JP2003124206A - Heat treatment unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a sealing member at the circumferential edge of a window for isolating a processing chamber of a processing container from a lamp heater containing chamber against fusion or evaporation due to a high temperature. SOLUTION: The circumferential edge 25 of a window is composed of an opaque member and a protrusion 151 projecting along the concave surface of the window is provided on the upper surface at the flange part 150 of a processing container for supporting the circumferential edge of the window.

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 performing heat treatment on an object to be processed such as a semiconductor wafer using a lamp heater or the like.

[0002]

2. Description of the Related Art In order to manufacture a semiconductor integrated circuit, various heat treatments such as a film forming process, an annealing process, an oxidation diffusion process, and a nitriding process are repeated a plurality of times on a silicon substrate such as a semiconductor wafer.

For the purpose of improving the yield and quality of these semiconductor manufacturing processes, the temperature of the silicon substrate is set to 1
RTP (Rapid Thermal Processing) that rapidly increases and decreases with a temperature gradient of about 00 to 200 ° C./s is adopted.

For example, in the case of the single-wafer type heat treatment apparatus for RTP 1 shown in FIG. 1 proposed by the applicant in Japanese Patent Application No. 2001-207867 filed on July 9, 2001, one silicon substrate Single-wafer chamber (processing chamber) 3 for accommodating and arranging an object to be processed 2 such as a glass substrate and the like, a dome-shaped quartz window 4 arranged in the single-wafer chamber 3, an upper part of the quartz window 4 or the outside It has a plurality of lamps 5 for heating such as halogen lamps arranged in the upper and lower parts.
As shown in FIG. 2, the lamp 5 has an arc-shaped irradiation portion, and a plurality of lamps are arranged in an annular shape to form one lamp row, and the lamp rows are arranged in a concentric circle shape. It

The quartz window 4 is an airtight partition between the lamp 5 and the object 2 to be processed as shown in the drawing. When the processing chamber 3 is maintained in a reduced pressure environment, the quartz window 4 is directed upward as shown in the drawing. It is formed in a convex dome shape, and the peripheral edge portion 4a is formed to have a thickness of about 30 mm to secure its strength, and the thinnest top portion 4b is set to, for example, about 7 mm. Peripheral portion 4a
Are fitted and supported in the recesses 14a of the side wall 14 of the device.

Heat rays (infrared rays) from the lamp 5 are uniformly radiated toward the object to be processed 2.

The processing chamber 3 is connected to, for example, a gate valve for introducing and receiving the object 2 to be processed at its side wall, and
The side wall or the quartz window 4 is connected to a gas supply nozzle for introducing a processing gas used for heat treatment (not shown).

In the single-wafer type RTP heat treatment apparatus 1 configured as described above, the object 2 is introduced into the processing chamber 3 through the gate valve and supported by the holder (placement portion) 7. During the heat treatment, a processing gas such as nitrogen gas is introduced from the gas supply nozzle. On the other hand, the heat rays emitted from the lamp 5 through the quartz window 4 are absorbed by the object 2 to be processed, and the temperature of the object 2 to be processed rises. The output of the lamp 5 is feedback-controlled based on the measurement result of a temperature sensor (not shown).

Although not shown, the holder 7 supporting the object 2 to be processed is configured to be rotatable, so that the object 2 to be processed is uniformly heat-treated. Note that the holder 7 is configured to be able to move up and down, if necessary.

Further, in Japanese Patent Laid-Open No. 11-45861,
It discloses a configuration in which an upper liner is provided below the upper dome. However, column 7, line 43 and subsequent lines of the publication describe that the side wall has a temperature of 400 to 600 ° C., and as a result, gas passes through the side wall and each liner part while these parts cause gas to flow. Is assumed to be heated. Further, in this configuration, it is considered that the upper liner is configured by a member different from the wall structure of the processing container, and as a result, the manufacturing / assembling process becomes complicated and the upper liner is attached due to a difference in thermal expansion coefficient. It is conceivable that problems such as peeling of the broken part may occur.

