JP2003121079A - Heat treating device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treating device capable of improving temperature rise speed without causing warp and slip of a workpiece. SOLUTION: This heat treating device is provided with a treating unit 24 performing a prescribed heat treatment to the work piece W. The treating unit is provided with a treating vessel 26 formed of an optical transparent member, a support member 36 supporting the workpiece, upper part heating means 70 provided outside a ceiling part of the treating vessel, lower part heating means 72 provided outside the bottom of the treating vessel, a gas introducing means 50 introducing treating gas into the treating vessel, and exhaust means 40 exhausting atmosphere in the treating vessel. The workpiece is heated from the both sides so as to improve the temperature rise speed without causing the warp and the slip of the workpiece.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-wafer type heat treatment apparatus and a heat treatment method for performing a predetermined heat treatment on a semiconductor wafer or the like.

[0002]

2. Description of the Related Art Generally, in order to manufacture a semiconductor integrated circuit, various heat treatments such as a film forming process, an etching process, an oxidation process and a diffusion process are performed on a semiconductor wafer such as a silicon substrate. In this case, from the viewpoint of improving throughput, it is necessary to quickly raise and lower the temperature of the semiconductor wafer within a range that does not adversely affect the semiconductor wafer. Here, a conventional general heat treatment apparatus will be described. FIG. 8 is a schematic configuration diagram showing a conventional single-wafer heat treatment apparatus. As shown in FIG. 8, this heat treatment apparatus has a processing container 2 which is made of, for example, aluminum and has a cylindrical shape, and an exhaust port 4 is provided at the bottom of the processing container 2 so that the inside of the processing container 2. Can be evacuated. A susceptor 8 having a heater 6 is provided in the processing container 2, and the semiconductor wafer W is mounted on the upper surface of the susceptor 8. A shower head portion 12 having a large number of gas ejection ports 10 is attached to a ceiling plate 14 at the ceiling of the processing container 2 so as to introduce a processing gas such as a film forming gas into the processing container 2. It has become.

[0003]

By the way, as described above, from the viewpoint of improving the production efficiency of product wafers, that is, the throughput, the temperature raising / lowering operation of the wafer W, especially the temperature raising operation, must be performed quickly. However,
As described above, when the wafer W is heated from the back surface side by the heater 6 built in the susceptor 8, the rate of temperature rise is not so high and the throughput is limited. In this case, increase the capacity of the heater 6 and increase the capacity of the heater 6.
Although it is possible to increase the input power to the wafer, if the input power is too large, a large temperature difference occurs between the front surface and the back surface of the wafer having a thickness of about 0.5 to 1 mm, and thermal expansion cannot be ignored. A difference occurs, which causes the wafer itself to warp or cause a slip such as a crack, which limits the amount of power input.

Further, for example, when the process temperature is about 800 ° C., when the wafer temperature is raised from about room temperature to this process temperature, the temperature difference between the central portion and the peripheral portion of the wafer is about 40 ° C. There is also a problem that the temperature raising operation is performed in the generated state, and as a result, the thermal history greatly differs between the central portion of the wafer and the peripheral portion. Also,
Although there is a heat treatment apparatus using a heating lamp as a heating means, the current situation is that the above-mentioned problems have not been basically solved. The present invention has been made to pay attention to the above problems and to solve them effectively. An object of the present invention is to provide a heat treatment apparatus and a heat treatment method capable of improving the temperature rising rate without causing warping or slippage of the object to be treated.

According to a first aspect of the present invention, in a heat treatment apparatus having a treatment unit for subjecting an object to be treated to a predetermined heat treatment, the treatment unit includes a treatment container formed of a light transmissive member, and the treatment object. A support member for supporting the processing body, an upper heating means provided outside the ceiling of the processing container, a lower heating means provided outside the bottom of the processing container, and a processing gas introduced into the processing container. A heat treatment apparatus comprising a gas introducing unit and an exhaust unit for exhausting the atmosphere in the processing container. According to this, since the object to be processed is heated from both sides by the upper heating means and the lower heating means, the temperature rising rate can be improved without causing warping or slips in the object to be processed, and the throughput can be improved. Not only can it be improved, but it is also possible to prevent a large temperature difference between the central portion and the peripheral portion of the object to be treated when the temperature is raised.

