JP2002299275A - Heat treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment device, with which accuracy in the measurement of a wafer temperature can be improved by suppressing disturbance light except for light existent inside a reflection cavity space and radiated from a wafer to be made incident to a radiation thermometer for wafer temperature measurement. SOLUTION: In this heat treatment device, the disturbance light L2 existent inside the reflection cavity space 41 formed from the wafer W, a guard ring 31 and reflection plane 40 is absorbed and suppressed by a light-absorbing chip 45 provided on the reflection plane 40. The disturbance light L2 is light except for radiated light L1 from the wafer W to be made incident to radiation thermometers 43a-43c for measuring the temperature of the wafer W and contains radiated light L2a from the guard ring 31 and leaked light L2b from a lamp 12. The light absorbing chip 45 is almost fan-shaped and provided to be spread outside the reflection plane 40, while facing the guard ring 31 on the outside of an observation hole 42c in the direction of the diameter of reflection plane 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of irradiating a semiconductor substrate, a glass substrate for a liquid crystal display, a glass substrate for a photomask, a substrate for an optical disk, and the like (hereinafter, referred to as "substrate") housed in a processing chamber. The present invention relates to a heat treatment apparatus such as a lamp anneal for performing a heat treatment.

[0002]

2. Description of the Related Art Conventionally, in a manufacturing process of a substrate,
Various heat treatments have been performed. As a heat treatment apparatus for performing heat treatment on a substrate, for example, a rapid heating apparatus (so-called lamp annealing apparatus) for rapidly heating the substrate by light irradiation is used. In particular, as the demand for microfabrication of semiconductor devices and the like becomes more severe, a rapid heating process (RTP; Rapid Thermal P
rocess) is becoming important.

In general, a heat treatment apparatus such as a lamp annealing apparatus mainly uses an infrared halogen lamp as a heating source and irradiates light from the lamp in a predetermined gas atmosphere such as a nitrogen gas to thereby heat a substrate to a desired temperature in the order of seconds. (Up to 1200 ° C.), and after maintaining the substrate at that temperature for about several tens of seconds, the irradiation of light from the lamp is stopped to rapidly cool the substrate.

Such a lamp annealing apparatus can prevent re-diffusion of impurities due to heat in a bonding layer of a transistor formed on a substrate and can form an insulating film such as a thin oxide film. Processing that has been difficult to achieve by high-temperature heat treatment can be performed.

When heat treatment is performed in the lamp annealing apparatus, power supply to the lamp is controlled based on the measurement result while measuring the temperature of the substrate. Therefore, in order to perform an appropriate heat treatment, it is important to accurately measure the temperature of the substrate to be processed. In recent years, the temperature of the substrate has been measured in a non-contact manner by measuring the intensity of radiation emitted from the substrate. Temperature measurement using a radiation thermometer for measurement is becoming mainstream. As the radiation thermometer, for example, a pyrometer using a silicon photodiode having a measurement wavelength peak of 0.95 μm as a detection element is used, and is disposed on the opposite side of the substrate with respect to the lamp.

FIG. 7 is a side sectional view showing a partial configuration of a conventional heat treatment apparatus (lamp annealing apparatus). As shown in FIG. 7, the substrate W is supported at a predetermined position in the processing chamber PR by a support member 102 via a guard ring (heating ring) 101. Guard ring 101
Is provided to make the temperature of the substrate W uniform, has a plate-like annular shape formed of a light-absorbing material (here, SiC), and has an outer peripheral edge of the disk-shaped substrate W. The substrate W is held in contact with the portion from the outside. The support member 102 supports the substrate W via the guard ring 101 by supporting the outer edge of the guard ring 101 from below. Here, the support member 102 has a cylindrical shape, and is formed of quartz from the viewpoint of workability and cost reduction. The lamp (not shown) is provided above the processing chamber PR, and irradiates the substrate W with light from above.

Below the substrate W in the processing chamber PR, a reflecting surface 103 is provided substantially in parallel with the substrate W and the guard ring 101.
Is formed by the lower wall surface of the processing chamber PR. This reflecting surface 103 is used for the first radiation L radiated from the substrate W.
1 and a space sandwiched between the reflecting surface 103, the substrate W, and the guard ring 101 from above and below is a thin columnar reflecting cavity space 104 that multiple-reflects the first radiation L1. Has become.

A viewing window (through hole) 105 is provided at a position on the reflection surface 103 facing the treatment site of the substrate W, and a radiation thermometer (pyrometer) is provided outside the viewing window 105.
106 is provided. The radiation thermometer 106 measures the temperature of a predetermined portion of the substrate W by measuring the intensity of the first radiation L1 through the viewing window 105.

Here, the first radiation L1 incident on the radiation thermometer 106 through the viewing window 105 is the direct light L1a emitted from the substrate W and incident on the radiation thermometer 106.
And reflected light L1b which is emitted from the substrate W, is reflected a plurality of times between the reflection surface 103 and the substrate W, and then directly enters the radiation thermometer 106. This reflected light L1b is transmitted together with the direct light L1a. By making the light incident on the radiation thermometer 106, the characteristics at the time of temperature measurement are improved.