[0011]

The boundary between the lower surface of the peripheral edge portion 4a of the quartz window 4 and the concave portion 14a of the side wall 14 has a circular O shape with a configuration along the circular peripheral edge portion 4a.
A ring 15 is provided. This O-ring 15 is made of normal rubber, and maintains the airtightness between the peripheral edge 4a of the quartz window 4 and the recess 14a of the side wall 14 and the quartz window 4 directly in the recess 14a of the side wall 14. The function of preventing damage to the quartz window 4 due to contact is fulfilled.

However, as shown in FIG.
The light (heat ray) emitted from the O-ring 15 is also emitted to the O-ring 15 through the quartz window 4, so that the O-ring 15 is heated, and as a result, the O-ring 15 is melted, and when further heated, the The components may evaporate and adhere to the surface of the quartz window 4. In that case, quartz window 5
Of the object 2 to be processed by the lamp 5 is reduced as a result.
However, there is a problem that the predetermined treatment cannot be performed properly because the heating of the above is not sufficient. Also, the O-ring 15 is altered due to abnormal heating of the O-ring 15,
There is a possibility that the original functions of maintaining the airtightness and preventing the quartz window 4 from being damaged are not sufficiently fulfilled.

In order to avoid heating of the O-ring 15, it may be possible to displace the O-ring 15 further outward. However, as a result, the outer diameter of the dome-shaped quartz window 4 increases, and the central portion 4b of the window 4 is correspondingly increased.
Will project upwards, resulting in the need to increase the distance between the lamp 5 and the wafer 2. Such a large distance between the lamp 5 and the wafer 2 hinders efficient heating of the wafer 2 and reduces the efficiency of the heat treatment. Therefore, it is difficult to adopt the solution by shifting the installation position of the O-ring 15 to the outer peripheral side.

The present invention has been made in view of the above problems, and abnormal heating of the sealing member such as the O-ring 15 provided around the quartz window 4 due to the irradiation of the lamp 5 for heating the object to be processed is performed. An object of the present invention is to provide a structure of a heat treatment apparatus which can be prevented.

Further, it is possible to prevent a situation in which a heat ray due to secondary radiant heat from a member to be processed (wafer) is directly applied to the window, and as a result, the window is heated to heat the member such as the O-ring. It is also intended to provide a configuration to obtain.

[0016]

In order to achieve this object, according to the present invention, in a heat treatment apparatus for performing heat treatment on an object to be processed by using a lamp heater, a process for treating the object to be processed in its processing container. A transparent window having a dome-shaped curved structure that hermetically separates the chamber from the lamp chamber that houses the lamp heater is provided, and the peripheral portion of the window supported by the processing container is formed of an opaque member. A projecting portion that projects along the curved surface in the vicinity of the peripheral portion of the window is provided in a portion supporting the peripheral portion of the window.

Since the peripheral portion of the window is made of the opaque member as described above, the light energy from the lamp heater is blocked by the opaque member, and the O-ring and other members for sealing the peripheral portion of the window are abnormally heated. Can be prevented.

Further, since a protrusion protruding along the curved surface in the vicinity of the peripheral portion of the window is provided in a portion supporting the peripheral portion of the window of the processing container, the peripheral portion of the window is supported through the window. It is possible to block the passage of the light energy (heat rays) that is reflected on the portion to be covered (the upper surface of the flange portion) and then radiated to the peripheral portion of the window again, and the peripheral portion of the window is heated by the reflection of the flange portion of the processing container. Can be prevented. as a result,
It is possible to prevent abnormal heating of a seal member such as an O-ring provided around the periphery of the window.

In the present invention, cooling means for directly cooling the peripheral portion of the window may be provided. By doing so, it is possible to effectively cool the peripheral portion of the window, and it is possible to more effectively prevent abnormal heating of a member such as an O-ring provided around the peripheral portion of the window.

Further, the side wall surface of the processing container may be substantially flush with the boundary surface between the peripheral portion of the window and the other portions. As a result, it is possible to effectively prevent abnormal heating of the members around the peripheral portion of the window without lowering the energy efficiency of the heat treatment of the object by the light energy transmitted through the window by the lamp heater.

Further, the protrusion may be formed integrally with the wall structure of the processing container. As a result, the manufacturing / assembling process can be simplified, and there is no fear of peeling due to the difference in the coefficient of thermal expansion, as compared with the case where it is configured separately, and reliability can be ensured.

