JP2003022982A - Heat treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment device, with which uniform radiation can be performed while having high efficiency in the radiation of a lamp without the deformation or the like of a quartz window. SOLUTION: In a heat treatment device 26, a quartz window 14 is provided while dividing a heating source chamber 20 arranged with a lamp heater 12 and a treatment chamber 22 to arrange an object 2 to be treated. The quartz window 14 is curved toward the side of the lamp heater 12 to be projected in the form of dome, and formed thin toward a central part 14b of the top. A reflector 28 is formed so that a peripheral edge can be drooped and a droop 28a can surround a peripheral edge 2a of the object 2 to be treated on the upper side.

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 that heats an object by using a lamp heater.

[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 RTP heat treatment apparatus 1 shown in FIG. 11, a single-wafer type chamber (processing chamber) 3 for accommodating and arranging one object 2 such as a silicon substrate or a glass substrate is provided. A quartz window 4 arranged in the single-wafer chamber 3, a plurality of lamps 5 for heating such as halogen lamps arranged above or below the quartz window 4, and an object 2 to be treated of the lamp 5. Has a reflector (reflecting plate) 6 arranged on the opposite side. As shown in FIG. 12, 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 plurality of concentric circles. It Further, the reflector 6 has a plurality of reflector portions individually covering the plurality of lamps 5 (not shown).

The quartz window 4 is formed in a plate shape by partitioning the lamp 5 and the object 2 to be processed as shown in the figure, or is formed in an annular shape capable of accommodating the object to be processed therein.
The quartz window 4 is formed to have a thickness of about 30 to 40 mm in order to secure the strength when the processing chamber 3 is maintained in a reduced pressure environment.

Heat rays (infrared rays) from the lamp 5 are uniformly radiated toward the object 2 to be processed by the reflector 6.

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 heat treatment apparatus 1 for RTP configured as described above, the object 2 is introduced from the gate valve into the processing chamber 3 and supported by the holder 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 to be processed 2 is configured to be rotatable, whereby the object to be processed 2 is uniformly processed. Note that the holder 7 is configured to be able to move up and down, if necessary.

[0010]

However, the single-wafer type heat treatment apparatus for RTP has various problems because the quartz window is as thick as about 30 to 40 mm as described above.

First, when a lamp utilizing a halogen cycle is used as a heating source, the encapsulating portion is 350 to
The temperature must be adjusted to 900 ° C. Therefore, a cooling fluid for temperature adjustment is circulated around the lamp, but at this time, the upper portion of the quartz window is cooled to a temperature lower than that of the processing chamber side by the cooling fluid, so that the processing chamber side is closed. It will be curved convexly.

Secondly, since the quartz window partially absorbs the heat ray, the irradiation efficiency of the heat ray to the object to be treated is lowered, and the heating efficiency is lowered depending on the thickness of the quartz window.

Thirdly, when the distance between the object to be processed and the lamp is increased due to the provision of the quartz window, the distance
Since the heat rays spread in proportion to the square, the directivity of the lamp deteriorates.

Here, the directivity means the degree to which the heat ray is irradiated to a predetermined position without being diffused. It is essential that each part of the object to be processed is uniformly heated by a plurality of lamps, but in this case, even if the heat rays are diffused and irradiated from the plurality of lamps, uniform heating of the object to be processed can be achieved. is not. On the contrary, assuming that multiple lamps have good directivity, uniform irradiation is performed and uniform heating of the object to be processed is achieved only by controlling the output of each lamp to a predetermined condition. To be done.

Therefore, in the conventional single-wafer type heat treatment apparatus for RTP, the deterioration of the directivity of the lamp is a major factor that hinders the uniform heating of the object to be processed. 13, the illuminance at the peripheral portion of the object to be processed is lower than the illuminance at the central portion of the object to be processed (in FIG. 13, the horizontal axis represents the distance 0 from the center of the object to be processed). As a result, the heated object has an uneven temperature distribution.

The present invention has been made in view of the above problems, and it is a first object of the present invention to provide a heat treatment apparatus in which the quartz window is not deformed or damaged.