In this case, for example, as defined in claim 2, the upper heating means and the lower heating means each have a carbon wire heater. Further, for example, as defined in claim 3, the support member has a column made of a light transmissive member. Further, for example, as defined in claim 4, the heating means has a gas nozzle made of a light transmissive member.

Further, for example, as defined in claim 5,
The evacuation means has a suction head made of a light transmissive member having a large-diameter atmosphere suction port. Further, for example, as defined in claim 6, the light transmissive member is quartz. Further, for example, as defined in claim 7, the processing unit is integrally covered with an outer casing made of metal. Further, for example, as defined in claim 8, a plurality of sets of the processing units are assembled and the whole is covered with an outer casing made of metal. The invention defined in claim 9 defines a method invention performed by using the above-mentioned apparatus invention, that is, an object to be processed is provided in a processing container capable of supplying a predetermined gas and exhausting an internal atmosphere. In a heat treatment method for accommodating and subjecting the object to be processed to a predetermined heat treatment, an upper heating means provided above the object to be processed and a lower part below the object to be processed with respect to the object to be processed. It is a heat treatment method characterized in that the object to be treated is heated to a predetermined temperature by simultaneously radiating heat rays from both the lower heating means provided. In this case, for example, as defined in claim 10, the processing container is formed of a light-transmissive material, and the upper heating means and the lower heating means are respectively installed outside the processing container. The heat rays pass through the processing container and are applied to the object to be processed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a heat treatment apparatus and a heat treatment method according to the present invention will be described in detail below with reference to the accompanying drawings. 1 is a configuration diagram showing a heat treatment apparatus of the present invention, FIG. 2 is a plan view showing an arrangement state of columns of a supporting member, FIG. 3 is an enlarged sectional view showing a suction head of an exhaust unit, and FIG. 4 is a gas nozzle of a gas introducing unit. FIG. 5 is a plan view showing the arrangement state of FIG. As shown in FIG. 1, the heat treatment apparatus 20 is wholly covered with an outer housing 22 made of metal such as stainless steel. A processing unit 24 that performs heat treatment is housed.

The processing unit 24 has a processing container 26 made of, for example, quartz as a light transmitting material. As described above, the processing container 26 is formed into a cylindrical shape by using, for example, quartz, and a discharge inlet 28 protruding in the lateral direction is provided on a part of the side wall of the treatment container 26.
Extends through the outer casing 22 and extends outward.
Such a processing container 26 made of quartz can be easily formed by, for example, fusing a quartz block formed by dividing the upper and lower portions into two by thermal melting. A gate valve 30 that is opened and closed when the wafer W is carried in and out is provided at the discharge inlet 28.
A load lock chamber 32, which can be evacuated, is connected here via. A transfer chamber may be connected instead of the load lock chamber 32. Then, in the load lock chamber 32, the turning direction (θ direction) and the bending (X direction)
A transfer arm 34 composed of an articulated arm mechanism that is movable in the Y direction) and in the vertical direction (Z direction) is provided, and the wafer W can be transferred into the processing container 26.

A support member 36 for supporting the semiconductor wafer W is provided on the bottom portion 26A of the processing container 26.
Specifically, as shown in FIG. 2, the support member 36 includes three columns 36 made of a light-transmissive member such as quartz.
The three columns 36A are arranged in a circle at intervals of about 120 degrees and are provided upright from the container bottom 26A. Note that only two columns 36A are shown in FIG. A notched step portion 38, which is notched like a step, is formed at the upper end of each strut 36A. The notched step portion 3
The peripheral portion of the wafer W can be placed on the wafer 8 to support it.

The processing container 26 is provided with exhaust means 40 for exhausting the atmosphere in the processing container 26. Specifically, the exhaust unit 40 has an intake head 42 installed on the bottom 26A of the container on the inner side surrounded by the three columns 36A. As shown in FIG. 3, the suction head 42 is formed of a light-transmissive member such as quartz, and has a large-diameter atmosphere suction port 44 that is expanded upward in an inverted conical shape. Thus, the atmospheric gas can be sucked substantially uniformly from the outer peripheral side of the wafer W. A suction pipe 45 made of a light transmissive member such as quartz is connected to the base of the suction head 42, and the suction pipe 45 penetrates the side wall of the processing container 26. Further, the suction pipe 45 is connected to an exhaust pipe 46 penetrating the outer casing 22, and a vacuum pump 48 is interposed in the exhaust pipe 46 so as to evacuate the inside of the processing container 26. Has become. A seal member 49 such as an O-ring is interposed in a portion of the exhaust pipe 46 that penetrates the outer casing 22.