Furthermore, it is desirable that the inner wall surface of the peripheral portion of the side wall having the above-mentioned protruding portion is subjected to a mirror surface treatment to form a mirror surface portion. This mirror surface portion also reflects the secondary radiant heat from the member to be processed (wafer) and also prevents the heat rays from being directly applied to the window due to the structure, and thus prevents the heating of members such as the O-ring. Is possible.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a heat treatment apparatus according to the present invention will be described below with reference to the drawings.

First, the heat treatment apparatus according to this embodiment will be described with reference to FIGS. 3 and 4.

The heat treatment apparatus 10 according to this embodiment is basically the same in structure as the heat treatment apparatus 1 of the conventional example described above. Therefore, of the constituent elements of the heat treatment apparatus 10, common elements are designated by the same reference numerals as those of the heat treatment apparatus 1 unless otherwise specified, and redundant detailed description will be omitted.

FIG. 3 shows a heat treatment apparatus 10 according to an example of the present invention.
FIG. Reference numeral 100 denotes a flat processing container made of, for example, aluminum, and the inner surface of the heat processing space has a circular transverse cross-section. Processing container 1
The bottom edge of 00 is formed as a ring-shaped groove 91, and an inner ring portion 110 is provided in the groove 91. The inner ring portion 110 is held on the inner wall of the groove portion 91 via a bearing portion 41 so as to be rotatable about a vertical axis.

At the upper end of the inner ring portion 110, a ring-shaped mounting portion 7 for holding the peripheral edge of the wafer 2 to be processed is provided, and rotates together with the inner ring portion 110.

On the other hand, the housing 53 forming the groove portion 91 which is a part of the processing container 100 extends downward,
The outer ring portion 54 is provided on the outer side of the housing 53 and the bearing portion 33.
It is held rotatably about a vertical axis via.

Magnetic poles 31 and 61 are provided on the inner ring portion 110 and the outer ring portion 54, respectively, and these magnetic poles 31 and 61 are arranged inside and outside the partition wall 52 of the housing 53 to form a magnetic coupling. There is.

A gear portion 63 is provided on the outer peripheral surface of the outer ring portion 54.
This gear portion 63 is engaged with a gear portion of a stepping motor (not shown), and the outer ring portion 54 is rotated by driving the stepping motor.

At the bottom of the processing container 100 below the wafer 2, the wafer 2 (not shown) is pushed up to process the processing container 100.
A lift pin is provided for transferring between the transfer arm and the outside of the transfer arm. A gas supply path 71 for supplying a processing gas and an exhaust path 72 for exhausting the processing gas are formed on a side wall of the processing container 100 slightly above the wafer 2 so as to face each other.

In the heat treatment apparatus 10 having the above structure, the wafer 2
The processing chamber 3 for processing the above has an airtight structure, and the inner ring portion 110 is also housed in this airtight structure and is separated from the external drive mechanism. Also, a lamp chamber 9 for accommodating the lamp 5
5 is airtightly separated by a dome-shaped quartz window 4 '. The O-ring 15 serves as a seal at that time.

Next, the part relating to the dome-shaped quartz window 4 ', which is a characteristic configuration of the present invention, will be described in detail.
The dome-shaped quartz window 4'is the above-mentioned conventional heat treatment apparatus 1
The dome-shaped quartz window 4 has the same structure as the dome-shaped quartz window 4 except for the following differences. In FIG. 3, the portion of the processing container 100 that supports the quartz window 4 ′ is the flange portion 150. An annular O-ring 15 is inserted between the upper surface of the flange portion 150 and the lower surface of the peripheral edge portion of the quartz window 4 ′ along the entire circumference of the peripheral edge portion (in the cross section) of the window. As mentioned above, this dome-shaped quartz window 4'is basically the same as the dome-shaped quartz window 4 used in the above-described prior art heat treatment apparatus 1. However, the dome-shaped quartz window 4'in this embodiment is used.
In the case of, the peripheral portion of the quartz window 4'is constituted by an opaque quartz portion 25 which is a separate member from the transparent quartz portion 24 in the central portion, and both are fixedly joined to each other at their joints 26, for example, by welding or the like, It is an integrated structure.

