JPH04713A - Heating apparatus for substrate - Google Patents

Abstract

PURPOSE:To make an energy efficiency good and to make the temperature of a substrate uniform by a method wherein a plurality of infrared lamps are arranged in a concentric circle shape by using the shaft of a disk-shaped specimen stage as the center. CONSTITUTION:While a specimen stage 13 is being turned by using a shaft 12 as the center, infrared rays are radiated from infrared lamps 17. Thereby, a substrate 14 is heated; its temperature is measured at individual zones by using a thermocouple 22 and radiation thermometers 23. Since a plurality of infrared lamps 17 are arranged in a shape matched to the movement of the substrate 14, i.e. in a circular shape using the shaft 12 as an axis, relative positions of the infrared lamps 17 to the substrate 14 are not changed, and a stable heating operation can be executed. In addition, since the radiation intensity, i.e., the heat-generating amount of the infrared lamps 17 is fed back and controlled at individual rows, the temperature of the substrate 14 placed on the specimen stage 13 is always uniform even when a rapid heating operation is executed, and it is possible to prevent the substrate from being slipped by an uneven temperature.

Description

[Detailed Description of the Invention] The present invention relates to a substrate heating device, and more specifically, in the field of semiconductor manufacturing, it is used for heat treatment of a substrate such as a silicon wafer, or for epitaxial growth on a substrate. The present invention relates to a heating device for a substrate.

The manufacturing process of the broiled limb lid integrated circuit includes a process of heating a substrate made of a silicon wafer or the like to a high temperature, such as an annealing treatment to reduce defects caused by epitaxial growth, ion implantation, or the like. Conventionally, in this process, thermal stress occurs due to uneven heating of the board, which, combined with a decrease in the mechanical strength of the board due to high temperatures, causes defects called slipping on the board, which impairs the performance of the circuits made on the board. There was a significant decrease.

For example, in silicon epitaxial equipment, a heating lamp such as an infrared ray is used to heat the substrate to a high temperature of 100°C to 1200°C in order to cause a reaction in the raw material gas introduced into the equipment and to reduce defects in the epitaxially grown film. However, at this time, the sample stage that holds the substrate radiates heat to the surroundings, so the temperature decreases toward the periphery of the sample stage, making the temperature of the substrate uneven, which causes thermal stress.

In order to solve this problem, in recent years, various studies have been conducted to develop devices that control the radiation intensity of infrared lamps, uniformize the temperature of the substrate during heating, and suppress the occurrence of thermal stress.

For example, Japanese Unexamined Patent Publication No. 154616/1983 proposes an epitaxial device as shown in FIGS. 7 and 8. That is, in FIGS. 7 and 8, 51 is a reaction chamber having a substantially rectangular parallelepiped shape, and a discharge hole 52 and an introduction hole 53 for raw material gas are formed in the side wall of the reaction chamber, respectively. A rotatable sample stand 55 that holds a substrate 54 is provided in the reaction chamber 51, and two openings are provided in the upper part of the reaction chamber 51 with a partition bar 51b corresponding to the center position of the sample stand 55 in between. The portions 51a, 51a are formed symmetrically. Further, a transparent quartz plate 56 is pressed by a holding frame 57 on the openings 51a and 51a, and above the transparent quartz plate 56, the substrate 54 on the sample stage 55 is inserted through the transparent quartz plate 56. Multiple rod-shaped infrared lamps 5 for heating
8 are arranged in parallel at equal intervals. In addition, the infrared lamp 58
In the apparatus described above, in which a reflecting mirror 58a is disposed behind the substrate 54, when the infrared rays are irradiated from the infrared lamp 58 to the substrate 54 while rotating the sample stage 55, the partition bars 51b between the openings 51a and the presser frame 57 are exposed. The board 5 is separated by the partition bar 57a.
4, the irradiation of infrared rays is restricted, while the center part of the substrate 54
The periphery of the substrate 54 is irradiated more than the center, and as a result, the temperature of the substrate 54 can be made uniform.

Furthermore, Japanese Patent Laid-Open No. 62-93378 proposes an epitaxial device as shown in FIG. 9.

