JP2003142408A - Sheet heat treatment device and heat treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment device and a heat treatment method by which a preheated member can be prevented from being damaged and heat treatment can be appropriately conducted. SOLUTION: This heat treatment device 100 is provided with a heat treatment container 1 where a susceptor 2 on which a wafer W is placed and a preheated member 6 surrounding the outer circumference of the susceptor are arranged inside and a gas supply inlet 4 is formed, and a heater 3 to heat the wafer W that is placed on the susceptor from the outside of the heat treatment container 1. In this case, the preheated member 6 is formed like a major arc surrounding a half or larger of the outer circumference of the susceptor 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-wafer heat treatment apparatus and a heat treatment method for heat-treating silicon single crystal wafers one by one.

[0002]

2. Description of the Related Art Conventionally, a silicon single crystal wafer (hereinafter referred to as
A process for forming a thin film such as a silicon epitaxial layer or an oxide film on the main surface of the wafer), a process for etching the main surface of the wafer with a gas, and the like are performed using a heat treatment apparatus. Of these, the single-wafer type heat treatment apparatus is an apparatus for processing wafers one by one. The single-wafer heat treatment apparatus is provided with a heat treatment container formed of, for example, quartz so as to be transparent, and a susceptor for placing one wafer is provided inside the heat treatment container. A heating device composed of a halogen lamp or the like is provided around the heat treatment container so that the wafer placed on the susceptor can be heated from outside the heat treatment container. Further, a gas supply port for supplying reaction gas or the like into the heat treatment container is formed on one side of the heat treatment container, and a gas outlet for discharging gas from the heat treatment container is formed on the other side of the heat treatment container. Is formed. The heat treatment apparatus is provided with a gas supply device and the like for supplying various reaction gases and the like with a predetermined composition and flow rate from the gas supply port into the heat treatment container.

In the heat treatment by the single-wafer type heat treatment apparatus, one wafer is placed on the susceptor, the heating apparatus heats this wafer, and a reaction gas is supplied from the gas supply port. For example, a silicon source gas, a dopant gas or the like is supplied in the formation of the silicon epitaxial layer, an oxygen gas or the like in the formation of the oxide film, and a hydrogen chloride gas or the like is supplied in the etching together with the carrier gas. Then, the mixed gas of the reaction gas and the carrier gas is circulated in the gas outlet direction, so that the reaction gas flows on the wafer surface,
Various processes such as etching and thin film formation are performed on the main surface of the wafer.

In such a heat treatment process, it is desirable that the temperature of the wafer surface be kept uniform. Therefore, in the heat treatment container, a preheating member is provided so as to surround the lateral periphery of the susceptor (Japanese Patent Laid-Open No. 7-8886).
3 gazette). The preheating member is formed in a ring shape along the outer circumference of the susceptor 202, for example, like the preheating ring 206 shown in FIG. 6, and is heated together with the wafer W placed on the susceptor 202 by the heating device during the heat treatment. It is like this. The preheating ring 206 prevents the temperature of the peripheral portion of the wafer W from becoming lower than the temperature of the central portion of the wafer W due to the influence of the sidewall of the heat treatment container having a relatively low temperature. Further, the gas supplied into the heat treatment container is heated to a temperature suitable for heat treatment such as reaction by flowing over the preheating member 206 until the gas reaches the wafer from the gas supply port, so that the wafer W is appropriately heat treated. It is supposed to be done.

[0005]

Since the preheating ring 206 has a large temperature difference between the inside (susceptor side) and the outside (side wall of the heat treatment container), a difference in thermal expansion occurs and a high thermal stress is applied. . As a result, the preheating ring 206 may crack and break during processing. In such a case, if particles (fine particles) or the like caused by the damage adhere to the wafer, the yield of the product will be reduced. Further, when replacing the damaged preheating ring 206, it is necessary to stop the heat treatment apparatus, which is also inconvenient because there is a problem that the operating rate of the apparatus decreases.

An object of the present invention is to provide a single-wafer type heat treatment apparatus and a heat treatment method capable of preventing the preheating member from being damaged or the like and suitably performing heat treatment.