Further, the cylindrical inner upper end surface portion of the flange portion 150 supporting the quartz window 4'is
Along the entire circumference of the window edge (annular in cross section)
A protrusion 151 is provided. FIG. 4 is an enlarged vertical sectional view showing a peripheral portion of the dome-shaped quartz window 4'of FIG. As shown in FIG. 4, the protrusion 151 is provided in a ring shape along the periphery of the dome-shaped quartz window 4 ′, and the upper portion thereof projects upward, so that the upwardly outwardly inclined surface 151 a is formed. It is configured to fit along the curved concave surface of the dome-shaped quartz window 4'which is curved in a dome shape.

Further, as shown in FIG. 4, the transparent quartz portion 2 is
The interface 26 between the 4 and the opaque quartz portion 25 is flush with the inner wall surface 100a of the processing container 100 above and below (it forms the same surface or a continuous surface, that is, there is no step, neither protrudes from each other, nor is it recessed. State). Further, as shown in FIG. 4, a refrigerant passage 81 is provided for cooling the lamp chamber 95 and the dome-shaped window 4 ′, and the refrigerant passage 81 is further provided with a branch passage 81 a, The coolant is directly supplied not only to the upper surface of 4 ', but also to the opaque quartz portion 25 at the peripheral portion thereof.

Next, the operation of the above embodiment will be described. First, the wafer 2 is transferred to the mounting unit 7 from a transfer arm (not shown) carried in from a transfer port (not shown) of the processing container 100. Then, the above-mentioned stepping motor is driven to rotate the outer ring portion 54. At that time, the magnetic pole 61 of the outer ring portion 54
A magnetic force acts between the inner ring portion 110 and the magnetic pole 31 of the inner ring portion 110, and the inner ring portion 110 rotates due to the function of the above-described magnet coupling, and the mounting portion 7 fixed to the inner ring portion 110 also rotates.

In this way, the wafer 2 is, for example,
While rotating at 70 rpm, the radiant heat from the lamp 5
The wafer 2 is heated to further process gas from the gas supply path 71.
And a predetermined heat treatment is performed on the wafer 2.
For this heat treatment, the wafer 2 is heated to, for example, 1000 ° C.
Oxidation treatment (R
(TO) and the temperature of the wafer 2 is raised to, for example, 1000 ° C.
An inert gas such as N _TwoAnnealing process performed by supplying
(RTA) or heating the wafer 2 to, for example, 600 ° C.
Film formation process (CV
D) etc.

After the heat treatment is completed in this way, the lamp 5 is turned off to lower the temperature of the wafer 2, and after the wafer 2 reaches a predetermined temperature, the stepping motor is stopped. When the outer ring portion 54 stops, the inner ring portion 110 also stops,
The processed wafer 2 is unloaded from the processing container 100 by a transfer arm (not shown).

FIG. 5 shows an example of temperature / pressure control schedule in these heat treatments. Further, FIG. 6 shows the arrangement of each heat treatment apparatus when a plurality of heat treatment apparatuses are arranged. As shown in the figure, each of the above-mentioned treatments is carried out by a dedicated heat treatment apparatus, and the respective treatment apparatuses are arranged around the central hexagonal transfer chamber in the example of FIG. The processing chamber therein is decompressed, and the wafer is taken out under reduced pressure and transferred to the processing chamber of the next processing apparatus through the central transfer chamber. Then, when it is carried into the processing chamber of the next processing apparatus, it is returned to normal pressure and a predetermined processing is performed. Therefore, the pressure inside the processing chamber of the processing apparatus is reduced before and after the processing for transporting for the next processing, and the pressure difference between the lamp chamber 95 and the processing chamber 3 at that time causes the window 4 '.
It has a dome shape to prevent damage.

The operation focusing on the structure near the peripheral portion of the dome-shaped quartz window 4'will be described below.

First of all, the dome-shaped quartz window 4 '
Since the opaque quartz portion 25 is formed only at the peripheral edge of the lamp and the central transparent quartz portion 24 is joined by welding, the light energy emitted from the lamp 5 is blocked by the opaque quartz portion 25. , The heat energy transmitted to the O-ring 15 is considerably reduced.