That is, in FIG. 9, reference numeral 61 is a cylindrical reaction chamber, and its side wall has a raw material gas discharge hole 52 and an introduction hole 5.
3 are formed respectively. A rotatable sample stage 55 that holds a substrate 54 is disposed inside the reaction chamber 61, and above the substrate 54, a plurality of rod-shaped infrared lamps 69a are installed.
are arranged in parallel at equal intervals, and both ends thereof penetrate the side wall of the reaction chamber 61, respectively. Further, below the sample stage 55, a plurality of rod-shaped infrared lamps 69b are arranged in parallel at equal intervals, perpendicular to the infrared lamp 69a, and both ends thereof each penetrate the side wall of the reaction chamber 61. . The inner surface of the reaction chamber 61 is coated with a material that causes diffuse reflection or a material that causes specular reflection. In this device, the infrared lamps 69a, 69b described above are divided into zones, and the infrared lamps 69a, 69b are rotated while the sample stage 55 is rotated.
By adjusting the radiation intensity of the infrared rays b for each zone, the temperature of the substrate 54 is made uniform.

However, the former problem mentioned above, JP-A-62-15461,
In the device proposed in Publication No. 6, in order to control the heating of the substrate 54, a partition bar 51b between the openings 51a and a presser frame 57 are used.
Since a part of the infrared radiation is blocked by the partition bar 57a, there is a problem that the efficiency of the thermal energy radiated from the infrared lamp 58 is reduced.

Also, this device of the former and Japanese Patent Application Laid-Open No. 62-9337 of the latter
In both the devices proposed in Publication No. 8, infrared rays are irradiated while rotating the sample stage 55 in order to uniformly heat the substrate 54 in the circumferential direction. There was a problem in that it was necessary to rotate the sample stage 55 at high speed, and technical considerations were also required for this purpose. Moreover,
Manufacturing a heating system equipped with a sample stage 55 that can rotate at high speed requires a large amount of cost, and the energy cost during use is also high.

Furthermore, in both of the above devices, rod-shaped infrared lamps 58 are arranged in parallel above and below the substrate 54 while the sample stage 55 is rotated.
...Alternatively, since infrared rays are emitted from 69a and 69b, even if the intensity of infrared rays is adjusted for each zone, the infrared lamps 5
8..., 69a, 69b are linear, the heating status of the substrate 54 by the infrared lamps 58..., 69a, 69b changes from moment to moment and is not constant. There was also the problem that temperature uniformity could not be achieved sufficiently.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a substrate heating device that can uniformize the temperature of the substrate with energy efficiency and reduce the production cost and energy cost of the heating system. .

In order to achieve the above object of Section 71, the substrate heating device according to the present invention includes a container whose surface facing the infrared lamp is formed of an infrared transparent material, and a substrate placed inside the container. 1) A substrate heating device equipped with a disc-shaped sample stage for heating the substrate, characterized in that the infrared lamps are arranged in a plurality of rows concentrically around the rotation axis of the disc-shaped specimen stage.
Further, in the apparatus of (1) above, the apparatus comprises means for measuring the temperature of the sample stage for each zone of the sample stage corresponding to each row of infrared lamps, and controls the amount of heat generated by the infrared lamps according to the measured value. It is characterized by having the means (2).

Furthermore, the apparatus of (1) or (2) above is characterized in that it is provided with a gas introduction hole and a gas exhaust hole for epitaxial vapor phase growth on the substrate (3).

■ According to the apparatus described in (1) above, since the shape of the sample stage is a disk, if the current flowing through the infrared lamps arranged concentrically in multiple rows is controlled for each row, each row Heating by the infrared lamps is energy efficient and effective for each zone of the sample stage corresponding to the infrared lamps, and the substrate placed on the disc-shaped sample stage is heated uniformly.

Further, according to the apparatus described in (2) above, the temperature of the sample stage is measured for each zone of the sample stage corresponding to each row of infrared lamps, and the heat generation amount of the infrared lamps is feedback-controlled according to the measured value. Therefore, the temperature of the substrate placed on the sample stage becomes more uniform.

Furthermore, according to the apparatus described in (3) above, a homogeneous thin film can be formed on the substrate in the container by epitaxial vapor phase growth,
Moreover, there is less slippage of the board.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a substrate heating device according to the present invention will be described below with reference to the drawings.

