JP3240180B2 - Heat treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus for minimizing a change in heating capacity in a vertical heat treatment furnace.

[0002]

2. Description of the Related Art For example, in the production of semiconductor wafers, oxidation, diffusion, annealing, CVD, etc. are performed.
Various heat treatment devices are used. For this type of heat treatment, use of a vertical heat treatment apparatus is becoming mainstream. The heat treatment furnace used for the vertical heat treatment apparatus has an upper end closed and an opening at a lower end, and an object to be processed such as a wafer is carried in / out from the lower end opening. During the processing in the heat treatment furnace, the lower end opening is airtightly closed by a lid. This lid is
When the object to be processed is carried in and out of the vertical heat treatment furnace, it is opened to secure a passage space larger than the maximum diameter of the member passing through the lower end opening.

[0003]

The passage space when the lid is opened allows a workpiece to be carried in and out, but also forms a path for releasing the heat in the vertical heat treatment furnace to the outside. . Therefore, each time the lid is opened, the heating capacity of the processing space changes, and it takes time to return to the process temperature again, and the throughput decreases. In addition, there is a problem in reducing the power of the apparatus.

[0004] Further, in comparison with a conventional type in which a heater is arranged around a vertical process tube, a type in which a planar heat source previously applied by the present applicant is arranged above the vertical process tube, The radiant heat from the planar heat source tends to go directly to the opening at the lower end of the tube, which not only wastes heat but also heats the member below the tube or the object to be processed. In the type using such a planar heat source, the object to be processed can be heated at a particularly high speed, but the heating speed is naturally limited due to the change in the heating capacity of the processing space described above.

It is an object of the present invention to provide a heat treatment apparatus which minimizes the change in the heating capacity of a processing space even when a workpiece is carried in and out, and has a high processing throughput.

[0006]

According to the present invention, there is provided a heat treatment apparatus for carrying in and out an object to be processed through a lower end opening of a vertical heat treatment furnace, wherein an airtight chamber is arranged below a lower end opening of the vertical heat treatment furnace; Opening and closing in a region opposed to the lower end opening,
The heat-shielding shutters are arranged at a plurality of different positions in the longitudinal axis direction, and at least one of the heat-shielding shutters is set to a closed state in a region opposed to the lower end opening when the object to be processed is carried in and out. , At least the uppermost
The heat shutter is a heating means for heating the shutter.
And a temperature sensor for detecting the temperature of the heating means.
To maintain the temperature gradient in the heat treatment furnace properly.
The temperature of the heating means is controlled .

[0007]

According to the present invention, at the time of loading / unloading of the object to be processed, any one of the plurality of stages of heat shielding shutters is closed in a region opposed to the lower end opening of the vertical heat treatment furnace. Since it is set, escape of heat quantity in the heat treatment furnace can be reduced. Also, install at least the top heat-shielding shutter.
The heating means and the temperature sensor
Temperature gradient in the heat treatment
In the course of treatment, contamination by heavy metals and the like can be prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment to which the present invention is applied will be described.
This will be specifically described with reference to the drawings. For example, as shown in FIG. 1, the apparatus according to the present embodiment mainly includes a heat treatment section 10 for performing various heat treatments on an object to be processed, such as a semiconductor wafer 28, an LCD, and the like. A shutter driving unit 30 for shutting off, a wafer loading / unloading unit 70 for loading / unloading the wafer 28 into / from the heat treatment apparatus while keeping the wafer 28 airtight from the outside, the wafer 28 and the planar heat source 18
And a wafer elevating unit 110 for rapid heating by relatively approaching to each other.

The heat treatment section 10 has, for example, the following configuration.

First, the process tube 12 is for heat-treating an object to be processed, such as an LCD or a wafer 28, in the tube, and is formed of a member having excellent heat insulating properties and low contamination, such as quartz. The process tube 12 has, for example, a double-tube structure having an inner tube 13.
An appropriate flow of the process gas introduced into the wafer 28 can be formed, and the film thickness of the film formed on the wafer 28 can be made uniform, the film quality can be improved, and the like.

In order to cover the process tube 12,
A heat insulating material 14 made of, for example, alumina ceramics is provided. The heat insulating material 14 is provided, for example, in FIG. 1 to provide an appropriate temperature gradient along the moving direction of the wafer 28.
It is preferable that the thickness be reduced toward the bottom as shown in FIG. Thereby, the heat insulating effect can be reduced toward the lower part.