Further, the processing container 26 is provided with gas introducing means 50 for introducing the processing gas into the inside thereof. Specifically, as shown in FIG. 4, the gas introducing means 50 has two circular ring-shaped gas nozzles 52 and 54 which are made of a light transmitting member such as quartz and have different diameters. A large number of gas outlets 52A and 54A are provided on the lower surfaces of the gas nozzles 52 and 54 along the circumferential direction thereof so that each processing gas can be ejected toward the processing space S substantially uniformly. And each of the gas nozzles 5
Reference numerals 2 and 54 are respectively connected to introduction tubes 56 and 58 made of a light-transmissive member such as quartz, and the introduction tubes 56 and 58 penetrate the side wall of the processing container 26. Further, each of the introduction pipes 56, 58 is connected to each of the gas pipes 60, 62 provided so as to penetrate the outer casing 22, and the flow rate of a necessary processing gas is controlled by a flow rate controller such as a mass flow controller (not shown). Can be supplied while doing so.

A seal member 6 such as an O-ring is provided at a penetrating portion of each of the gas pipes 60 and 62 with respect to the processing container 26.
4, 66 are interposed. Although two ring-shaped gas nozzles 52 and 54 are provided here, the number and shape thereof are not particularly limited. Then, as a structural feature of the present invention, outside the ceiling portion 26B of the processing container 26,
In the illustrated example, the upper heating means 70 is provided on the upper surface, and the lower heating means 72 is provided on the outside of the bottom portion 26A of the processing container 26, and on the lower surface in the illustrated example. Here, the upper heating means 70 and the lower heating means 72 have exactly the same configuration.

As shown in FIG. 5, the upper heating means 7 is also provided.
0 and the lower heating means 72 have, for example, spirally formed carbon wire heaters 74 and 76, and these carbon wire heaters 74 and 76 are block bodies each made of a light-transmissive member such as quartz. It is embedded in 78 and 80. Then, each carbon wire heater 74,
Controlled power can be supplied to 76 via leads 82 and 84, respectively. Each lead wire 8
Insulating materials 86 and 88 such as quartz are interposed in the penetrating portions of the outer housing 22 and the outer housing 22. The processing unit 24 thus formed is housed in the outer housing 22 with a heat insulating layer 90 having a predetermined gap. The heat insulating layer 90 is a vacuum heat insulating layer in which the gap is in a vacuum state here, but the heat insulating layer 90 is not limited to this. For example, alumina (Al ₂ O ₃ ) or the like is used as the heat insulating layer 90.
You may make it fill as. In FIG. 1, reference numeral 92 is a seal member such as an O-ring.

Next, the operation of this embodiment configured as described above will be described. First, the transfer arm 34 in the load lock chamber 32 maintained in a vacuum state is driven to open the unprocessed semiconductor wafer W into the gate valve 30.
It is carried into the processing container 26, which has been evacuated in advance, through the above, and is supported by the notch step portion 38 at the upper end of the support 36A of the support member 36. Next, the gate valve 30 is closed to hermetically seal the inside of the processing container 26. Then, controlled electric power is supplied to the upper heating means 70 arranged on the ceiling portion 26B of the processing container 26 and the lower heating means 72 arranged on the bottom portion 26A to heat the carbon wire heaters 74 and 76, respectively. Here, the heat ray generated from the carbon wire heater 74 on the upper side passes through the ceiling plate 26B made of quartz and hits the upper surface (front surface) of the wafer W to heat it, and the heat ray generated from the carbon wire heater 76 on the lower side. Passes through the quartz container bottom portion 26A and the quartz suction head 42 and hits the lower surface (back surface) of the wafer W to heat it, so that the wafer W is quickly heated to and maintained at a predetermined process temperature. It
At the same time, the necessary processing gas is supplied from the ring-shaped gas nozzles 52 and 54 of the gas introduction unit 50 toward the processing space S, and the atmosphere in the processing container 26 is evacuated from the suction head 42 of the exhaust unit 40. Evacuation is performed and a predetermined heat treatment such as a film forming process is performed while maintaining the inside of the container at a predetermined process pressure.