1 and 2 are a schematic plan view and a schematic cross-sectional view, respectively, of a substrate heating device (horizontal furnace) according to the present invention, and numeral 11 in the figure shows an upper surface formed of an infrared transmitting material such as quartz. The figure shows a substantially rectangular parallelepiped-shaped container. A rotary shaft 12 is airtightly and rotatably provided approximately at the center of the lower surface of the container 11 and passes through the container in a direction perpendicular to the container 11. A plurality of substrates 14 are mounted on the upper end of the rotary shaft 12. A disk-shaped sample stage 13 is arranged so that its fineness is the same as that of the rotating shaft 12. In addition, the sample stage 13 of the container 11
Both side walls 11a are made of stainless steel, one side wall 11a is formed with a gas introduction hole 15 for epitaxial vapor growth on the substrate 14, and the other side wall 1
A gas discharge hole 16 is formed in 1a at a position opposite to the gas introduction hole 15 with the sample stage 13 in between.

Above the container 11 is a short rod-shaped infrared lamp 1.
7 are arranged in a plurality of rows concentrically around the rotation axis 12 of the sample stage 13, and a spherical infrared lamp 17 is disposed at the center thereof. Here, the rod-shaped infrared lamp 17 used has a length of, for example, 100 mm, and a circle formed by a large number of the outermost infrared lamps 17 has a diameter of 500 mm. As shown in FIG. 3, these infrared lamps 17 are connected within the same circle by conductive wires 17a,
Conductor introduction portion 1 of each row of infrared lamps 17 shown in FIG.
7b are each connected to a PID controller (not shown).

Above the infrared lamp 17 is a support plate 18 made of stainless steel.
As shown in FIG. 5, the infrared lamps 17 are supported by the support plate 18 at a predetermined distance apart by having both ends thereof inserted into the electrode support portions 18a of the support plate 18. ing. Further, a reflecting plate 21 having a reflecting surface 21a made of parabolic gold plating is disposed on the lower surface of the support plate 18 in a portion facing the infrared lamp 17.
The reflector plate 21 improves the directivity of the infrared radiation from the infrared lamps 17, so that each zone of the substrate 14 directly under the infrared lamps 17 in each row is particularly strongly heated. A water-cooled pipe 19 is formed in the reflection plate 21 at a position corresponding to the reflection surface 21a and the reflection surface 21a, that is, at a position corresponding to between the infrared lamps 17, in order to protect the reflection surface 21a. At the top of the plate 18, there is a conducting wire 17a.
, 17b, a compressed air inlet 2° is formed for feeding compressed air for cooling between the infrared lamps 17.

On the other hand, below the container 11, a radiation thermometer 23 is arranged for each zone of the sample stage 13 corresponding to each row of infrared lamps 17, and at the center of the lower surface of the sample stage 13 is a rotation axis. A thermocouple 22 inserted from 12 is buried.

The temperature of the sample stage 13 is measured for each zone using these thermocouples 22 and radiation thermometers 23.

When heating the substrate 14 placed on the sample stage 13 using the heating device configured as described above, infrared rays are irradiated from the infrared lamp 17 while the sample stage 13 is rotated about the rotating shaft 12. As a result, the substrate 14 is heated, and its temperature is measured for each zone via the sample stage 13 using the thermocouple 22 and the radiation thermometer 23. The measured temperature information is sent to each temperature controller, and the temperature controller compares this temperature information with the target temperature input from the temperature programmer so that the temperature of each zone of the sample stage 13 becomes the target temperature. Outputs control signals to each PID controller. Then, each PID controller performs control using a thyristor based on the sent control signal to increase or decrease the current flowing through the infrared lamp 17.

Therefore, since the infrared lamps 17 are arranged in multiple rows in a shape that matches the movement of the substrate 14, that is, in a circle around the rotation axis 12, the relative position of the infrared lamps 17 with respect to the substrate 14 does not change and is stable. This makes it possible to achieve high-temperature heating. Furthermore, since the radiation intensity of the infrared lamps 17 is feedback-controlled for each row, that is, the amount of heat generated, the temperature of the substrate 14 placed on the sample stage 13 is always uniform even when rapid heating is performed. The occurrence of substrate slippage due to non-uniformity is prevented.