As described above, in order to accurately measure the temperature of the substrate W using the non-contact radiation thermometer 106, the substrate W
It is necessary to prevent disturbance light L2 other than the first radiation light L1 radiated from the infrared thermometer 106 from entering the radiation thermometer 106. As the disturbance light L2, there are a second radiation light L2a emitted from the guard ring 101 and incident on the radiation thermometer 106, and light L2b which is leakage light of light emitted by the lamp. In general, the leakage light L2b from the lamp is
However, as shown in FIG. 7, the leakage light L2b is reflected by the side wall surface 107 of the processing chamber PR, so that the quartz support member 10 is not used.
2, the light enters the reflective cavity space 104, is reflected in the reflective cavity space 104, and is reflected by the radiation thermometer 106.
In some cases.

[0011]

However, in the above-described conventional heat treatment apparatus, no countermeasures against disturbance light L2 are taken in the reflection cavity space 104.
The second radiated light L2a emitted from the guard ring 101 is reflected in the reflection cavity space 4 and the like, so that the disturbance light L2
As a result, there is a problem that the accuracy of the temperature measurement is reduced.

Also, when leak light L2b from the lamp enters the reflective cavity space 104 via the support member 102 or the like, the leak light L2b is reflected in the reflective cavity space 104 and radiates as disturbance light L2. Thermometer 10
6, which causes a problem that the accuracy of the temperature measurement is reduced.

In view of the above problems, the present invention can suppress disturbance light other than radiation light from a substrate which is present in a reflection cavity space and enters a radiation thermometer for measuring a substrate temperature. An object of the present invention is to provide a heat treatment apparatus capable of improving the temperature measurement accuracy.

[0014]

A technical means for achieving the above object is a heat treatment apparatus for irradiating a substrate housed in a processing chamber with light to perform a heat treatment, which is provided above the processing chamber. A light irradiating means for irradiating the light from above the substrate, and having a plate-like ring shape formed of a light-absorbing material, wherein the substrate is in contact with an outer peripheral edge of the substrate from outside in the processing chamber. A support member for supporting a substrate at a predetermined position in the processing chamber via the guard ring; and a substrate provided in the processing chamber below the substrate and the guard ring, wherein the substrate and the guard are provided. A reflecting means that has a reflecting surface provided substantially parallel to the ring and reflects the first radiation emitted from the substrate by the reflecting surface; and a reflecting surface of the reflecting means that is located at a position facing the substrate on the reflecting surface. Provided A radiation thermometer that measures the temperature of the substrate by measuring the intensity of the first radiation light through the through hole, and is formed by being vertically sandwiched between the substrate, the guard ring, and the reflection surface. In the reflection cavity space, at least a part of a path of disturbance light other than the first radiation light incident on the radiation thermometer through the through hole is provided to absorb or scatter the disturbance light. Light suppressing means for suppressing the light emission.

Further, a technical means for achieving the above object is a heat treatment apparatus for performing heat treatment by irradiating light to a substrate housed in a processing chamber. Light irradiation means for irradiating the light from above,
A substrate holding means for holding the substrate at a predetermined position in the processing chamber; and a reflecting surface provided below the substrate in the processing chamber and provided substantially in parallel with the substrate. Measuring the intensity of the first radiated light via a reflecting means for reflecting the radiated first radiated light and a through hole provided at a position of the reflecting surface of the reflecting means facing the substrate. A radiation thermometer for measuring the temperature of the substrate, and a radiation light incident on the radiation thermometer through the through hole in a reflection cavity space formed by being sandwiched between the substrate and the reflection surface from above and below. And a light suppressing unit provided to block at least a part of the path of the disturbance light other than the above, and suppressing or absorbing the disturbance light.

Further, preferably, the light suppressing means includes:
It is preferable that the hole is provided so as to cover at least a predetermined area of the through hole on a radially outer side of the reflection surface on the reflection surface.

[0017] Preferably, the light suppressing means is a predetermined area on the reflecting surface located radially outward of the through hole in the through hole and facing the guard ring. Is preferably provided so as to cover at least.

Further, preferably, the light suppressing means includes:
Of the light incident on the radiation thermometer through the through-hole as incident light into the reflection cavity space from the outer edge as the disturbance light, which is leakage light of the light irradiated by the light irradiation means, A substantially annular incident area on the reflecting surface, on which the reflected light that is reflected on the lower surface in the reflective cavity space and subsequently reflected on the upper surface in the reflective cavity space and incident on the through hole first enters, It is preferable to provide on the reflective surface so as to substantially cover at least a part of the section in the circumferential direction.

Preferably, the light suppressing means is a predetermined area on the reflection surface located radially outward of the through hole in the through hole, and a predetermined area facing the guard ring. Is provided so as to cover, and the predetermined area is leaked light of the light radiated by the light irradiating means, and enters the reflection cavity space from an outer edge portion as the disturbance light and enters the through-hole. Out of the light incident on the radiation thermometer via the first reflection light on the lower surface in the reflection cavity space, and then reflected twice on the upper surface in the reflection cavity space and incident on the through hole twice. It is preferable that a substantially annular predetermined area on the reflecting surface on which the light first enters is provided so as to substantially cover a predetermined section in the circumferential direction.