[0007]

In order to solve the above problems, the first means according to the present invention mounts a [1] substrate (for example, a silicon single crystal wafer W) as shown in FIGS. A susceptor (2) to be placed and a preheating member (6) provided along the outer periphery of the susceptor at the side of the susceptor are arranged inside, and a gas supply port (4) for taking in gas from the outside is provided. A single-wafer heat treatment apparatus (heat treatment) that includes a formed heat treatment container (1) and [2] a heating device (3) that heats a substrate placed on the susceptor from outside the heat treatment container. The apparatus 100) is characterized in that the preheating member (6) is formed in an arc shape along the outer circumference on the side of the susceptor.

According to the first means, the preheating member is formed in an arc shape. That is, the preheating member surrounds the outer circumference on the side of the susceptor and is formed in a shape in which a part of the circumference is missing. Therefore, when a temperature difference occurs between the inner portion and the outer portion of the preheating member, the preheating member can be easily deformed, so that the thermal stress is eliminated. Therefore, it is possible to prevent the preheating member from being damaged by the thermal stress, so that it is possible to suppress a decrease in the yield and a decrease in the operating rate of the heat treatment apparatus, which are caused by the damage to the preheating member. It is preferable that the preheating member is provided on the upstream side of the gas on the outer circumference of the susceptor (that is, in the preheating member having a shape in which a part of the circumference is missing, the missing portion is provided on the downstream side of the gas). This is because it is possible to prevent the effect that the preheating member heats the gas flowing onto the wafer W on the upstream side from being impaired.

A second means according to the present invention is characterized in that, in the single-wafer heat treatment apparatus of the first means, the preheating member (6) is formed in a superior arc shape.

According to the second means, the preheating member is formed in a superior arc shape (that is, the outer circumference on the side of the susceptor is surrounded by more than half circumference). Therefore, the same effect as the heat treatment apparatus of the first means can be obtained, and the original function of the preheating member (the function of preventing the ambient temperature of the substrate from becoming lower than the center of the substrate, and the gas supplied) The function of heating the substrate can be exerted, so that the substrate can be suitably heat-treated.

A third means is the single-wafer heat treatment apparatus of the first means, wherein the preheating member (6) is composed of a plurality of inferior arc members. According to the third means, since the preheating member is composed of a plurality of inferior arc-shaped members, the outer circumference on the side of the susceptor is surrounded by more than half the circumference, so that the same effect as the second means can be obtained.

The fourth means according to the present invention is [1] a susceptor (2) on which a substrate is placed, and a preheating member (6) provided on the side of the susceptor along the outer periphery of the susceptor.
And a heat treatment container (1) in which a gas supply port (4) for taking in gas from the outside is formed,
[2] In a single-wafer heat treatment apparatus provided with a heating device (3) for heating a substrate placed on the susceptor from the outside of the heat treatment container, the preheating member (6) is
It is characterized in that it is formed in a shape that surrounds the periphery of the susceptor in a spiral shape or a spiral shape.

According to the fourth means, since the preheating member has a shape that surrounds the periphery of the susceptor in a spiral shape or a spiral shape,
Even if a temperature difference occurs between the inside and the outside of the preheating member, the preheating member can be easily deformed to eliminate the thermal stress. Therefore, it is possible to exhibit the original function of the preheating member as described above and prevent the preheating member from being damaged by thermal stress, and thus it is possible to obtain the same effect as that of the heat treatment apparatus of the first to third means. .

The fifth means according to the present invention is defined in claim 1.
In the single-wafer heat treatment apparatus according to any one of 1 to 4, the preheating member is placed on a pedestal (7) arranged in the reaction device, and the preheating member and the pedestal are provided with a guide mechanism. (For example, the protrusion 16c and the guide groove 17a) are provided.

