral portion of the target object. Members,
Have
The reflection member has a lower end opening for loading and unloading the object to be processed, is formed so as to surround the process tube, and projects horizontally toward the process tube in a region below the processing position. The heat processing apparatus characterized by having a part . In claim 2 ,
The heat treatment apparatus, wherein the reflection member is supported so as to be movable up and down with respect to the holder for the object to be processed, and a distance between the object and the object to be processed is variable. In claim 2 ,
At least two reflection members are arranged at different positions in the vertical axis direction of the object holder, and each reflection plate is formed with regions having different heat ray reflectivities in the circumferential direction. A heat treatment apparatus characterized in that, by rotating, the relative positional relationship between regions having different reflection efficiencies of the reflecting plates changes.

Images