Further, it is preferable that the disturbance light includes the second radiation light radiated from the guard ring.

Preferably, the disturbance light includes:
It is preferable that leak light of the light emitted from the light irradiation unit and emitted into the reflection cavity space from the light irradiation unit is included.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Schematic Description of the Entire Apparatus> FIG. 1 is a side sectional view showing an overall configuration of a heat treatment apparatus according to an embodiment of the present invention, and FIG. It is the figure which expanded. The heat treatment apparatus in FIG. 1 is a so-called lamp annealing apparatus that performs a rapid heating process on a substrate W by light irradiation. This heat treatment apparatus is roughly divided into an upper lamp house 1 and a lower furnace wall 2.

The lamp house 1 is provided with a plurality of lamps (light irradiation longitudinal sections) 12 and the same number of reflectors 6. Inside each of the reflectors 6, a hole for inserting a lamp is formed coaxially with its central axis, and one lamp 12 is inserted into the hole from above. Each lamp 12 is an infrared halogen lamp in which a halogen gas is sealed in a cylindrical quartz tube and a cylindrical filament 3 is provided in the vicinity of a central axis thereof, because of required irradiation intensity, lamp life, and limitations on manufacturability. I have. The filament 3 is arranged so that its longitudinal direction is along the central axis of the quartz tube. Further, a filament lead-out terminal 4 for supplying electric power to the filament 3 is provided above each lamp 12.

The plurality of lamps 12 are regularly arranged around a predetermined axis of symmetry, and are divided into a plurality of groups for each adjacent group. The power supplied to the lamp 12 can be independently adjusted for each group by a control unit (not shown). As a specific example of the grouping, there is a method of concentrically grouping the central portion of the substrate W, the radially intermediate portion of the substrate W, and the light irradiation intensity on the edge portion so as to be individually adjustable. is there.

The reflector 6 is a reflecting mirror having an elliptical spherical shape, and reflects the light emitted from the lamp 12 downward (toward the substrate W).

On the lower surface of the base plate 8 provided on the upper part of the lamp house 1, the upper end of the reflector 6 is fixed. Each lamp 12 is fixed to the base plate 8 via the mounting flange 5 so as to be coaxial with the central axis of the reflector 6. Further, a plurality of water cooling paths 7 are provided inside the base plate 8, and are configured so that heat transmitted from the lamps 12 can be cooled.

A processing chamber PR for performing a heat treatment of the substrate W is formed inside the furnace wall 2. Further, a furnace port 21 for loading and unloading the substrate is formed on the furnace wall 2, and a shutter 22 is provided outside the furnace port 21. The shutter 22 can be opened and closed by an opening and closing mechanism (not shown). In a state where the shutter 22 is opened, the unprocessed substrate W is removed from the furnace port 21 by a transfer mechanism (not shown).
Can be carried into the processing chamber PR, and the processed substrate W can be carried out of the processing chamber PR. On the other hand, when the shutter 22 is closed (the state shown in FIG. 1), the processing chamber PR is sealed by the shutter 22 and a chamber window 23 described later via an O-ring (not shown), PR becomes an enclosed space.

The substrate W is supported at a predetermined position in the processing chamber PR by a support member 32 via a guard ring (heat equalizing ring) 31. This guard ring 3
1 and the support member 32 correspond to the substrate holding means according to the present invention.

The guard ring 31 is provided to make the temperature of the substrate W uniform, has a plate-like annular shape made of a light-absorbing material (here, SiC), and has a disk shape. The substrate W is held in contact with the outer peripheral edge of the substrate W from the outside. The support member 32 supports the substrate W via the guard ring 31 by supporting the outer edge of the guard ring 31 from below. Here, the support member 31 has a cylindrical shape, and is formed of quartz from the viewpoint of workability and cost reduction.

A magnet 35 is fixed below the support member 31. The magnet 3 is located on the lower side of the outside of the furnace wall 2.
A magnet ring 36 is provided at a position facing 5. The magnet ring 36 is engaged with the motor shaft of the motor 37, and rotates with the rotation of the motor 37. The magnet ring 36 and the magnet 35 exert an attractive force on each other by a magnetic force. When the magnet ring 36 rotates, the support member 32 on which the magnet 35 is fixed also rotates. When the support member 32 rotates, the substrate W supported thereon via the guard ring 31 also rotates about a predetermined rotation axis.

A chamber window 23 is provided inside the furnace wall 2 and above the processing chamber PR. Chamber window 23
Is made of quartz, has a function of transmitting light emitted from the lamp 12 downward and sealing the processing chamber PR.

The furnace wall 2 is provided with a gas inlet 38 and an exhaust port 39. The gas introduction port 38 and the exhaust port 39 are connected to a gas supply line and an exhaust line (not shown), respectively. Thus, a process gas such as a nitrogen gas and an oxygen gas can be supplied from the gas inlet 38 into the processing chamber PR, and the atmospheric gas in the processing chamber PR can be exhausted from the exhaust port 39.