A second object of the present invention is to provide a heat treatment apparatus in which the efficiency of irradiation of heat rays on the object to be processed is improved.

The present invention also provides a heat treatment apparatus capable of uniformly irradiating the object to be treated with heat rays.
The purpose of.

[0019]

A heat treatment apparatus according to the present invention is a heat treatment apparatus for performing heat treatment on an object to be processed by using a lamp heater, the lamp heater facing the object to be arranged. A lamp heater having a plurality of arranged lamps and a reflector provided on the back surface of the plurality of lamps, and partitioning a heating source section in which the lamp heater is arranged and a processing section in which an object to be processed is arranged. It is characterized in that a dome-shaped quartz window curved convexly toward the side is provided.

Here, examples of the object to be processed include a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display, a substrate for an optical disk, and the like. Also,
Heat treatments include rapid thermal annealing (RTA), rapid thermal chemical vapor deposition (RTCVD), rapid thermal oxidation (RTO) and rapid thermal nitridation (RTN).

According to the present invention, the quartz window is not deformed or damaged when the temperature is rapidly raised by the above structure. Further, the central portion of the quartz window can be made thinner than the peripheral portion, and thus the irradiation efficiency can be improved.

In this case, it is preferable that the quartz window has a plurality of convex lens portions formed so as to face each of the plurality of lamps, because the directivity of the lamp is improved.

Further, in this case, in the reflector, when the peripheral portion of the reflector corresponding to the peripheral portion of the object to be disposed hangs down and the hanging portion is provided, the reflector is separated from the object to be diffused laterally. A part of the applied heat rays can be reflected by the hanging part and applied toward the object to be processed, so to speak, the lamp space is expanded in a pseudo manner. This improves the irradiation efficiency of the lamp. Further, the irradiation distribution can be made uniform, and the peripheral portion of the object to be processed, which has been apt to be relatively low in temperature in the past, can be heated more reliably, so that the object to be processed can be uniformly heated as a whole. it can.

Further, in this case, it is more preferable that the hanging portion has an inclined surface that spreads toward the object side.

Further, in this case, the quartz window has an opaque quartz portion at the peripheral portion of the quartz window corresponding to the peripheral portion of the object to be disposed, and the opaque quartz portion is the heat ray of the lamp heater. When the reflective surface that reflects toward the object to be processed is provided, the irradiation efficiency can be improved by irradiating the object to be processed with part of the heat rays diffused and irradiated to the side.

Further, in this case, when the plurality of lamps are respectively arranged in a curved shape at an equal distance from the quartz window, the lamps in the peripheral portion are arranged closer to the object to be processed than in the conventional case. The directivity of the lamp in the peripheral portion can be increased. At this time, for example, by subjecting the central side and the outer side to zone division and controlling the irradiation conditions, it is possible to uniformly heat the object to be treated as a whole.

Further, in the above heat treatment apparatus in which the peripheral portion of the reflector corresponding to the peripheral portion of the object to be disposed is hung to provide the hanging portion, in the lamp heater, the reflector is equivalent to the reflector. Substitution with a flat plate having a reflectance is preferable because the device configuration is simplified and the device cost is low. Here, the alternative reflector is a basic one that is usually provided on the back surface of any lamp heater and reflects the heat rays of the lamp.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of a heat treatment apparatus according to the present invention (hereinafter referred to as an example of the present embodiment) will be described below with reference to the drawings.

First, the heat treatment apparatus according to the first example of the present embodiment will be described with reference to FIGS. 1 and 2.

The heat treatment apparatus 10 according to the first example of the present 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. The same applies to the other embodiments described below.

As shown in the schematic view of FIG. 1, the heat treatment apparatus 10 has a lamp heater 12 and a quartz window 14 as in the conventional example.

The lamp heater 12 has a lamp 16 and a reflector 18. For example, a plurality of lamps 16 are concentrically arranged in parallel with each other so as to face the object 2 to be processed such as a semiconductor wafer. The reflector 18 includes a plurality of lamps 16.
1, which is the rear surface of the lamp 16, is configured as an assembly of reflector portions provided for each lamp 16 so as to cover the lamp 16 above the lamp 16.