Above the process tube 12, a planar heat source 18 is fixedly arranged on the inner wall above the heat insulating material 14. The planar heat source 18 is, for example, molybdenum disilicide (MoSi ₂ ), or iron (Fe) and chromium (C
r) and a resistance heating element such as a Kanthal (trade name) wire which is an alloy wire of aluminum (Al) and the like. For example, molybdenum disilicide can be used as a single wire, and Kanthal wire can be used as a coil. In particular, molybdenum disilicide is suitable as an oxide diffusion material because it can sufficiently withstand a high temperature of 1800 ° C. Planar heat source 18
Is formed by spirally arranging resistance heating wires made of, for example, a single wire of molybdenum disilicide.

The heating surface of the planar heat source 18 is preferably a circular shape similar to the processing surface of the wafer 28, and the outer diameter of the heating surface of the planar heat source 18 is smaller than the outer diameter of the wafer 28. Desirably, it is twice or more. Further, the heating surface of the planar heating source 18 is preferably arranged in parallel with the wafer 28, and the shape of the heating surface may be a uniform flat surface, or the peripheral portion may be formed on the wafer 28. It may be curved in the approaching direction.

The distance L shown in FIG. 1 is the shortest distance between the wafer 28 and the planar heat source 18, and determines the maximum value of the heating temperature of the wafer 28 as described later. Here, the shortest separation distance L is preferably short from the viewpoint of reducing the size of the apparatus, but is preferably long from the viewpoint of heating the entire surface of the large-diameter wafer 28 at a uniform temperature. Specifically, a distance that satisfies both conditions to some extent, for example, 300 to
It is about 600 mm.

Between the planar heat source 18 and the wafer 28,
It is desirable to arrange the heat equalizing member 16. This heat equalizing member 1
Numeral 6 is for controlling the radiant heat directed toward the wafer 28 in the vertical direction sufficiently by eliminating the uneven heat generation when the planar heat source 18 has uneven heat generation. Further, it is desirable that the heat equalizing member 16 be made of a material with low contamination, such as high-purity silicon carbide (SiC). This allows
The planar heat source 18 can be completely isolated from the processing space, and even when the planar heat source 18 is made of a material containing heavy metal that causes contamination, the contamination by the heavy metal can be effectively prevented. This is because it can be prevented.

The heat equalizing member 16 is disposed so as to face the processing surface of the wafer 28, and its outer diameter is preferably at least twice the outer diameter of the wafer 28, similarly to the surface heat source 18. The shape of the heat equalizing member 16 is desirably, for example, a shape in which the thickness of the central portion is thicker than the thickness of the peripheral portion, and a shape in which the peripheral portion is curved in a direction approaching the wafer 28. This is because, by adopting such a shape, for example, it is possible to reduce the thermal diffusion at the peripheral portion of the wafer 28, and it is possible to further improve the uniformity of the temperature between the central portion and the peripheral portion.

Around the heat insulating material 14, an inner shell 20 and an outer shell 24 formed of a double structure, for example, made of stainless steel or the like are arranged. A water cooling mechanism 22 is disposed between the inner shell 20 and the outer shell 24, so that the inside and outside of the heat treatment unit 10 can be thermally isolated. Thereby, when the high-temperature heat treatment is performed in the heat treatment unit 10, it is possible to sufficiently secure the safety of the external operation.

A manifold 60 made of, for example, quartz or metal is disposed below the process tube 12, and a flange 64 is provided at an upper end thereof. It is desirable that the flange 64 and the process tube 12 formed of quartz or the like be air-tightly fixed by an air-tight member such as an O-ring 62. Also, in order to perform, for example, evacuation and N ₂ purging in the process tube 12, and to introduce and exhaust a process gas into the process tube 12, the first manifold is provided in the manifold 60.
The gas introduction hole 26 and the first gas exhaust hole 27 of FIG.
It is provided at the position shown in FIG. In this case, the first gas exhaust hole 27 is formed, for example, to exhaust the process gas from the space enclosed between the process tube 12 and the inner tube 13, the heat insulating material 14, the inner shell 20, and the outer shell 24. Are provided so as to communicate with each other. Accordingly, it is possible to form an appropriate flow of the process gas introduced into the process tube 12, and it is possible to make the thin film formed on the wafer 28 uniform. The inner surface of the metal manifold 60 that comes into contact with the process gas is covered with, for example, quartz to prevent heavy metal contamination. Also, the metal manifold 60
A chilled water pipe 66 for circulating a coolant, for example, chilled water, is disposed on the outer wall of the chilled water pipe to cool the metal manifold 60.