In this guide mechanism, when the shape of the preheating member changes in accordance with the temperature change in the heat treatment container during the heat treatment, the relative positional relationship of the preheating member to the susceptor is within a range suitable for performing the heat treatment. It guides the mounting position of the preheating member with respect to the pedestal so as to be maintained inside. In the heat treatment process, the preheating member is deformed due to the temperature rise and temperature fall in the heat treatment container,
This is because if the mounting position of the preheating member on the pedestal shifts and the position of the preheating member shifts with respect to the susceptor, there is a risk that the temperature around the wafer mounted on the susceptor becomes non-uniform. Therefore, according to the fifth means, even if the shape of the preheating member changes, the position of the preheating member with respect to the susceptor can be maintained at a position suitable for heat treatment.

A sixth means according to the present invention is to mount a silicon single crystal wafer on a susceptor in the single-wafer heat treatment apparatus according to any one of the first to fifth aspects of the present invention and This is a heat treatment method characterized in that a vapor phase growth of a thin film is performed on the surface.

According to the heat treatment method of the sixth means, it is possible to prevent the preheating member from being damaged by heating in the vapor phase growth process of the thin film, so that the fine particles generated by the damage adhere to the silicon single crystal wafer. Can be prevented. It is also possible to prevent the heat treatment apparatus from being stopped for replacing the preheating member. Therefore, a decrease in product yield can be reduced, and a decrease in operating rate of the heat treatment apparatus can be suppressed, so that productivity is improved.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 shows an example of a single-wafer heat treatment apparatus 100. The heat treatment apparatus 100 is an apparatus that performs a process involving heating, such as vapor phase epitaxial growth and formation of an oxide film, one by one on the main surface of a substrate such as a silicon single crystal wafer.

The heat treatment apparatus 100 is provided with a heat treatment container 1 for performing a heat treatment on the wafer W. The top wall 1a and the bottom wall 1b of the heat treatment container 1 are made of transparent quartz. Inside the heat treatment container 1, a susceptor 2 whose base is made of graphite is provided. A counterbore for mounting the wafer W in a substantially horizontal direction is formed on the upper surface of the susceptor 2, and can be rotated in the circumferential direction by a motor (not shown) or the like. A heating device 3 including a halogen lamp and the like is provided above and below the heat treatment container 1.

A gas supply port 4 for supplying a reaction gas into the heat treatment container 1 is formed on one side of the heat treatment container 1, and a gas is discharged from the heat treatment container 1 on the other side of the heat treatment container 1. A gas discharge port 5 is formed. Further, the heat treatment apparatus 100 is equipped with a gas supply device (not shown) for supplying various reaction gases and the like into the heat treatment container 1 at a predetermined composition and flow rate, and a gas supply extending from the gas supply device. The tube is the gas supply port 4 of the heat treatment container 1.
It is designed to be connected to.

In the heat treatment container 1, a preheating member 6 whose base is made of graphite is provided so as to surround the lateral periphery of the susceptor 2. The preheating member 6 is an arc-shaped plate, and as shown in FIG.
It is formed in the shape of a letter (the shape of a superior arc). Further, on the lower surface of the preheating member 6, leg portions 6a extending downward along the outer periphery (FIG. 2)
Are formed. When the preheating member 6 is provided in the reaction container 1, as shown in FIG. 1, the leg portion 6a is placed on a pedestal 7 provided on the side of the susceptor 2 so as to be in contact therewith. .

The preheating member 6 is heated together with the wafer W by the heating device 3 as will be described later in a state of enclosing the lateral periphery of the susceptor 2. Thereby, the influence of the side wall portion of the heat treatment container 1 having a lower temperature than the central portion of the susceptor is reduced, and the peripheral portion of the wafer W is prevented from having a lower temperature than the central portion of the wafer. It also has a function of increasing the temperature of the gas supplied from the gas supply port 4 until it reaches the wafer W, and heating it to a temperature suitable for heat treatment. In order for the preheating member 6 to effectively exhibit these functions, it is desirable to surround the outer circumference of the susceptor 2 by a half or more. Further, in order not to impair the function of heating the gas, it is preferable to mount the preheating member 6 so that the defective portion 6b (FIG. 2) is located on the downstream side of the gas.