Below the substrate W in the processing chamber PR, a reflecting surface 40 is formed by the lower wall surface of the processing chamber PR substantially parallel to the substrate W and the guard ring 31. The reflecting surface 40 reflects the first radiated light L1 radiated from the substrate W. The space sandwiched between the reflecting surface 40, the substrate W, and the guard ring 31 from above and below is the first surface. Is formed as a thin columnar reflecting cavity space 41 for multiple reflection of the emitted light L1.

In addition, viewing windows (apertures) 42a, 42b, and 42c are provided at positions on the reflection surface 30 opposite to the central portion of the substrate W, the radially intermediate portion of the substrate W, and the edge portion, respectively. Radiation thermometers (pyrometers) 43a, 43b, 43c are provided outside the viewing windows 42a, 42b, 42c, respectively. These radiation thermometers 43a, 4
3b and 43c measure the temperature of each part of the corresponding substrate W in a non-contact manner by measuring the intensity of the first radiation light L1 through each of the viewing windows 42a, 42b and 42c.

Here, as shown in FIG. 2, the first radiation light L1 entering the radiation thermometers 43a, 43b, 43c via the viewing windows 42a, 42b, 42c is radiated from the substrate W as shown in FIG. The direct light L1a that directly enters the thermometers 43a, 43b, and 43c, is emitted from the substrate W, is reflected a plurality of times between the reflection surface 40 and the substrate W, and then enters the radiation thermometers 43a, 43b, and 43c. The reflected light L1b is incident on the radiation thermometers 43a, 43b, and 43c together with the reflected light L1a, thereby improving the characteristics at the time of temperature measurement.

Next, an outline of a processing procedure in the heat treatment apparatus of FIG. 1 having the above configuration will be described. First, exhaust gas is exhausted from the exhaust port 39, and an inert gas (for example, nitrogen gas) is supplied from the gas inlet port 38 to the processing chamber PR.
The inside of the processing chamber PR is replaced with an inert gas atmosphere. Then, the shutter 22 is opened, and the unprocessed substrate W is carried in from the furnace port 21 and installed at a predetermined position. Next, the shutter 22 is closed to close the furnace port 21, and at the same time, a predetermined process gas is introduced from the gas inlet 38 to replace the periphery of the substrate W in the processing chamber PR with the atmosphere of the process gas.

Thereafter, power supply to the lamp 12 is started, and light irradiation from the lamp 12 is performed. Light emitted from the lamp 12 passes through the chamber window 23, reaches the substrate W, and rapidly heats the substrate W. When the light irradiation from the lamp 12 is performed, the substrate W is rotated by the motor 37. In addition, the substrate W is rotated at the time of light irradiation, and the center of the substrate W is measured by the radiation thermometer 43a, the edge of the substrate W is measured by the radiation thermometer 43c, the radiation thermometer 43b.
The temperature of an intermediate portion between the central portion and the edge portion of the substrate W is measured by the controller, and the control unit (not shown) controls the amount of power supplied to each lamp 12 based on the temperature measurement result of each region for each of the groups. are doing. More specifically, it is necessary to irradiate a larger amount of light as it is closer to the edge of the substrate W that emits a large amount of heat. Lamp 12 corresponding to the center
Is supplied with relatively small power.

Thereafter, when a predetermined time has elapsed and the heating process of the substrate W is completed, the irradiation of light from the lamp 12 is stopped. Then, an inert gas is supplied from the gas inlet 38 to the processing chamber PR. Finally, open the shutter 22 and open the furnace
1 is released, the processed substrate W is carried out of the apparatus, and a series of heat treatments is completed.

<Explanation of Principal Parts> In the heat treatment apparatus according to the present embodiment, as shown in FIG. 2, in the reflection cavity space 41, the viewing windows 42a, 42b, 42c (here, the viewing window 42c located at the outermost periphery). ) Via the radiation thermometer 43
a, 43b, 43c (in this case, the radiation thermometer 43c), a light absorbing chip (light suppressing means) 45 is provided so as to block at least a part of the path of the disturbance light L2 other than the first radiation light L1. ing. The light-absorbing chip 45 is a plate-like member formed of a light-absorbing material (for example, SiC ceramic), and absorbs incident light.

As the disturbance light L2, the second radiation light L2a emitted from the guard ring 31 and incident on the radiation thermometers 43a, 43b and 43c, and the light L2b which is the leakage light of the light irradiated by the lamp 12 are shown. is there. Generally, lamp 1
Although some measures are taken to prevent light L2b from leaking from entering the radiation thermometer 43c, the light L2b is reflected by the side wall surface 46 of the processing chamber PR as shown in FIG. Then, the light may enter the reflective cavity space 41 via the support member 32 made of quartz, be reflected in the reflective cavity space 41, and enter the radiation thermometers 43a, 43b, and 43c.

Therefore, in this embodiment, the light absorbing chip 4
5, the radiation thermometers 43a and 43 as disturbance light L2.
b, 43c and the second radiation light L2a and the leakage light L2
b and both are absorbed and suppressed.