The shutter driving section 30 is configured as follows, for example.

In this embodiment, the lower end opening 10 of the heat treatment section 10 is
A plurality of stages, for example, two stages of heat shielding shutters 32 and 36 are provided below a in a plurality of locations different in the vertical axis direction. Each of the shutters 32 and 36 has a pair of shutter plates 32 that are horizontally driven in different directions, for example, linearly driven.
a, 32b and 36a, 36b.

Each shutter plate 32a, 32b, 36a,
36b has a heat shielding function for minimizing and keeping a change in the heating capacity in the process tube 12, and is preferably formed of a heat insulating member. In this case, at least a pair of shutter plates 32a and 32 constituting the upper shutter, that is, the first heat shielding shutter 32.
It is preferable that b has a structure having a temperature control function (not shown), for example, a structure in which quartz wool is filled around a heater or the like and this is molded with a heat insulating member such as quartz. With such a structure, the temperature gradient between the planar heating source 18 and the shutter having the temperature control function can be made appropriate during the heat treatment, and furthermore, the contamination by heavy metals or the like can be made during the heat treatment. It is because it can prevent. In this case, for example, the temperature of the heater is fed back by a sensor or the like, for example, 3
By controlling the temperature to about 00 ° C to 800 ° C,
The temperature gradient can be appropriately maintained. A pair of shutter plates 36 constituting the lower second heat shielding shutter 36
It is preferable that a and 36b have a structure having a cooling function (not shown), for example, a structure in which quartz wool is filled around a water cooling jacket or the like and this is molded with a heat insulating member such as quartz. Thus, the space below the second heat-insulating shutter 36 can be set to a low temperature region such as room temperature. In this case, a cooling means such as ammonia, sulfur disulfide, water, or the like can be used as the cooling means, and it is desirable to cool to a temperature of, for example, 100 ° C. to 400 ° C. using the latent heat of the refrigerant.

As shown in FIG. 2A, a pair of shutter plates 32a and 32b constituting the first heat-shielding shutter 32 have, for example, a semicircular notch 39 at their leading ends.
Are formed. And a pair of shutter plates 32a,
32b can realize three types of states as shown in FIGS. FIG. 2A shows an open state. Further, as shown in FIG. 2 (B), a closed state can be realized by overdriving the pair of shutter plates 32a and 32b beyond the center position. In this case, in an overdriven state, it is desirable that the upper shutter plate 32a and the lower shutter plate 32b be as close to each other as possible. Also, the shutter plates 32a and 32
In the closed state shown in FIG. 2C in which both ends of 2b are slightly overdriven from the center position, a circular space through which the elevating shaft 116 can be freely inserted is formed by the two notches 39. Is done. Note that the second heat-insulating shutter 36 also includes the pair of shutter plates 32a, 3
It has a pair of shutter plates 36a and 36b that are exactly the same as the configuration of 2b.

Shutter plates 32a, 32b, 36a, 3
6b is connected and fixed to the cylinder rod 42. The cylinder rod 42 is freely driven in the horizontal direction by a driving mechanism (not shown), for example, an air cylinder.
Thereby, the opening and closing of the first heat shielding shutter 32 and the second heat shielding shutter 36 can be controlled. A bellows 40 is hermetically provided between the cylinder rod 42 and the flange 43 to keep the inside of the apparatus airtight against outside air when the shutter is opened and closed. In this case, the structure of the bellows 40 is desirably a double structure having an outer tube and an inner tube as described later. Further, it is desirable that the space between the outer tube and the inner tube be filled with an inert cooling gas to improve the durability, corrosion resistance and safety of the bellows.

For example, a second gas introduction hole 44 is provided in an intermediate portion between the shutter mechanism constituted by the shutter plate 32b and the shutter mechanism constituted by the shutter plate 36b. Further, for example, a second gas exhaust hole 4 is provided at an intermediate portion between the shutter mechanism constituted by the shutter plate 32a and the shutter mechanism constituted by the shutter plate 36a.
6 are provided. The second gas introduction hole 44 and the second gas exhaust hole 46 mainly include the first heat shielding shutter 32,
For example, both of the second heat shielding shutter 36 and FIG.
When the state is used to perform the evacuation and N ₂ purge, etc. shutter between the space 48 is a space between these upper and lower shutters.