The quartz window 14 is a lamp heater 12.
The heating source section 20 in which the above is arranged and the processing section 22 in which the object to be processed 2 is arranged are partitioned and provided.

The form of the quartz window 14 is different from that of the conventional quartz window 4. That is, the quartz window 1
Reference numeral 4 is formed in a so-called dome shape, which is convexly curved toward the lamp heater 12 side. The quartz window 14 has a peripheral edge portion 14a formed in the same thickness as that of the conventional one, for example, about 30 mm. On the other hand, the thickness is gradually reduced toward the central portion 14b, which is the top portion, and the thinnest top portion has a thickness of, for example, 7 m.
It is about m. The peripheral edge 14a is fitted and supported in the recess 24a of the side wall 24 of the device.

The heat treatment apparatus 10 constructed as described above.
The quartz window is formed so as to curve upward in FIG. 1. Therefore, when the temperature is rapidly raised, the quartz window spontaneously bends downward in FIG. The quartz window is not deformed or damaged because a force that cancels out the force generated in the quartz window is generated.

For this reason, the central portion of the quartz window can be made thinner than the peripheral portion, whereby the amount of heat rays absorbed in the central portion of the quartz window is reduced, and the amount of permeation is correspondingly reduced. To increase.

Referring to FIG. 2, the illuminance distribution on the surface of the object to be processed, in other words, the temperature distribution has a mountain shape similar to that in FIG. 11, and the illuminance at the peripheral edge of the object to be processed is higher than the illuminance at the center of the object to be processed. As a result, the illuminance distribution is non-uniform, and no significant improvement effect from the conventional example can be seen in this respect.

Next, a heat treatment apparatus according to the second example of the present embodiment will be described with reference to FIGS. 3 and 4.

The heat treatment apparatus 26 according to the second example of the present embodiment has the same basic configuration as the heat treatment apparatus 10 according to the first example of the present embodiment.

As shown in FIG. 3, the heat treatment device 26 is provided with a hanging portion 28a in which the peripheral portion of the reflector 28 hangs down. The hanging portion 28a is formed above the object 2 to be disposed so as to surround the peripheral edge portion 2a of the object 2.

The heat treatment apparatus 26 configured as described above
The part of the heat ray radiated from the lamp 16 toward the side wall 24 is reflected by the hanging part 28a and is irradiated to the object 2 without being absorbed by the side wall 24a, so that the irradiation efficiency can be improved. it can.

Next, a heat treatment apparatus according to a first modification of the second example of the present embodiment will be described with reference to FIGS. 4 and 5.

As shown in FIG. 4, the heat treatment apparatus 30 according to the first modification is formed so that the hanging portion 32a of the reflector 32 has an inclined surface that spreads toward the object 2 side. The dish-shaped reflector 32 having the lamp 16 arranged on the bottom surface is arranged upside down.

In the case of the heat treatment device 26 described above, the hanging portion 2
The heat rays reflected by 8a tend to gather at the center of the object 2 to be processed.
Since the heat ray reflected by a is distributed to the peripheral portion of the object to be processed 2, the illuminance part distribution in the object to be processed 2 becomes flat and uniform irradiation can be obtained.

Next, a heat treatment apparatus according to a second modification of the second example of the present embodiment will be described with reference to FIG.

As shown in FIG. 5, the heat treatment apparatus 34 according to the second modification has a basic structure of the heat treatment apparatus 30 of the first example.
But with a peripheral edge 36a of the quartz window 36
However, it is formed of an opaque quartz material that is separate from the transparent body portion 36b, and is joined and integrated with the transparent body portion 36b.

The heat treatment apparatus 30 includes the quartz window 3
The heat rays transmitted through the transparent main body 36b of 6 are reflected by the surface of the peripheral edge 36a toward the object 2 without being absorbed by the side wall 24 and are radiated, so to speak, the peripheral edge 36a serves as a reflector. As a result, the irradiation efficiency is more uniform and higher than that of the heat treatment device 26.

Next, a heat treatment apparatus 38 according to a third modification of the second example of the present embodiment will be described with reference to FIGS. 6 and 7.