Three radiation thermometers 43a, 43b, 43c
Of these, the radiation thermometer 43c located on the outermost periphery is most likely to receive the disturbance light L2, so in the present embodiment, the light absorption chip 45 is focused on the radiation thermometer 43c.
Take countermeasures.

Here, of the second radiated light L2a radiated from the guard ring 31, the reflection surface 40 and the substrate W
Alternatively, most of the light reflected from the guard ring 31 and incident on the radiation thermometer 43c or the like as the disturbance light L2 is transmitted from the radially outward side of the reflection surface 40 such as the peephole 42c to the peephole 4.
The light is incident on the radiation thermometer 43c or the like via 2c or the like.

The radiation thermometer 43c irradiates the light from the lamp 12 and wraps around the back surface of the substrate W as disturbance light L2.
Most of the leaked light L2b incident on the reflection cavity space 41 from the radially outer side of the reflection surface 40 such as the observation hole 42c.
And is reflected on the upper and lower surfaces in the reflection cavity space 41 and enters the radiation thermometer 43c and the like via the observation hole 42c and the like.

Correspondingly, in the present embodiment, as shown in FIG. 2, the light absorbing chip 45 is provided on the reflecting surface 40 at a predetermined radial position outside the reflecting surface 40 of the viewing hole 42c. A region is provided so as to cover at least a predetermined region facing the guard ring 31, whereby the second radiation light L2a and leakage light L2b serving as disturbance light L2 are efficiently incident on the light absorbing chip 45 and absorbed. I am trying to be.

Referring to FIGS. 3 to 6, a description will be given of the most preferable embodiment of the planar shape, size, and arrangement position of the light absorbing chip 45. FIG. As shown in FIG. 3, the leakage light L2b emitted from the lamp 12 and radiated to the backside of the substrate W to enter the radiation thermometer 43c as disturbance light L2 is applied twice on the upper and lower surfaces in the reflection cavity space 41. The twice reflected light L201 that is reflected and enters the peephole 42c
b, four times reflected light L202b which is reflected four times by the upper and lower surfaces in the reflection cavity space 41 and enters the viewing hole 42c, six times reflected light (not shown), and n times reflected light of the number of times of reflection (n is 8) (Even numbers above).

As described above, the leakage light L2 which becomes the disturbance light L2
b includes a plurality of types of light L201 depending on the difference in the number of reflections.
b and L202b are included, but the attenuation increases as the number of reflections increases due to the attenuation at the time of reflection. Therefore, the influence of the twice reflected light L201b as disturbance light L2 is the largest. Therefore, in taking measures against the leak light L2b, it is important how to suppress the twice reflected light L201b.

Here, the two-time reflected light L201b enters the reflective cavity space 41 from obliquely above, and is first reflected on the lower surface (reflective surface 40) in the reflective cavity space 41, and then is reflected on the reflective cavity space 41. Hole 42c reflected by the upper surface (guard ring 31 or substrate W)
Is incident on the radiation thermometer 43c through the.

Therefore, by disposing the light absorbing chip 45 at the incident position of the twice reflected light L201b on the reflecting surface 40, the twice reflected light L201b can be effectively suppressed.

FIG. 4 shows the radiation thermometer 43 as the disturbance light L2.
FIG. 9 is a diagram showing an annular incident area A on the reflection surface 40 of the twice reflected light L201b incident on the light incident surface c. In the configuration of FIG. 4, the outer diameter of the substrate W is 200 mm, and the inner and outer diameters of the guard ring 31 are set to 194 mm and 284 mm. In FIG. 4, reference numeral O1 indicates the center of the reflection surface 40, and reference numeral O2 indicates the center of the annular incident area A.

In the configuration shown in FIG. 4, the viewing hole 42c has the center O
1 at a distance D1 (D1 = 85 mm). Also, the center O2 of the annular incident area A
Is located at a distance D2 (D2 = 28 mm) from the center O1 on a straight line connecting the center O1 and the viewing hole 42c.
Then, as shown by hatching in FIG. 4, the annular incident area A is formed in an area between the circle having a diameter of 130 mm centered on the center O2 and the circle having a diameter of 190 mm on the reflection surface 40. ing.

Here, the annular incident area A may be obtained by theoretically calculating the path of the leakage light L2b of the lamp 12 based on the structure of the heat treatment apparatus, or may be obtained by actual measurement. . However, regardless of which method is used, the incident area A is determined by the distance from the peep hole 42c to the outer edge when the outer edge of the reflective cavity space 41 is viewed from the peep hole 42c on the reflection surface 40. It is generated with a predetermined width so as to overlap with a virtual circle passing through a position at a distance of two-thirds.

Therefore, in the present embodiment, by disposing the light absorbing chip 45 so as to cover at least a part of the annular incident area A in the circumferential direction, the two-time reflected light L2
01b is accurately incident on the light absorbing chip 45.

However, since the incident area A is distributed around the position facing the inner part of the substrate W as shown in FIG. 4, the light absorbing chip 45 is distributed over the entire area of the incident area A. If provided, the substrate W
Temperature uniformity of each and the radiation thermometers 43a, 43b, 4
3c may have an adverse effect on the temperature measurement accuracy. For this reason, it is necessary to provide the light absorbing chip 45 in a region that is the most effective in suppressing the disturbance light L2 in the incident region A and that is the minimum region where no adverse effect occurs.