The wafer loading / unloading section 70 has, for example, the following configuration.

The wafer loading / unloading section 70 mainly transfers the wafer 28 while keeping the airtight state to the atmosphere.
A first load lock chamber 80 and a second load lock chamber 90 for transferring the wafer 28 into and out of the process tube 12 are provided.

The first load lock chamber 80 has first and second load lock chambers.
Gate valves 82 and 83, a transfer arm 84, a third gas introduction hole 86, and a third gas exhaust hole 88. The second load lock chamber 90 includes third and fourth gate valves 92 and 93, a transfer arm 94, and a fourth gas introduction hole 9.
6, a fourth gas exhaust hole 98. Gate valve 8
2, 83, 92, and 93 are the outside of the apparatus and the load lock chamber 8.
0, 90 or load lock chambers 80, 9
It has an opening / closing function that opens when the wafer 28 is loaded and unloaded between the transfer chamber 100 and the transfer chamber 100 and closes when the airtight state is maintained. The transfer arms 84 and 94 are constituted by, for example, arms having articulated joints, and are connected to the load lock chambers 80 and 90 from the outside of the apparatus.
It has a function of loading and unloading wafers 28 from 90 to the delivery chamber 100. The third and fourth gas introduction holes 86 and 96 are for performing, for example, N ₂ purging of the load lock chambers 80 and 90, and the third and fourth gas exhaust holes 88 and 98 are for load lock chambers 80 and 90. For evacuation, for example.

The delivery chamber 100 is provided for transferring wafers 28 into the process tube 12, for example, N ₂
A fifth gas introduction hole 102 for purging, for example, a fifth gas exhaust hole 104 for evacuating is provided.

The wafer elevating unit 110 has, for example, the following configuration.

The wafer elevating unit 110 carries the wafer 28 into and out of the process tube 12 by vertically moving an elevating arm 114 to which an elevating shaft 116 is connected and fixed by an elevating mechanism 112. This is for relative movement with respect to the heat source 18, thereby enabling high-speed heat treatment of the wafer 28.

As shown in FIG. 1, a wafer holder 118 is provided on the elevating shaft 116 so that the wafer 28 can be held. Elevating shaft 116, wafer holder 118
Is preferably made of a material having excellent heat resistance and low contamination, such as quartz and high-purity silicon carbide. In particular, high-purity silicon carbide has better heat resistance than quartz and can sufficiently withstand a high temperature of about 1200 ° C., and is therefore suitable as a material used for such a heat treatment apparatus.

It is desirable that, for example, as shown in FIG. 1, three to four holding projections 119 are integrally formed on the peripheral portion of the wafer holder 118. This is because these holding projections 119 come into contact with the back surface of the wafer 28 so that the wafer 28 can be stably held.

The elevating shaft 116 is desirably connected to, for example, a rotating mechanism (not shown) provided on the elevating arm 114, and is preferably rotatable by the rotating mechanism. By this rotation, the wafer 28 held by the elevating shaft 116 is
The radiant heat from the planar heat source 18 and the first gas introduction unit 2
This is because a uniform heat treatment can be performed by the process gas from No. 6.

The elevating arm 114 and the elevating shaft 116 integrated therewith can be moved up and down at a high speed by the elevating mechanism 112, so that the wafer 28 can be heat-treated at a high speed. In this case, in this embodiment, in order to make the inside of the process tube 12 airtight against the outside air at the time of this vertical movement, a bellows having a double pipe structure constituted by an outer pipe 120 and an inner pipe 122 It is airtightly provided between the delivery room 100 and the lower part. Inner tube 1
Preferably, 22 is made of a material having excellent heat resistance, durability, stain resistance, corrosion resistance, and seal resistance, such as silicon carbide and Teflon. The outer tube 120 is preferably made of a material having excellent durability and heat resistance, such as stainless steel. The outer tube 120 mainly serves as a protective tube in the case where the inner tube 122 is broken before being replaced after a long use of, for example, one to two years.

It is desirable that the gap 121 between the outer tube 120 and the inner tube 122 can be filled with an inert gas such as nitrogen or argon. In this case, the filling gas is made inert so that even if this gas enters the apparatus, it does not adversely affect the heat treatment or the like. Here, the sixth gas introduction hole 124 and the sixth gas exhaust hole 126 are for filling these gases. It is preferable to provide, for example, a gas sensor (not shown) in order to detect the pressure in the gap 121.
The gas sensor may be a sensor that directly detects the pressure, or may be a sensor that detects a gas leak such as a processing gas. For example, a PPM sensor or the like may be used.