As described above, according to the present invention, the upper heating means 70 and the lower heating means 72 are provided on both sides of the semiconductor wafer W to heat the wafer W from both sides. Since the temperature rate can be greatly improved, the temperature can be quickly raised to a predetermined process temperature, and as a result, the throughput can be significantly improved. Further, since the semiconductor wafer W can be heated and heated simultaneously from the upper and lower surfaces, the semiconductor wafer W can be heated with a small temperature difference between the upper surface and the lower surface of the wafer W, and therefore,
Since the temperature difference in the thickness direction of the wafer W is reduced, it is possible to prevent the wafer W from being warped and from being cracked such as slip.

Further, as a result of heating the wafer W from both sides, the temperature difference between the central portion and the peripheral portion of the wafer at the time of temperature rise can be suppressed to a very small level, so that the wafer It is also possible to suppress the occurrence of a difference in thermal history between the central portion and the peripheral portion. Furthermore, the gas nozzles 52 and 54 of the gas introduction unit 50, the support column 36A of the support member 36, and the suction head 42 of the exhaust unit 46.
Since each is formed of a light-transmissive member such as quartz, the heat rays absorbed therein are extremely small, and the heating efficiency for the wafer W can be improved. Also,
Since the atmosphere suction port 44 (see FIG. 3) of the suction head 42 is set to have a large diameter, the atmosphere in the container can be sucked and discharged from the outer peripheral side of the wafer W substantially uniformly.

Further, since the carbon wire heaters 74 and 76 having particularly good thermal responsiveness are used as the upper heating means 70 and the lower heating means 72, the temperature rising rate of the wafer W should be further improved accordingly. Is possible. Furthermore, the processing unit 24 includes a heat insulating layer 90 inside the outer housing 22.
Since it is accommodated through the processing unit 2,
It is possible to improve the heat retaining property of the whole No. 4 and to improve the heat efficiency accordingly. Here, since the temperature rising operation of the conventional apparatus and the apparatus of the present invention were compared, the evaluation results will be described. Here, a predetermined electric power is applied to raise the temperature to 800 ° C. As a result of applying the same amount of electric power to both heat treatment apparatuses as a whole, the heating rate was about 10 ° C./second in the conventional apparatus, but was about 15 ° C./second in the apparatus of the present invention, which is a large increase. It was found that the temperature rate can be improved. At this time, no warp or slip occurred on the semiconductor wafer.

When the temperature difference between the central portion and the peripheral portion on the wafer surface at the time of temperature rise was measured, it was 3 in the case of the conventional apparatus.
Although there was a temperature difference of about 0 to 40 ° C., in the case of the device of the present invention, the maximum temperature difference is about 8 ° C. as shown in FIG.
It turned out that this could be greatly improved. That is, FIG. 7 is a graph showing the relationship between time and wafer temperature, and four thermocouples (center portion, inner middle circumferential portion, outer middle circumferential portion, outer circumferential portion) at predetermined intervals along the radial direction of the wafer. Are placed and the temperature at each location is measured. According to this, the maximum temperature difference during the temperature rise of the wafer was about 8 ° C. Although the gas nozzles 52, 54 are formed in a circular ring shape here, it is needless to say that the shape is not limited to this, and for example, a straight tubular gas nozzle, a shower head-shaped gas nozzle, or the like may be used. Further, the shape of the carbon wire heaters 74 and 76 is not limited to the spiral shape as shown in FIG. 5, and may be formed in a concentric shape or the like.
Further, the carbon wire heaters 74 and 76 may be arranged concentrically to form a plurality of heating zones, and the temperature may be individually controlled for each heating zone. Furthermore, instead of the carbon wire heater, a normal resistance heater or heating lamp may be used.