A heat treatment method by the heat treatment apparatus 100 will be described. First, while the wafer W (not shown) is placed on the susceptor 2 in the heat treatment container 1, the susceptor 2 is rotated in the circumferential direction, and the heating device 3 brings the wafer W and the preheating member 6 to a predetermined temperature. To heat. Then, the reaction gas is circulated from the gas supply port 4 side toward the gas discharge port 5 at a predetermined flow rate and composition so that the gas flows on the surface of the wafer W. For example, in the case of forming a silicon epitaxial layer, a silicon source gas (for example, dichlorosilane, trichlorosilane, etc.) or a dopant gas, in the case of forming an oxide film, oxygen gas or the like, and in etching, hydrogen chloride gas or the like, It is supplied onto a heated wafer together with a carrier gas such as hydrogen gas. A thin film such as a silicon epitaxial layer or an oxide film is formed and etched on the main surface of the wafer W by the mixed gas of the reaction gas and the carrier gas. The heating temperature, the composition and flow rate of the gas to be circulated, the circulation time and the like are appropriately set for each process, such as desired thin film characteristics and thickness, or etching thickness in the case of etching.

In the heat treatment process, since the temperature of the outside of the preheating member 6 on the side wall side of the reaction vessel 1 is lower than that of the inside of the preheating member 6 provided with the susceptor 2, there is a difference in thermal expansion of the preheating member 6. Occurs. However, as described above, since the preheating member 6 is formed in a C shape, the preheating member 6 is deformed so that the defective portion 6a is opened, and is deformed according to the temperature difference between the inside and the outside. Further, even if the heating temperature of the wafer W is lowered after the heat treatment, the preheating member 6 is easily deformed according to the temperature difference between the inside and the outside, such as returning to the shape before heating.

According to the heat treatment apparatus 100 described above, the preheating member 6 has a shape (C-shape) in which a part of the circumference is lost.
In the heat treatment process for the wafer W placed in the reaction container 1, the wafer W can be easily deformed even if a temperature difference occurs between the inside and the outside of the preheating member 6. Therefore, even if thermal stress is applied to the preheating member 6 due to the temperature difference between the inner side (the susceptor 2 side) and the outer side (the side wall side of the reaction vessel 1) in the heat treatment, the preheating member 6 is eliminated by the deformation, so that the preheating member 6 is exposed to the thermal stress. It can be prevented from being damaged. In addition, the preheating member 6
Is a C-shape that surrounds the lateral outer periphery of the susceptor 2 for more than half the circumference, and therefore, when heated together with the wafer W, the temperature of the periphery of the wafer W is lower than that of the inside. Therefore, it is possible to prevent the temperature from going down, and it is possible to exhibit the original function of heating the gas supplied from the gas supply port 4 before reaching the wafer W and suitably performing the heat treatment.

In the present embodiment, the preheating member 6
Although it has a C-shaped superior arc shape, it may have a U-shape, or may have a shape in which a notch is formed at one position of the preheating member as shown in FIG. Further, as shown in FIG. 3B, the cut may be formed in an oblique direction with respect to the radial direction. Further, as shown in FIG. 3 (c), the preheating member 6 may have a shape in which a part of the circumference is notched, and the ends thereof may overlap each other. Further, the preheating member 6 may be formed so as to draw a spiral in the vertical direction of the circumference. Good. Alternatively, as shown in FIGS. 3D and 3E, the susceptor may have a spiral surrounding shape. In addition, as shown in FIG. 3F, the preheating member may be composed of a plurality of members (a plurality of inferior arc-shaped members) surrounding the periphery of the susceptor. Even with these shapes, the preheating member 6 can be easily deformed according to the temperature difference between the inside and the outside,
Further, since it has a shape that surrounds the periphery of the susceptor, the same effect as that of the C-shape described above can be exhibited. Further, the preheating member is not limited to a substantially circular shape as long as it has a shape surrounding the susceptor, and the lateral outer periphery may be formed in a quadrangular shape or the like, which can be changed.

[Second Embodiment] A top view of a preheating member 16 according to a second embodiment is shown in FIG. 4 (a), a side sectional view is shown in FIG. 4 (b), and a top view of a pedestal 17 is shown. 5 (a), a side sectional view is shown in FIG. 5 (b). The heat treatment apparatus and the heat treatment method according to the second embodiment are the same as those in the first embodiment except for the preheating member 16 and the pedestal 17, and the description thereof will be omitted.