It is desirable that the pressure P1 in the apparatus and the pressure P2 in the gap 121 are controlled synchronously, for example, as follows. That is, when the wafer 28 is carried in and out, for example, P1 ≦ P2 <atmospheric pressure is established, so that when a pinhole is formed in the inner pipe 122 of the bellows, it is possible to prevent the leakage of the process gas in the apparatus. Further, at the time of heat treatment of the wafer 28, for example, P1> P2, so that when a pinhole is generated in the inner pipe 122 of the bellows, there is no possibility that the gas in the gap 121 will enter the apparatus, and the processing of the wafer 28 It is possible to prevent adverse effects.

Next, the operation when heat treatment is performed using this embodiment will be described.

First, the wafer 28 is carried to the wafer loading / unloading section 70.
Is entered. In this case, the second load lock chamber 90 is used.
The case in which the wafer is carried in is described below. Carry wafer 28
First, the inside of the load lock chamber 90 is introduced into the fourth gas guide.
N through inlet 96_TwoLarge beforehand by purging
It is desirable that the pressure be equal to the atmospheric pressure. Outside air and load
If the pressure inside the lock chamber is the same, the third gate valve
When 92 is opened, dust,
This is because scattering such as dust can be prevented. Next
3, the gate valve 92 is opened, and the wafer 28 is transferred to the transfer arm.
It is carried into the load lock chamber 90 by 94. afterwards
The third gate valve 92 closes and the fourth gas exhaust hole 98
Evacuates the load lock chamber,
N through the gas introduction holes 96 of FIG._TwoPurge is performed. this
In this case, the delivery chamber 100 mainly includes the fifth gas exhaust hole 104,
The fifth gas introduction hole 102 evacuates in advance,
N _TwoIt is desirable to purge. And said
When the fourth gate valve 93 opens, dust and dust
Pressure in the second load lock chamber 90 so that
Adjust so that the force and the pressure in the delivery chamber 100 are the same
Will be done. In this case, the process tube 1
2. The pressure in the space 48 between the shutters is also gas
Vacuum is drawn by the exhaust holes 27 and 46 and the gas introduction holes 26 and 44.
Kishi, N_TwoPurge to the same pressure as the load lock chamber.
It is desirable to keep.

Next, the fourth gate valve 93 is opened, and the wafer 28 is transferred to the transfer chamber 100 by the transfer arm 94. At this time, the wafer holder 118 is previously arranged in the transfer chamber 100 by the elevating mechanism 112, and the transferred wafer 28 is arranged in accordance with the holding projection 119 provided on the wafer holder 118. In this case, the pair of shutter plates 32a and 32b and the pair of shutter plates 36a and 36b are both in the state of FIG. 2B, and the inside of the process tube 12 and the delivery chamber 100 are as shown in FIG. Is in a state of being thermally shut off. .

Next, as shown in FIG. 4, the pair of shutter plates 36a and 36b are opened so as to be in the state shown in FIG. In this state, for example, the shutter plates 32a, 32b are heated by heaters built in the shutter plates 32a, 32b.
It is desirable to adjust the temperature of b.

Next, the wafer 28 is raised by the elevating shaft 116, and the wafer 28 is arranged in the inter-shutter space 48. Thereafter, as shown in FIG.
a and 36b are closed so as to be in the state of FIG.

Next, as shown in FIG. 6, the pair of shutter plates 32a and 32b are opened so as to be in the state shown in FIG. Then, as shown in FIG. 7, the wafer 28 is lifted by the lifting shaft 116, and then a pair of shutter plates 32a,
2b is closed so as to be in the state shown in FIG.

As described above, according to the present embodiment, at the time of loading a wafer, at least one of the upper first heat shielding shutter 32 and the lower second heat shielding shutter 36 is closed. In this state, heat can be shut off, and the wafer 28 can be loaded while the heating capacity of the process tube 12 is kept constant.

Thereafter, the wafer 28 is transferred to the process tube 1.
2 and heat treatment is started. Here, in this embodiment, the heat treatment of the wafer 28 is performed by rapidly bringing the wafer 28 close to the planar heat source 18 by the lifting mechanism 112. According to such a heat treatment method, since the radiant heat from the planar heat source 18 is directed substantially perpendicular to the processing surface of the wafer 28, the outer diameter of the wafer 28 is large, for example, 12 inches. Can also be heated at a uniform temperature over the entire processing surface of the wafer 28. Also,
Since the heating speed of the wafer 28 can be controlled by the approach speed, a rapid heat treatment at an arbitrary heating speed can be performed by increasing the approach speed.