Further, although the case where one processing unit 24 is housed in the outer casing 22 has been described here as an example, the present invention is not limited to this, and the processing unit 24 as described above as shown in FIG. A plurality of sets, in the illustrated example, three sets may be assembled into a stacked state, and the whole may be surrounded and covered by one vertically elongated metal outer casing 22. In this case, a heat insulating material 96 is interposed between the processing units 24 so as to block thermal influences between them. still,
The processing units 24 may be arranged side by side in the lateral direction. According to this, it is possible to save the installation area. Further, although the case where the film forming process is performed as the heat treatment has been described here as an example, the present invention is not limited to this, and the present invention can be applied to various heat treatments such as an oxidation diffusion process, an annealing process, and an etching process. is there. Further, the object to be processed is not limited to a semiconductor wafer, but can be applied to an LCD substrate, a glass substrate, or the like.

[0021]

As described above, according to the heat treatment apparatus and the heat treatment method of the present invention, the following excellent operational effects can be exhibited. Since the object to be processed is heated from both sides by the upper heating means and the lower heating means,
Not only it becomes possible to improve the throughput by improving the temperature rising rate without causing warping or slips on the object to be processed, but also between the central part and the peripheral part of the object to be processed at the time of temperature increase. It is possible to prevent a large temperature difference from occurring.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a heat treatment apparatus of the present invention.

FIG. 2 is a plan view showing an arrangement state of columns of a supporting member.

FIG. 3 is an enlarged cross-sectional view showing a suction head of exhaust means.

FIG. 4 is a plan view showing an arrangement state of gas nozzles of a gas introducing unit.

FIG. 5 is a plan view showing a heater wire of a heater unit.

FIG. 6 is a schematic configuration diagram showing a modified example of the heat treatment apparatus of the present invention.

FIG. 7 is a graph showing the relationship between time and wafer temperature.

FIG. 8 is a schematic configuration diagram showing a conventional single-wafer-type heat treatment apparatus.

[Explanation of symbols]

20 Heat treatment equipment 22 Outer case 24 processing units 26 Processing container 26A bottom 26B ceiling 36 Support member 36A prop 40 Exhaust means 42 Inhalation head 50 Gas introduction means 52,54 gas nozzle 70 Upper heating means 72 Lower heating means 74,76 carbon wire heater 78,80 block W Semiconductor wafer (Processing object)

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Claims (10)

[Claims] 1. A heat treatment apparatus having a treatment unit for subjecting an object to be treated to a predetermined heat treatment, wherein the processing unit comprises a treatment container formed of a light-transmissive member, and a support member for supporting the object to be treated. An upper heating means provided outside the ceiling part of the processing container, a lower heating means provided outside the bottom part of the processing container, a gas introducing means for introducing a processing gas into the processing container, and the processing A heat treatment apparatus comprising: an exhaust unit configured to exhaust the atmosphere in the container. 2. The heat treatment apparatus according to claim 1, wherein the upper heating means and the lower heating means each have a carbon wire heater. 3. The heat treatment apparatus according to claim 1, wherein the support member has a column made of a light transmissive member. 4. The heat treatment apparatus according to claim 1, wherein the heating unit has a gas nozzle made of a light transmissive member. 5. The heat treatment apparatus according to claim 1, wherein the exhaust unit has an intake head made of a light-transmissive member having a large-diameter atmosphere intake port. 6. The heat treatment apparatus according to claim 1, wherein the light transmissive member is quartz. 7. The processing unit is integrally covered with an outer casing made of metal.
7. The heat treatment apparatus according to any one of 6 to 6. 8. The heat treatment apparatus according to claim 1, wherein a plurality of sets of the processing units are assembled and the whole is covered with an outer casing made of metal. 9. A heat treatment method in which an object to be treated is housed in a treatment container capable of supplying a predetermined gas and exhausting an internal atmosphere, and subjecting the object to the predetermined heat treatment. Predetermining the object to be processed by simultaneously irradiating the object to be processed with heat rays from both the upper heating means provided above the object and the lower heating means provided below the object. The method for heat treatment is characterized in that it is heated up to the temperature. 10. The processing container is formed of a light-transmissive material, the upper heating means and the lower heating means are respectively installed outside the processing container, and the heat rays pass through the processing container. 10. The heat treatment method according to claim 9, wherein the object to be processed is irradiated.