However, considering only this structure, that is, the case where the protrusion 151 is not provided, the light emitted from the lamp 5 is reflected by the upper surface of the flange (shown by the broken line) as shown by the broken line in FIG. By irradiating the lower surface of the dome-shaped window 4 ′ with the reflected light, the portion of the opaque quartz portion 25 near the O-ring 15 is heated, and as a result, the amount of heat reaching the O-ring increases.

To solve this problem, the flange portion 150 is provided with the protruding portion 151 protruding upward as described above. Due to the presence of the protrusion 151, the light energy reflected on the upper surface of the flange portion 150 and applied to the lower surface of the window 4'as described above can be significantly reduced. The configuration of the protrusion is not limited to this example, and any other structure can be used as long as it is a configuration that transmits the light through the window 4'and then reflects off the side wall of the processing container to irradiate the window 4'again. Anything is fine. Further, it is not always necessary to integrate it with the flange portion 150, and it is possible to form it separately. However,
From a manufacturing point of view, the protrusion 151 having the structure as illustrated is currently advantageous.

The protrusion 151 is formed in the processing container 100.
Is integrally formed with the side wall of the. as a result,
The manufacturing and assembling steps can be simplified, and problems such as peeling due to the difference in the coefficient of thermal expansion can be prevented as compared with the case where they are formed separately, and the reliability of the device can be secured.

Further, the opaque quartz portion 2 of the window 4 '
In order to suppress the heating of No. 5, the refrigerant passage 81 is provided with the branch passage 81a as described above, and the refrigerant is directly blown to the opaque quartz portion 25 through the branch passage 81a, and as a result, the opaque quartz portion 25 is effectively cooled. Opaque quartz part 25
It is possible to prevent the O-ring 15 from being deteriorated, melted and evaporated due to the temperature rise due to the heating of the.

The reason why the surface of the welded portion 26 is flush with the inner wall surface of the processing container 100 above and below is as follows. That is, it is possible to suppress the heating of the O-ring 15 by the radiant heat from the lamp 5 by widening the range of the opaque quartz portion 25 in the inner peripheral direction of the window 4 ′. Of these, the radiant heat from the lamp 5 on the outer peripheral side of the processing container 100 is blocked by the opaque quartz portion 25 also present on the inner peripheral side in this way, so that the effective heat treatment of the wafer 2 by the radiant heat of the lamp 5 is performed. Disturbed. Therefore, as described above, in order to prevent the effective heating of the wafer 2 by the lamp 5 and effectively prevent the abnormal heating of the O-ring 15, the transparent quartz portion 2 is used.
4 and the opaque quartz portion 25 are preferably flush with the inner wall surface of the processing container 100 above and below the boundary surface.

As a result of simulation by the inventor, the temperature of the O-ring 15 rises to 432 ° C. when the conventional window 4 is entirely transparent quartz, but only up to 297 ° C. when the peripheral portion is opaque quartz. When the protrusion 151 is not provided, the temperature does not rise to 233 ° C., and when the cooling branch passage 81a is further provided, the temperature does not rise to 205.
The result obtained was that the temperature rose only to ℃. As described above, it was proved that the temperature rise of the O-ring 15 can be effectively prevented by adopting the structure of the present invention.

In the structure described in the above-mentioned publication (JP-A-11-45861), the side wall is 400 to 600 ° C. as described above.
However, in the configuration of the present invention, when the side wall of the processing chamber 3 has a high temperature of 400 to 600 ° C., the O-ring 15 may be heated and melted. On the other hand, in the present invention, the projection 151 (see FIG. 3) is provided as described above, and the peripheral portion of the window 24 is the opaque member 24a.
Further, as shown in FIG. 4, since the refrigerant passage 81a was provided, it was confirmed by experiments that the heating of the protrusion 151 (side wall portion) was moderated and the temperature became 50 ° C. or less. The side wall is made of, for example, aluminum and has a heat resistance temperature of about 200 ° C. In this case, if the temperature of the part is suppressed to 50 ° C. or less, problems such as material deterioration due to heat of the side wall can be prevented. It is possible.