As a result, in this embodiment, first, a high-speed heat treatment is enabled to perform a doping process of 50 to 100 angstroms, to form an extremely thin film such as a gate oxide film and a capacitor insulating film, and to form a shallow PN junction of 0.1 μm or less. Excellent effect in various heat treatments such as formation of
In spite of such rapid heating, the heat distribution in the plane of the wafer 28 can be made uniform, so that the slip, distortion, No warpage occurs. In addition, despite having such excellent performance, the bellows, which is constituted by the outer pipe 120 and the inner pipe 122, which are usually considered to be the most drastically changed with time, has a structure that is hardly contaminated by the process gas. Thus, a heat treatment apparatus with high durability that can withstand long-term use can be realized.

The approach speed of the wafer 28 to the planar heat source 18 is such that the temperature rise on the processing surface of the wafer 28 is, for example, 20
It is desirable that the speed be at least 100 ° C./Sec, particularly 100 ° C./Sec. The specific approach speed is preferably, for example, 50 to 200 mm / Sec or more.
In the present embodiment, a plurality of heat treatments having different temperatures can be performed by changing the set value of the shortest distance L between the wafer 28 and the planar heat source 18. Thus, for example, high-temperature treatment at a temperature of about 1200 ° C. or temperature of 500 ° C.
Low-temperature processing can be performed by selecting the processing at a low temperature, and a composite processing can be performed. Here, the “shortest separation distance” refers to a distance from a predetermined position to the planar heat source 18 when the process is performed while the approach of the wafer 28 is stopped and the wafer 28 is stopped.

It should be noted that the wafer 28 is moved from below to the planar heat source 1.
In order to increase the heating temperature of the wafer 28 by approaching the wafer 8, the wafer 28 is arranged at a position slightly above, for example, about 10 mm above the position of the shortest separation distance L, and the heating temperature of the wafer 28 is reduced to a desired temperature. After stabilization, it is desirable to place the wafer 28 at the position of the shortest separation distance L and perform processing. By doing so, it is possible to increase the throughput of processing, which is one of the technical problems of the single wafer heat treatment apparatus.

Next, after the heat treatment of the wafer 28 is completed, the wafer 28 is returned to the transfer chamber 100 by performing the reverse procedure of the above-described method. Thus, the wafer 28
Is returned, the upper first heat shielding shutter 32,
Alternatively, since at least one of the lower second heat shielding shutters 36 is in a closed state, heat can be shut off and the wafer 28 can be loaded while the heating capacity of the process tube 12 is kept constant. Becomes Finally, the wafer 28 is unloaded from the transfer chamber 100 to the outside of the apparatus.
Next, for example, the wafer 28 previously placed in the first load lock chamber 80 is loaded into the transfer chamber 100, and the wafer 28 is loaded into the process tube 12 by the same procedure as described above, and heat treatment is performed.

In the present embodiment, a plurality of, for example, two load lock chambers are provided because, for example, the first load lock chamber 80 is provided.
The reason is that the wafer is loaded into the second load lock chamber 90 in advance by the above-described method during the heat treatment of the further loaded wafer in the process tube 12, thereby increasing the processing throughput.

As described above, in this embodiment, the wafer 2
Also at the time of loading / unloading 8, the space between the process tube 12 and the delivery chamber 100 can be made a complete heat shielding structure.
Therefore, the heat capacity in the process tube 12 can be minimized and kept constant at all times. Thus, for example, once a certain appropriate temperature gradient is formed in the process tube 12, even if the wafer 28 to be processed is replaced, the time required to restore the formed temperature gradient and the required energy are minimized. It becomes possible. Thereby, for example, it is possible to increase the throughput of the process, which is a major technical problem of the single-wafer heat treatment furnace, and it is possible to lower the power of the apparatus and thereby reduce the manufacturing cost.

FIG. 8 shows a modified embodiment of the present invention.