In this regard, the inventor of the present patent application conducted the following test to determine the optimum planar shape, size, and arrangement position of the light absorbing chip 45.

First, as shown in FIG. 5, the planar shape of the light-absorbing chip 45 is a substantially fan-like shape which extends substantially radially outward of the reflecting surface 40 with the viewing hole 42c as a center. Regarding the disposition position, the substantially fan-shaped shape is set so as to extend radially outward of the reflection surface 40 from the peep hole 42c, and to substantially cover a predetermined circumferential section of the annular incident area A. Is set to The planar shape and the disposition position are such that the light absorbing chip 45 suppresses the disturbance light L2 incident on the observation hole 42c from a slightly wide direction while keeping the light absorbing chip 45 from contacting the substrate W as much as possible. For.

Further, the size (width) of the light absorbing chip 45 in the radial direction of the reflecting surface 40 is set substantially equal to the radial width of the annular incident area A. That is, in the present embodiment, the inner peripheral end and the outer peripheral end of the width in the radial direction of the reflection surface of the light absorbing chip 45 are a circle having a radius R1 (R1 = 62 mm) from the center O2 and a radius R2 (R2 = 95).
mm). In addition,
The circle having the radius R1 is a circle circumscribing the outer periphery of the viewing hole 42c, and the circle having the radius R2 is substantially a circle circumscribing the outer peripheral edge of the reflection surface 40.

The size of the light absorbing chip 45 in the circumferential direction is substantially the same as the central angle θ of the fan-shaped hole 42c.
Is defined by the size of Here, this central angle θ
Was changed in three steps of 48 °, 72 ° and 144 ° to determine the optimal size of the central angle θ.

FIG. 6 is a graph showing the test results. In the test shown in FIG. 6, a substantially fan-shaped light absorbing chip 4 was used.
5 as well as 30 mm in length and width as shown by a virtual line in FIG.
The test was performed when the rectangular light absorbing chip 45 was used and when the light absorbing chip 45 was not provided at all. This graph shows the radiation thermometers 43a, 43b, 4 from the reference temperature measured under ideal conditions at the center, middle, and edge of the substrate W under each set condition.
3c shows the magnitude of the deviation of the measured temperature (temperature difference range).

According to the result of the graph of FIG.
It can be seen that the measurement accuracy of the radiation thermometer 43c on the outermost periphery is greatly improved particularly when the angle is set to 4 °.
Also, as a result of the test, when the central angle θ is set to 144 ° or more, the effect of suppressing the disturbance light L2 by the light absorbing chip 45 is large, but the light absorbing chip 45 has a lower temperature and a lower temperature of the substrate W. It was found that the adverse effect on the measurement was greater.

Therefore, in this embodiment, the light absorbing chip 4
5 is set to a value within a predetermined range (144 ° here) based on 144 °.

As described above, according to the present embodiment, the light absorbing chip 45 provided as described above allows the second light from the guard ring 31, which is the disturbance light L 2, existing in the reflection cavity space 41. The radiation light L2a and the leakage light L2b from the lamp 12 can be effectively absorbed and suppressed, and the measurement accuracy of each radiation thermometer 43a, 43b, 43c (in particular, the radiation thermometer 43c) can be improved.

In particular, the planar shape of the light absorbing chip 45 on the reflecting surface 40 is such that the light absorbing chip 45 is
The light absorbing chip 45 is disposed in a substantially fan shape that extends substantially radially outward in the radial direction of 0, and the position of the light absorbing chip 45 is such that the substantially fan shape spreads radially outward of the reflection surface 40 from the viewing hole 42c. And the size (width) of the light absorbing chip 45 with respect to the radial direction of the reflecting surface 40 is set so as to substantially cover a predetermined section in the circumferential direction of the annular incident area A. The width of the incident region A in the radial direction is set to be substantially equal, and the central angle θ defining the size of the light absorbing chip 45 with respect to the circumferential direction is set to 144 °. The second radiation light L2a and the leakage light L2b (particularly the twice-reflected light L201b having particularly high intensity) incident on the radiation thermometer 43c are effectively absorbed by the light-absorbing chip 4 while minimizing the adverse effects on the temperature measurement.
5 can be suppressed.

<Modification> In this embodiment, the light absorbing chip 45 is provided as the light suppressing means. However, instead of the light absorbing chip 45, the reflection surface 45 absorbs the disturbance light L2 into a blackened region (for example, , A black body paint or the like). Alternatively, instead of the light absorbing chip 45, a light scattering region for scattering the disturbance light L2 (for example, a part of the surface of the reflection surface 45 may be a light scattering surface) may be provided on the reflection surface 45. A light scattering plate (for example, frosted glass or the like) that scatters L2 may be provided.

[0065]

According to the present invention, the light suppressing means provided in the reflection cavity space exists in the reflection cavity space and enters the radiation thermometer for measuring the substrate temperature. Disturbance light other than light emitted from the substrate can be suppressed, and measurement accuracy of the substrate temperature can be improved.