Further, since the gas introduction hole 15 and the gas discharge hole 16 are formed in the side wall 11a of the container 11, it is possible to form a homogeneous thin film on the substrate 14 in the container 11 by epitaxial growth.

Another embodiment of the substrate heating device according to the present invention is shown in FIG.

The apparatus shown in FIG. 6 is a vertical furnace that is circular in plan view and is used to form an epitaxial film on a substrate. The same parts of the apparatus having the same names as in FIGS. 1 and 2 are given the same numbers in FIG. 6 as in FIGS. 1 and 2, and their explanations are omitted.

In the case of a vertical furnace as well, the positional relationship between the infrared lamp 17 and the sample stage 13, the means for measuring the temperature of the sample stage 13, the means for controlling the calorific value of the infrared lamp 17 according to the measured value, etc.
It is almost the same as the model furnace shown in FIGS. 1 and 2. However, it is preferable that the gas introduction hole 15 for introducing gas for growing an epitaxial film onto the substrate 14 be provided in the rotation axis of the sample stage 13, and the gas discharge hole 16 be provided near the outer periphery of the bottom of the container 11. . This is because it is more suitable for forming a homogeneous thin film on the substrate.

In addition, in the above embodiment, when irradiating infrared rays, the sample stage 13
However, since the infrared lamps 17 arranged concentrically in multiple rows are controlled for each row, the sample stage 13 must not be rotated when irradiating the infrared rays (but the temperature of the substrate 14 may vary). Uniformity can be achieved.

Further, in the above embodiment, a plurality of rod-shaped infrared lamps 17 are arranged concentrically in a plurality of rows as the infrared lamps 17, but the invention is not limited to this, and circular or semicircular infrared lamps are arranged in each row. May be used.

As is clear from the above description, according to the substrate heating device of the present invention, infrared lamps are arranged in multiple rows concentrically around the rotation axis of the disk-shaped sample stage. Therefore, the required zone of the sample stage corresponding to the infrared lamp can be heated with energy efficiency without rotating the sample stage. In this case, the cost of the heating system associated with manufacturing the rotatable sample stage can be reduced.

In addition, if the radiation intensity of each row of infrared lamps, that is, the amount of heat generated from each row, is feedback-controlled, even if rapid heating is performed, the substrate placed on the sample stage will always be uniform and energy efficient. It can be heated well and prevents slippage due to uneven temperature.

Furthermore, if the container has gas inlet holes and gas exhaust holes, a homogeneous thin film can be formed on the substrate in the container by epitaxial growth, and there is less slippage of the substrate.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a substrate heating device (horizontal furnace) according to the present invention, and FIG. 2 is a schematic cross-sectional view of the substrate heating device. FIG. 4 is a partially enlarged sectional view showing the wire introduction part of the infrared lamp in the same circle; FIG. 5 is a partially enlarged perspective view showing the infrared lamp supported on the support plate; FIG. The figures are a schematic cross-sectional view of another substrate heating device (vertical furnace) according to the present invention, FIG. 7 is a schematic cross-sectional view showing a conventional heating device, and FIG.
The figure is a schematic plan view of FIG. 7, and FIG. 9 is a schematic cross-sectional view showing another conventional heating device. 11... Container 12... Rotating shaft 13... Sample stage 14... Substrate 15... Gas introduction hole 16
...Gas exhaust hole 17...Infrared lamp 22
... Thermocouple 23 ... Radiation thermometer

Claims (3)

[Claims] (1) In a substrate heating device comprising a container whose surface facing the infrared lamp is formed of an infrared transparent material and a disk-shaped sample stage for placing the substrate inside the container, the infrared lamp is A heating device for a substrate, characterized in that a plurality of rows are arranged concentrically around the rotation axis of the disk-shaped sample stage. (2) Claim 1, further comprising means for measuring the temperature of the sample stage for each zone of the sample stage corresponding to each different infrared lamp, and means for controlling the amount of heat generated by the infrared lamp according to the measured value. A heating device for the described substrate. (3) The substrate heating device according to claim 1 or 2, further comprising a gas introduction hole and a gas discharge hole for epitaxial vapor phase growth on the substrate.