In this modified embodiment, the wafer 28 is heated in advance and then loaded into the delivery chamber 100,
Further, it is another object of the present invention to improve the throughput of the apparatus by cooling the wafer 28 and carrying it out of the apparatus from the delivery chamber 100. For this reason, in this modification, a heating chamber 130 and a cooling chamber 140 are newly provided in the above-described embodiment. In this case, for example, the heating chamber 130 is connected to the first load lock chamber 80 by the fifth gate valve 13.
The cooling chamber 140 is desirably connected to the second load lock chamber 90 via a sixth gate valve 142, for example.

Here, the heating stage 1 is provided in the heating chamber 130.
34 are provided. The heating stage 134 has a function of preheating the wafer 28 to, for example, preferably 300 ° C. to 400 ° C. before carrying the wafer 28 to the transfer chamber 100, and preferably uses, for example, a halogen lamp or the like. It is desirable to heat by a method of heating by lamp heating or a method using a hot plate. In this case, when heating is performed using a hot plate, for example, a heating method in which the wafer 28 is brought into surface contact with the hot plate, and a proximity method in which the wafer 28 is heated in a state in which the wafer 28 is in point contact with the hot plate Can be used.
It is desirable that the hot plate has a structure covered with, for example, quartz or the like in order to prevent contamination by heavy metals or the like.

In the cooling chamber 140, a cooling stage 144 is provided. This cooling stage 144
Before the wafer is carried out of the apparatus, the wafer 28 is preferably cooled, for example, in a range of 300 ° C. from room temperature in advance. If the wafer 28 is cooled before being carried out of the apparatus as described above, it is possible to prevent an unnecessary oxide film or the like from being formed on the wafer 28 due to natural oxidation when being carried out of the apparatus. As such a cooling method, it is desirable to perform cooling using, for example, a method using a cooling gas, a method using a cooling jacket using a refrigerant, or a method using a cold plate.
Here, as the refrigerant, for example, ammonia, sulfur disulfide,
Water or the like can be used, and cooling can be performed using the latent heat of the refrigerant. In the case of heating using a cold plate, for example, a method of cooling by bringing the wafer 28 into surface contact with the cold plate,
And a proximity method in which the substrate is cooled while being in point contact with a cold plate.

Next, the operation of this modified embodiment will be described.

First, as shown by the arrow, the first
The wafer 28 is carried into the load lock chamber 80 of FIG. The operation in this case is the same as the loading method of the above-described embodiment. Next, a gas exhaust hole (not shown) is formed in the heating chamber 130,
After evacuating through the gas inlet and purging with N ₂ , the pressure becomes equal to that of the first load lock chamber 80,
The gate valve 132 of the heating chamber 1
30 is carried in as shown by the arrow.

Thereafter, the fifth gate valve 132 is closed, and the wafer 28 is
Heat to 400C to 400C. Next, the fifth gate valve 13
2, the wafer 28 is carried out to the first load lock chamber 80 as shown by the arrow. In this case, the wafer that has already been subjected to the heat treatment in the heat treatment unit 10 previously is carried out to the second load lock chamber 90.

Next, the wafer 28 is unloaded into the delivery chamber 100 via the second gate valve 83 as shown by the arrow,
The wafer 28 is placed on the wafer holder 118. Thereafter, various heat treatments of the wafer 28 are performed by the above-described method.
In this case, since the wafer 28 is heated to 100 ° C. to 400 ° C. in advance, the throughput of the heat treatment by the planar heat source 18 can be greatly improved.

When the heat treatment is completed, the wafer 28 is carried out to the cooling chamber 140 through the gate valves 93 and 142 as shown in FIG. In cooling room 140, cooling stage 1
Using 44, for example, it is cooled to a range from 300 ° C. to normal temperature. Thereafter, the wafer 28 is carried out of the apparatus through the gate valves 142 and 92 as shown by arrows. in this case. Since the wafer 28 has already been cooled, it is possible to prevent the formation of an unnecessary oxide film or the like due to the outside of the apparatus and exposure to the atmosphere.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

For example, in this embodiment, the process tube 1
2 is a double structure, whereby the process gas is introduced. However, the present invention is not limited to such a structure. For example, the process gas introduction hole is formed in a nozzle shape, and the lower portion of the process tube 12 is formed. Alternatively, a structure in which a process gas is introduced from the side surface and the process gas flows through the wafer 28 may be employed. Further, for example, a structure may be employed in which a process gas introduction hole is provided at, for example, a central portion of an upper portion of the process tube 12. With such a structure, the flow of the process gas is completely downflowed with respect to the wafer 28, so that excellent effects such as uniform film thickness and improvement of film quality are exhibited.