Further, in the present invention, as shown in FIGS. 3 and 4, the inner wall surface of the peripheral portion of the side wall having the projection 151 is mirror-finished to form the mirror-surface portion 151b. The mirror surface portion 151b also reflects the secondary radiant heat from the wafer 2, and the heat ray is also directly reflected by the window 4 ′ due to the structure.
It is possible to prevent irradiation of the O-ring 15, and to prevent the O-ring 15 from being melted by heating.

[0050]

As described above, according to the present invention, the peripheral portion of the dome-shaped window for airtightly separating the processing chamber and the lamp chamber is made of an opaque member, so that an O-ring around the peripheral portion of the window is formed. Of the inner wall of the processing container is provided with a protrusion so as to protect the sealing member and the like from high heat and along the curved concave surface of the peripheral edge of the dome shape. By preventing the light reflected by the window supporting portion from irradiating the peripheral portion of the window, it is possible to more effectively prevent the temperature rise of the peripheral member of the peripheral portion of the window.

Further, by mirror-finishing the inner wall surface of the peripheral portion of the side wall having the above-mentioned protruding portion to form a mirror-surface portion, the mirror-surface portion is used to remove a portion from the member to be processed (wafer).
It is also possible to reflect the subsequent radiant heat, prevent the heat rays from being directly applied to the window, and prevent the heating of members such as the O-ring.

Further, by forming the protrusions integrally with the wall structure of the processing container, it is possible to avoid an increase in the number of steps due to the addition of the protrusions, and to prevent peeling and the like compared with the case of a separate structure. Problems can be prevented and reliability can be secured.

[Brief description of drawings]

FIG. 1 is a side sectional view of a conventional heat treatment apparatus as an example.

FIG. 2 is a plan view showing a configuration example of a lamp heater.

FIG. 3 is a vertical sectional view of a heat treatment apparatus according to an embodiment of the present invention.

FIG. 4 is an enlarged vertical cross-sectional view showing the vicinity of the peripheral portion of the dome-shaped window of FIG.

5 is a diagram showing an example of a temperature / pressure management schedule in heat treatment using the heat treatment apparatus shown in FIG.

6 is a layout diagram of an example of a semiconductor processing system to which a plurality of heat treatment apparatuses shown in FIG. 3 are applied.

[Explanation of symbols]

2 wafer (object to be processed) 3 processing chamber 4'dome-shaped quartz window 5 lamp (lamp heater) 7 mounting part (mounting table) 10 heat treatment device 15 O-ring 24 central part of window (transparent quartz part) 25 window Peripheral part (opaque quartz part) 26 Boundary surface (for example, welding surface) between the center part of the window and the peripheral part 81 Refrigerant passage 81a Refrigerant passage branch passage 95 Lamp chamber 100 Processing container 100a Processing container inner wall portion 150 Processing container flange Part 151 Projection part (projection part) 151a Inclined surface 151b Mirror surface part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mogumo             TBS release, 5-3-6 Akasaka, Minato-ku, Tokyo             Sending Center Tokyo Electron Limited F-term (reference) 4K030 CA04 FA10 JA10 KA24 LA15                 5F045 AA03 AA20 AB32 AC11 AD10                       AD14 AF03 BB20 DP02 DQ10                       EB02 EB10 EK12

Claims (5)

[Claims] 1. A heat treatment apparatus for performing heat treatment on an object to be processed using a lamp heater, wherein an airtight space is provided between a processing chamber for processing the object to be processed and a lamp chamber accommodating the lamp heater in a processing container. A transparent window having a dome-shaped curved structure that separates is provided, and the peripheral edge of the window supported by the processing container is made of an opaque member. A heat treatment apparatus provided with a protrusion protruding along a curved surface. 2. The heat treatment apparatus according to claim 1, further comprising cooling means for directly cooling the peripheral portion of the window. 3. The heat treatment apparatus according to claim 1, wherein an inner wall surface of the processing container is substantially flush with a boundary surface between a peripheral portion of the window and other portions. 4. The heat treatment apparatus according to claim 1, wherein the protrusion is integrally formed with a wall structure of the processing container. 5. The heat treatment apparatus according to claim 1, wherein the peripheral edge portion of the processing container provided with the protrusion is mirror-finished.