According to the third aspect of the present invention, when a guard ring is provided on the outer periphery of the substrate, of the radiated light radiated from the guard ring, the space between the reflection surface and the substrate or the guard ring is provided. Most of the light that is reflected at the radiation thermometer and enters the radiation thermometer as disturbance light enters the radiation thermometer through the through-hole from the radially outer side of the reflection surface of the through-hole,
The radiation light emitted from the guard ring and entering the radiation thermometer as disturbance light can be effectively suppressed by the light suppressing means.

In addition, most of the leakage light radiated from the light irradiating means, entering the radiation thermometer as disturbance light going around the back surface side of the substrate, is reflected from the radially outer side of the reflection surface of the through hole into the reflection cavity space. And is reflected on the upper and lower surfaces in the reflection cavity space and is incident on the radiation thermometer through the through-hole. It can be suppressed effectively.

According to the fourth aspect of the invention, of the radiated light emitted from the guard ring, the light reflected between the reflection surface and the substrate or the guard ring and incident on the radiation thermometer as disturbance light. Most of the light enters the radiation thermometer from the radially outer side of the reflection surface of the through-hole through the through-hole, so that the radiation emitted from the guard ring and entering the radiation thermometer as disturbance light is suppressed. Can be effectively suppressed.

In particular, the light suppressing means is provided so as to cover at least a predetermined area on the reflection surface, which is located radially outward of the reflection surface of the through hole and which faces the guard ring. Therefore, the radiation light from the guard link that enters the radiation thermometer as disturbance light can be effectively made incident on the light suppression means and suppressed.

Also, most of the leaked light radiated from the light radiating means and circulating to the back surface of the substrate and entering the radiation thermometer as disturbance light is transmitted from the radially outer side of the reflecting surface of the through hole to the reflecting cavity space. And is reflected on the upper and lower surfaces in the reflection cavity space and is incident on the radiation thermometer through the through-hole. It can be suppressed effectively.

According to the fifth aspect of the present invention, of the leakage light radiated from the light irradiating means, circling to the back side of the substrate and entering the radiation thermometer as disturbance light, the reflection in the reflection cavity space is included. The twice-reflected light, which has the smallest number of times and has the largest influence on the measurement of the substrate temperature, can be effectively made incident on the light suppressing means and suppressed.

According to the sixth aspect of the present invention, of the radiated light radiated from the guard ring, the light reflected between the reflection surface and the substrate or the guard ring and incident on the radiation thermometer as disturbance light. Most of the light enters the radiation thermometer from the radially outer side of the reflection surface of the through-hole through the through-hole, so that the radiation emitted from the guard ring and entering the radiation thermometer as disturbance light is suppressed. Can be effectively suppressed.

In particular, the light suppressing means is provided so as to cover a predetermined area radially outward of the reflection surface of the through-hole on the reflection surface and which faces the guard ring. Therefore, the radiation light from the guard link, which is incident on the radiation thermometer as disturbance light, can be effectively made incident on the light suppression means and suppressed.

Further, most of the leaked light radiated from the light irradiating means and entering the radiation thermometer as disturbing light circulating to the back surface side of the substrate is mostly reflected from the radially outer side of the reflection surface of the through hole into the reflection cavity space. And is reflected on the upper and lower surfaces in the reflection cavity space and is incident on the radiation thermometer through the through-hole. It can be suppressed effectively.

Further, since the light suppressing means is provided so as to be located radially outward of the reflecting surface of the through hole on the reflecting surface, the light suppressing means is capable of radiating light from the substrate in the reflecting cavity space. Adversely affecting the multiple reflection of the substrate temperature and the measurement accuracy of the substrate temperature can be minimized.

Further, among the leakage light radiated from the light irradiating means and circulating to the back surface side of the substrate and entering the radiation thermometer as disturbance light, the number of reflections in the reflection cavity space is the minimum, and The twice-reflected light having the greatest influence on the measurement can be effectively made incident on the light suppressing means and suppressed.

According to the seventh aspect of the invention, the second radiation light radiated from the guard link and entering the radiation thermometer as disturbance light can be effectively suppressed.

According to the eighth aspect of the present invention, it is possible to effectively suppress leakage light irradiated from the light irradiation means, entering the radiation thermometer as disturbing light that goes around the back surface of the substrate and is disturbed.

[Brief description of the drawings]

FIG. 1 is a side cross-sectional view showing an entire configuration of a heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the heat treatment apparatus of FIG.

FIG. 3 is a diagram illustrating an example of a path when light leaking from a lamp enters a radiation thermometer as disturbance light.

FIG. 4 is a diagram showing an annular incident area on a reflection surface of twice reflected light of leaked light from a lamp incident on a radiation thermometer as disturbance light.

FIG. 5 is a diagram showing a planar shape, a size, and an arrangement position of a light absorbing chip provided on a reflection surface.

6 is a graph showing a change in measurement accuracy of a substrate temperature when the planar shape, size, and arrangement position of the light absorbing chip shown in FIG. 5 are changed.