The shutter plates 36a and 36b constituting the second heat shielding shutter 36 are not limited to those whose surfaces are made of quartz or the like, but may be made of stainless steel, for example.

The object to be processed by the apparatus according to the present invention may be at least a planar object to be processed, and may be an LCD or the like other than the semiconductor wafer. The heat treatment to which the present invention is applied is CVD.
Of course, the present invention can be applied to, for example, oxidation, diffusion, annealing, and the like.

[0064]

As described above, according to the present invention, at the time of loading / unloading an object to / from a vertical heat treatment furnace, at least one heat-shielding shutter is used to provide a region facing the lower end opening of the furnace. Is closed, the change in the heating capacity of the processing space can be minimized. Also, less
And the heating means and temperature provided on the top heat-shielding shutter
Temperature sensor to adjust the temperature gradient in the heat treatment furnace.
It can be made positive, and furthermore,
Contamination can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view for explaining an apparatus to which the present invention is applied.

FIG. 2 is a schematic explanatory diagram for explaining a shape and an open / closed state of a shutter in the apparatus of FIG.

FIG. 3 is a schematic operation explanatory view showing a state where a wafer is carried into a delivery chamber by the apparatus of FIG. 1;

FIG. 4 is a schematic operation explanatory view showing a state in which a lower shutter is opened from the state of FIG. 3;

FIG. 5 is a schematic operation explanatory view showing a state in which a wafer is carried into a space between shutters from the state of FIG. 4 and a lower shutter is closed.

FIG. 6 is a schematic operation explanatory view showing a state in which an upper shutter is opened from the state of FIG. 5;

FIG. 7 is a schematic operation explanatory view showing a state where a wafer is carried into the process tube from the state of FIG. 6 and an upper shutter is closed.

FIG. 8 is a schematic explanatory diagram for describing a modified embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heat treatment part 12 Process tube 13 Inner tube 14 Heat insulation member 16 Heat equalizing member 18 Planar heat source 26 1st gas introduction hole 27 1st gas exhaust hole 28 Wafer 30 Shutter drive part 32 1st heat shielding shutter 32a Shutter plate 32b Shutter plate 36 Second heat-shielding shutter 36a Shutter plate 36b Shutter plate 48 Space between shutters 60 Manifold 70 Wafer carry-in section 80 First load lock chamber 90 Second load lock chamber 100 Delivery chamber 110 Wafer elevating section 116 elevating shaft 118 wafer holder 120 outer tube 121 gap 122 inner tube

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/22 511 H01L 21/205 H01L 21/31 H01L 21/324

Claims (4)

(57) [Claims] 1. A heat treatment apparatus for loading and unloading an object to be processed from a lower end opening of a vertical heat treatment furnace, wherein an airtight chamber is arranged below a lower end opening of the vertical heat treatment furnace;
And, opening and closing in a region opposed to the lower end opening, heat shielding shutters are arranged at a plurality of different locations in the longitudinal axis direction, at least one of the heat shielding shutters when loading and unloading the object, the set in the closed state at the lower end opening facing the region, at least the uppermost of said heat shield shutter is the Shah
A heater for heating the heater and a temperature of the heater.
And a temperature sensor that emits,
The temperature of the heating means is controlled so that the temperature gradient is maintained appropriately
By heat treatment apparatus according to claim Rukoto. 2. The heat-shielding shutter according to claim 1, further comprising: a support portion for mounting and supporting the object to be processed, and a shaft portion connected to the support portion and driving the support portion to move up and down. Is a heat treatment apparatus comprising a pair of shutter plates horizontally driven in mutually different directions, and a notch portion through which the shaft portion can be inserted at the opposite ends of the pair of shutter plates. 3. The heat shielding shutter according to claim 2, wherein, when the support portion is located above the support portion, the opposed ends of the pair of shutter plates are brought close to each other so that the two cut-out portions are formed in the two cutout portions. It is set to the closed state where the shaft is inserted,
When the support portion is located below the pair of shutter plates, the pair of shutter plates is overdriven to a position beyond the center line of the lower end opening, and the pair of shutter plates are set in a closed state in which the tip ends overlap. Characteristic heat treatment equipment. 4. The heating switch according to claim 1, wherein the heating chamber is connected to the airtight chamber via a gate valve.
A heating chamber with a stage, and a gate valve in the hermetic chamber.
And a cooling chamber provided with a cooling stage.
Thermal processing apparatus characterized by having a et.