As shown in FIG. 4, the preheating member 16 in this embodiment is similar to the first embodiment in that the susceptor 2 is used.
It has a semi-circular shape (C-shaped) that surrounds the circumference of a half or more, has leg portions 16a on the lower surface, and further has projections 16c protruding downward from the leg portions 16a at three locations. Protrusion 1
For example, as shown in FIG. 4, the portion where 6c is formed is one portion (first protrusion 16ca) on the opposite side to the defective portion 16b of the preheating member 16, and the defective portion 16b and the first protrusion 1.
6ca two half circumferences (preheating member 16 in FIG. 4
The upper half of the circumference and the lower half of the circumference are provided at one place each (second protrusion 16cb, third protrusion 16cc).
As shown in FIG. 4, the second protrusion 16cc and the third protrusion 16cc are formed from the first protrusion 16ca toward the center F direction of the preheating member 16 and from the second protrusion 16cb or the third protrusion 16cc toward the center F direction. The angle may be about 90 degrees, but 120
It may be a degree.

As shown in FIG. 5, the pedestal 17 has grooves 17aa, 17a which can be engaged with the first projection 16ca, the second projection 16cb, and the third projection 16cc of the preheating member 16, respectively.
b and 17ac (these are collectively referred to as groove 17a) are formed. The protrusion 16c and the groove 17a are combined to form a guide mechanism. The guide mechanisms 16c and 17a include the pedestal 17
When the preheating member 16 placed thereon is deformed due to the temperature change in the heat treatment process, the protrusion 16c is deformed in the state of being engaged with the groove 17a, so that the position of the preheating member 16 with respect to the susceptor 2 is predetermined. Guide so that it does not fall out of the range.

Regarding the position of the preheating member 16 with respect to the susceptor 2, the predetermined range is a range that does not interfere with the heat treatment performed on the wafer W placed on the susceptor 2, and is, for example, the center position of the susceptor 2. The state where the center position of the preheating member 16 substantially coincides is maintained, or the susceptor 2
It is preferable that the distance from the preheating member 16 to the preheating member 16 is maintained substantially uniform over the circumference. Preheating member 1
When 6 is deformed and the mounting position on the pedestal 17 is displaced so that the distance from the susceptor 2 to the preheating member 16 becomes non-uniform over the circumference, at a position where the susceptor 2 and the preheating member 16 are close to each other, This is because the temperature becomes higher than that at a distant place, and the in-plane temperature distribution on the wafer W mounted on the susceptor 2 becomes uneven. Then, if the in-plane temperature distribution of the wafer W is non-uniform, it is expected that problems such as unevenness in the thin film growth rate will occur during the heat treatment.

According to the heat treatment apparatus of this embodiment, the preheating member 16 has the same effect as the preheating member 6 of the first embodiment, and the preheating member 16 and the pedestal 17 are provided with the guide mechanism. Therefore, even if the preheating member 16 is deformed during the heat treatment, the preheating member 1 for the susceptor 2 is
The position of 6 is maintained within a predetermined range. Therefore, for example, when the preheating member 16 is deformed by the heat treatment and then returned to the shape before the deformation by the end of the heat treatment, the preheating member 16 can be returned to substantially the same position as the position placed before the heat treatment by the guide mechanism. Therefore, even if the heat treatment is repeatedly performed and the preheating member 16 is repeatedly deformed, the preheating member 16 is not displaced with respect to the susceptor 2 so as to affect the heat treatment, and the heat treatment can be suitably performed.

The present invention is not limited to the above embodiment. For example, the guide mechanism of the present embodiment can be applied not only to the C-shaped preheating member but also to various shapes of preheating members shown in FIG. 3, for example.
Further, the design of the groove can be appropriately changed within a range in which the preheating member can be appropriately guided in the deformation of the preheating member during heat treatment. For example, the groove may be formed wider toward the outer side in the radial direction. Furthermore, the number of protrusions and grooves is not limited to three, and the location of the guide mechanism can be changed in design within the predetermined range. In addition, the guide mechanism may be formed with a groove on the preheating member and a protrusion on the pedestal, and changes such as forming ribs instead of grooves are possible.