FIG. 7 is a side sectional view showing a partial configuration of a conventional heat treatment apparatus.

[Explanation of symbols]

 Reference Signs List 12 lamp 23 chamber window 31 guard ring 32 support member 40 reflecting surface 41 reflecting cavity space 42a, 42b, 42c viewing hole 43a, 43b, 43c radiation thermometer 45 light absorbing chip L1 first radiation light L2 disturbance light L2a second Synchrotron light L2b Leakage light PR Processing chamber W Substrate

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiyuki Kobayashi 4-chome Tenjin Kitamachi 1-chome, Horikawa-dori-Teranouchi, Kamigyo-ku, Kyoto F-term (reference) 2G066 AC01 AC11 AC16 BB01 CA20 4M106 AA01 CA31 DH02

Claims (8)

[Claims] 1. A heat treatment apparatus for performing heat treatment by irradiating light to a substrate housed in a processing chamber, wherein the light irradiating means is provided above the processing chamber and irradiates the light from above the substrate; A guard ring that has a plate-like ring shape formed of a light-absorbing material and abuts on the outer peripheral edge of the substrate from outside in the processing chamber to hold the substrate; A support member for supporting the substrate at a predetermined position in the processing chamber; and a reflecting surface provided in the processing chamber below the substrate and the guard ring, and provided substantially parallel to the substrate and the guard ring. A reflecting means for reflecting the first radiated light radiated from the substrate by a surface; and an intensity of the first radiated light via a through hole provided at a position of the reflecting surface of the reflecting means facing the substrate. Measuring A radiation thermometer for measuring the temperature of the substrate, and a radiation thermometer through the through-hole in the reflection cavity space formed by being sandwiched between the substrate and the guard ring and the reflection surface from above and below. A light suppressing unit provided so as to block at least a part of a path of disturbance light other than the first radiation light, and suppressing or suppressing the disturbance light by absorbing or scattering the disturbance light. . 2. A heat treatment apparatus for performing heat treatment by irradiating light to a substrate housed in a processing chamber, wherein the light irradiating means is provided above the processing chamber and irradiates the light from above the substrate; A substrate holding means for holding the substrate at a predetermined position in the processing chamber; and a reflecting surface provided in the processing chamber below the substrate and provided substantially in parallel with the substrate, and the reflecting surface is used to separate the substrate from the substrate. Measuring the intensity of the first radiated light via a reflecting means for reflecting the emitted first radiated light, and a through hole provided at a position of the reflecting surface of the reflecting means facing the substrate; A radiation thermometer that measures a temperature of the substrate by the radiation thermometer that is incident on the radiation thermometer through the through hole in a reflection cavity space formed by being vertically sandwiched between the substrate and the reflection surface. Outside of Provided so as to block at least a portion of the light path, and suppresses light suppression means the disturbance light absorbed or scattered by,
A heat treatment apparatus comprising: 3. The heat treatment apparatus according to claim 1, wherein the light suppressing unit is configured to set a predetermined region on the reflection surface, which is located radially outward of the through hole from the reflection surface. A heat treatment device provided so as to cover at least. 4. The heat treatment apparatus according to claim 1, wherein the light suppressing unit is a predetermined region located on a radially outer side of the through hole on the reflecting surface on the reflecting surface. A heat treatment apparatus is provided so as to cover at least a predetermined region facing the guard ring. 5. The heat treatment apparatus according to claim 1, wherein the light suppressing unit is a leakage light of the light irradiated by the light irradiating unit, and is the reflection cavity from an outer edge as the disturbance light. Of the light that enters the space and enters the radiation thermometer through the through hole, the light is first reflected on the lower surface in the reflective cavity space, and then reflected on the upper surface in the reflective cavity space. It is provided on the reflection surface such that the twice-reflected light incident on the through-hole substantially covers at least a part of the circumferential direction of the substantially annular incident region on the reflection surface on which the reflection light first enters. Characteristic heat treatment equipment. 6. The heat treatment apparatus according to claim 1, wherein the light suppressing unit is a predetermined area located on a radially outer side of the through hole on the reflecting surface on the reflecting surface. The predetermined region is provided so as to cover a predetermined region facing the guard ring, and the predetermined region is leakage light of the light radiated by the light irradiating means, and is the reflection cavity space from an outer edge portion as the disturbance light. Out of the light incident on the radiation thermometer through the through-hole and first reflected on the lower surface in the reflective cavity space, and subsequently reflected on the upper surface in the reflective cavity space and A heat treatment apparatus, wherein the heat treatment apparatus is provided so as to substantially cover a predetermined section in a circumferential direction of a substantially annular incident area on the reflection surface on which the reflected light twice incident on the hole is first incident. 7. The heat treatment apparatus according to claim 1, wherein:
The heat treatment apparatus according to claim 1, wherein the disturbance light includes second radiation light emitted from the guard ring. 8. The heat treatment apparatus according to claim 1, wherein the disturbance light is radiated from the light irradiating means and is incident on the reflection cavity space from the light irradiating means. A heat treatment apparatus comprising the light leakage light.