The basic structure of the heat treatment apparatus 38 is the same as that of the heat treatment apparatus 30 according to the first modification.

As shown in FIG. 6, the heat treatment apparatus 38 is not provided with a reflector composed of a plurality of reflectors on the back surface of the lamp 16 of the lamp heater 40 having the lamp 16, and instead of this, the lamp 16 is used. The heat treatment apparatus 30 is different from the heat treatment apparatus 30 in that a flat plate 31 having the same reflectance as the reflector is provided on the back surface of the. However, like the heat treatment apparatus 30, a hanging portion 40a having a reflector action is provided.

The heat treatment apparatus 38 has a simple structure because the individual reflector portions are omitted, and therefore the apparatus is downsized and the cost of the apparatus is low.
In the heat treatment apparatus 38, the presence of the hanging portion 40a provides uniform irradiation as in the case of the heat treatment apparatus 30 of FIG. 5, due to the presence of the hanging portion 40a, although the reflector is omitted.

Next, a heat treatment apparatus according to the third example of the present embodiment will be described with reference to FIGS. 8 and 9.

The heat treatment apparatus 42 according to the third example of the present embodiment is basically the same as the heat treatment apparatus 26 according to the second example of the present embodiment or its first to third modifications. Three
The same as 0, 34, and 38.

As shown in FIG. 8, the heat treatment apparatus 42 has a distance L1 to LN between each lamp 16 and the quartz window 14.
Such that the plurality of lamps 16 and the reflector 46 forming the lamp heater 44 are arranged in parallel so as to face the quartz window 14 so as to be equal to each other, corresponding to the shape of the curved quartz window 14. This is different from the second example of the present embodiment.

Further, the heat treatment apparatus 42 measures the temperature distribution of the object to be processed 2 in real time by a temperature sensor (not shown), and based on the data, an output controller (not shown) controls the plurality of lamps 16 to move to the central portion A. And 2 of peripheral part B
Irradiation is controlled by dividing the zone into zones.

In the heat treatment device 42 according to the third example of the present embodiment, the lamp 16 in the peripheral portion is arranged closer to the object to be processed than in the conventional example and the above-described other example embodiments. The directivity of the lamp in the peripheral portion can be increased.
Further, as shown in FIG. 9, the central side (inside in the figure) and the outer side (inside, outside) are divided into zones, and for example, in the case of the central side lamp, the illuminance distribution of a mountain pattern in which the central part has a large illuminance. On the other hand, in the outer lamp, by controlling the irradiation conditions so as to obtain a valley-shaped illuminance distribution in which the outer illuminance is large, the actual illuminance obtained by combining the two is uniform in the central part and the outer part. It can be an illuminance pattern.

Next, a heat treatment apparatus according to the fourth example of the present embodiment will be described with reference to FIG.

The heat treatment apparatus 48 according to the fourth example of the present embodiment has the same basic configuration as the heat treatment apparatus 42 according to the third example of the present embodiment.

In the heat treatment apparatus 48, a plurality of convex lens portions 50a to 50n are formed in the quartz window 50 so as to face the plurality of lamps 16, respectively.
Different from 2.

In the heat treatment device 48 according to the fourth example of the present embodiment, the directivity of the lamp is improved by the action of the convex lens portion. The structure in which the quartz window has the convex lens portion can be applied to the other embodiments.

[0061]

According to the heat treatment apparatus of the present invention, the dome is divided into a heating source section in which the lamp heater is arranged and a processing section in which the object to be processed is divided, and is convexly curved toward the lamp heater side. Since the quartz window is provided in a rectangular shape, the quartz window is not deformed or damaged when the temperature is rapidly raised. Further, the central portion of the quartz window can be made thinner than the peripheral portion, and thus the irradiation efficiency can be improved.

According to the heat treatment apparatus of the present invention,
Since the quartz window is formed with a plurality of convex lens portions facing the plurality of lamps, the directivity of the lamp is improved.

According to the heat treatment apparatus of the present invention,
A peripheral portion of the reflector hangs down to provide a drooping portion, and more preferably, the drooping portion has an inclined surface that spreads toward the object to be processed, thereby improving the irradiation efficiency of the lamp.
Further, the object to be treated can be heated uniformly as a whole.

According to the heat treatment apparatus of the present invention,
The quartz window has an opaque quartz portion at its peripheral portion, and the opaque quartz portion has a reflecting surface that reflects the heat rays of the lamp heater toward the object to be processed, so that the irradiation efficiency can be improved.

According to the heat treatment apparatus of the present invention,
Since the plurality of lamps are respectively arranged in a curved shape at an equal distance from the quartz window, the directivity of the lamps in the peripheral portion can be enhanced, and the object to be processed can be uniformly heated as a whole. .

According to the heat treatment apparatus of the present invention,
In the heat treatment apparatus provided with the hanging portion, the reflector is omitted in the lamp heater except for the hanging portion, and a flat plate having the same reflectance as the reflector is provided on the back surface of the lamp, which simplifies the apparatus configuration. In addition, the device cost is low.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a heat treatment apparatus according to a first example of the present embodiment.

FIG. 2 is a graph showing an illuminance distribution when the heat treatment apparatus of FIG. 1 is used.

FIG. 3 is a schematic diagram of a heat treatment apparatus according to a second example of the present embodiment.

4 is a schematic diagram of a heat treatment apparatus according to a first modified example of the apparatus of FIG.

5 is a schematic diagram of a heat treatment apparatus according to a second modified example of the apparatus of FIG.

6 is a schematic diagram of a heat treatment apparatus according to a third modification of the apparatus of FIG.

7 is a graph showing an illuminance distribution when the heat treatment apparatus of FIG. 6 is used.

FIG. 8 is a schematic diagram of a heat treatment apparatus according to a third example of the present embodiment.

9 is a graph showing an illuminance distribution when the heat treatment apparatus of FIG. 8 is used.

FIG. 10 is a schematic diagram of a heat treatment apparatus according to a fourth example of the present embodiment.

FIG. 11 is a schematic view of a conventional heat treatment apparatus.

12 is a view of the lamp heater of the heat treatment apparatus of FIG. 11 seen from below.

13 is a graph showing an illuminance distribution when the heat treatment apparatus of FIG. 12 is used.

[Explanation of symbols]

2 Object to be treated 10, 26, 30, 34, 38, 42, 48 Heat treatment device 12, 40, 44 Lamp heater 14, 36, 50 Quartz window 16 Lamp 18, 28, 32, 46 Reflector 20 Heat source part 22 Processing part 28a, 32a, 40a Hanging part 31 Flat plate 36a Peripheral edge part 50a-50n Convex lens part

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/22 H01L 21/26 J

Claims (7)

[Claims] 1. A heat treatment apparatus for performing heat treatment on an object to be processed using a lamp heater, wherein the lamp heater includes a plurality of lamps arranged to face the object to be processed and the plurality of lamps. And a reflector provided on the back surface of the lamp heater, and a quartz window that is convexly curved toward the lamp heater is provided to partition the heating source section in which the lamp heater is arranged and the processing section in which the object to be processed is arranged. A heat treatment apparatus characterized by the following. 2. The heat treatment apparatus according to claim 1, wherein the quartz window is formed with a plurality of convex lens portions facing each of the plurality of lamps. 3. The reflector according to claim 1, wherein a peripheral portion of the reflector corresponding to a peripheral portion of the object to be processed is hung so as to be provided with a hanging portion. Heat treatment equipment. 4. The heat treatment apparatus according to claim 3, wherein the hanging portion has an inclined surface that widens toward the object to be processed. 5. The quartz window has an opaque quartz portion at a peripheral portion of the quartz window corresponding to a peripheral portion of an object to be disposed, and the opaque quartz portion receives heat rays of the lamp heater. The heat treatment apparatus according to any one of claims 1 to 4, further comprising a reflecting surface that reflects toward a body. 6. The heat treatment apparatus according to claim 1, wherein each of the plurality of lamps is arranged in a curved shape at an equal distance from the quartz window. 7. The heat treatment apparatus according to claim 3, wherein the lamp heater is configured such that the reflector is replaced by a flat plate having a reflectance equivalent to that of the reflector.