[0033]

According to the first and fourth means, when the temperature difference occurs between the inner portion and the outer portion of the preheating member, the preheating member can be easily deformed, so that the thermal stress is eliminated. It Therefore, since it is possible to prevent the preheating member from being damaged by the thermal stress, it is possible to reduce a decrease in the yield of the substrate subjected to the heat treatment, and it is possible to suppress a decrease in the operating rate of the heat treatment apparatus.

According to the heat treatment apparatus of the second and third means, the preheating member surrounds the outer circumference on the side of the susceptor by more than half the circumference, so that the preheating member has its original function (prevents the temperature decrease around the substrate and is supplied). It is possible to prevent the preheating member from being damaged by the temperature difference between the inner side and the outer side while exerting the effect of heating the gas). Therefore, the heat treatment can be suitably performed on the substrate.

According to the fifth means, even if the shape of the preheating member changes, the position of the preheating member with respect to the susceptor can be maintained at a position suitable for heat treatment.

According to the heat treatment method of the sixth means, vapor phase growth of a thin film can be carried out while preventing the preheating member from being damaged by thermal stress. Therefore, fine particles generated by the damage adhere to the silicon single crystal wafer. Can be reduced. It is also possible to prevent the heat treatment apparatus from being stopped for replacing the preheating member. Therefore, a decrease in product yield can be reduced, and a decrease in operating rate of the heat treatment apparatus can be suppressed, so that productivity is improved.

[Brief description of drawings]

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

2A and 2B show an example of a preheating member provided in the heat treatment apparatus of FIG. 1, where FIG. 2A is a top view and FIG. 2B is a side sectional view.

FIG. 3 shows another example of the preheating member provided in the heat treatment apparatus, and (a), (b), (d) to (f) are top views, (c).
Is a perspective view.

FIG. 4 shows an example of a preheating member provided in a heat treatment apparatus according to a second embodiment of the present invention, (a) is a top view,
(B) is a side sectional view.

5A and 5B show an example of a pedestal provided in the heat treatment apparatus according to the second embodiment, FIG. 5A is a top view, and FIG. 5B is a side sectional view.

FIG. 6 is a top view showing a preheating member provided in a conventional heat treatment apparatus.

[Explanation of symbols]

1 heat treatment container 2 susceptor 3 heating devices 4 gas supply port 6,16 Preheating member 16c protrusion (guide mechanism) 7,17 pedestal 17a Guide groove (guide mechanism) 100 Heat treatment equipment (single wafer heat treatment equipment)

Claims (6)

[Claims] 1. A susceptor on which a substrate is placed and a preheating member provided on the side of the susceptor along the outer periphery of the susceptor are arranged inside, and a gas supply port for taking in gas from the outside is formed. And a heating device for heating a substrate placed on the susceptor from the outside of the heat treatment container, wherein the preheating member is provided on the side of the susceptor. A single-wafer heat treatment apparatus, which is formed in an arc shape along the outer periphery. 2. The single-wafer heat treatment apparatus according to claim 1, wherein the preheating member is formed in an arc shape. 3. The single-wafer heat treatment apparatus according to claim 1, wherein the preheating member is composed of a plurality of inferior arc-shaped members. 4. A susceptor on which a substrate is placed and a preheating member provided on the side of the susceptor along the outer circumference of the susceptor are arranged inside, and a gas supply port for taking in gas from the outside is formed. And a heating device for heating a substrate placed on the susceptor from the outside of the heat treatment container, wherein the preheating member surrounds the susceptor. A single-wafer heat treatment apparatus, which is formed in a spiral or spiral shape. 5. The preheating member is mounted on a pedestal arranged in the reactor, and the preheating member and the pedestal are provided with a guide mechanism. The single-wafer heat treatment apparatus according to any one of to 4. 6. A silicon single crystal wafer is placed on a susceptor in the single-wafer heat treatment apparatus according to claim 1, and a vapor phase growth of a thin film is performed on the main surface of the silicon single crystal wafer. A heat treatment method comprising: