JP6210382B2 - Epitaxial growth equipment - Google Patents

Description

  The present invention relates to an epitaxial growth apparatus for growing an epitaxial layer on a main surface of a silicon single crystal substrate.

  As a device for growing an epitaxial layer on the main surface of a silicon single crystal substrate, a single wafer type epitaxial growth device using a vapor phase growth device as shown in Patent Documents 1 to 4 is known.

  Since the growth rate of the epitaxial layer is strongly influenced by the temperature, it is important to control the temperature distribution in the plane of the silicon single crystal substrate in order to improve the uniformity of the epitaxial layer thickness. There are various heating methods for the epitaxial growth apparatus, and in the case of a single wafer epitaxial apparatus in which a single crystal silicon substrate is epitaxially grown one by one, a heating method using a bar heater from above and below the silicon single crystal substrate is often used. In the case of the method of heating with the rod heater, the rod heaters are arranged in a circular pattern in a radial pattern, and the heat rays from the rod heater are reflected behind the rod heater to irradiate the substrate. Place a donut-shaped reflector.

  An epitaxial growth apparatus for growing an epitaxial layer on the main surface of a silicon single crystal substrate placed horizontally on a susceptor is divided into a heater group of rod heaters that heat a central region and a peripheral region of the susceptor and the silicon single crystal substrate. Some heater modules have a heater group of rod heaters that heat an intermediate region between a central region and a peripheral region, and the temperature distribution of the wafer is controlled by adjusting the output of these heater groups.

  A halogen lamp is mainly used for these bar heaters. When the temperature distribution of the wafer is made uniform, the rate of change of the energy supply distribution of each heater group is important. For example, in the case of a heater module having two heater groups for heating the central region and the peripheral region of the silicon single crystal substrate, the energy supply amount is reduced in the peripheral region in the central region heater group, and the central region in the peripheral region heater group. As the energy supply amount is reduced, the heater installation position, the number of heaters, and the reflector shape must be designed so that the rate of change of each energy supply amount is inversely correlated.

  FIG. 3 shows a conventional epitaxial growth apparatus. In FIG. 3, reference numeral 100 denotes a conventional epitaxial growth apparatus. In the epitaxial growth apparatus 100, a susceptor 104 for horizontally arranging the silicon single crystal substrate W is provided in a reaction chamber 102. The susceptor 104 is supported by a support shaft 106, and the support shaft 106 is used for rotating the susceptor 104. It has a mechanism (not shown).

In the epitaxial growth apparatus 100 shown in FIG. 3, a plurality of bar heaters 110 a and 110 b in which a plurality of rod heaters 108 are radially arranged below the susceptor 104 and a plurality of rod heaters 108 radially above the susceptor 104. A heater module 112 having a radial upper heater group 110c arranged in a circle is provided.
In the heater module 112, a radial lower heater group 110a is radially arranged for the central area, and rod-shaped heaters 108 are arranged in a circular shape, and the radial lower heater group 110b is used for the peripheral area outside the radial lower heater group 110a for the central area. The rod heaters 108 are arranged concentrically with each other.

  A cylindrical outermost peripheral reflecting member 114 is provided so as to surround the radial lower heater group 110b for the surrounding area, and further between the radial lower heater group 110a for the central area and the radial lower heater group 110b for the surrounding area. In addition, a cylindrical intermediate reflecting member 116 is installed, and in addition, a cylindrical innermost reflecting member 118 is installed inside the central area heater group 110a. Furthermore, a bar heater 108 is concentrically arranged as a radial upper heater group 110c above the susceptor 104, and a cylindrical outermost reflecting member 120 is installed so as to surround the radial upper heater group 110c. A cylindrical inner reflection member 122 is installed inside the heater group 110c. The radial upper heater group 110c is configured to supply energy uniformly from above.

  In the case of the conventional epitaxial growth apparatus 100, compared with the rate of change in the amount of energy supplied from the central region to the peripheral region of the radial lower heater group 110a for the central region, the peripheral region to the central region of the radial lower heater group 110b for the peripheral region The rate of change in the amount of energy supplied to the region may be small, and even if the output of the heater group for the central region and the peripheral region is adjusted, a high temperature region remains in the central region of the silicon single crystal substrate W. was there. When the epitaxial layer is grown on the main surface of the silicon single crystal substrate with such a temperature distribution, the epitaxial layer in the central region of the silicon single crystal substrate W becomes relatively thick, and the flatness of the silicon single crystal substrate is deteriorated. There was a problem that.

JP 2013-110145 A Special Table 2002-529911 JP 2011-146537 JP-A-4-55214

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an epitaxial growth apparatus that improves the temperature distribution uniformity of a silicon single crystal substrate and enables higher planar epitaxial growth. .

In order to solve the above problems, an epitaxial growth apparatus of the present invention is an epitaxial growth apparatus for growing an epitaxial layer on the main surface of a silicon single crystal substrate placed horizontally on a susceptor, and is located below the susceptor. A heater module having a plurality of radial lower heater groups in which a plurality of radial lower heater groups in which a plurality of rod heaters are arranged radially in a circle are arranged in two or more rows concentrically, and an outermost radial shape of the plurality of radial lower heater groups A cylindrical outermost lower reflection member surrounding the lower heater group, the outermost lower reflection member having an inclined surface, and the cylindrical outermost lower reflection as the distance from the outermost radial lower heater group increases. the inclined surface is formed so that the diameter of the member is increased, and the inclined surface is formed on the edge of the outermost lower reflector member, the outermost Between the radial lower heater group adjacent to the radially lower heater the outermost radial lower heater group with a group on the side, a cylindrical intermediate reflective member, wherein said rod-like heater is a halogen lamp.

  It is preferable that the inclined surface is formed at an edge of the outermost peripheral lower reflecting member.

  It is preferable that a cylindrical intermediate reflecting member is provided between the outermost radial lower heater group and the radial lower heater group adjacent to the outermost radial lower heater group.

  The rod heater is preferably a halogen lamp.

  As described above, an inclined surface is provided at an edge of the inner cylindrical surface of the cylindrical outermost lower reflection member installed so as to surround the radially lower heater group disposed on the outermost side, and this inclined surface is the outermost surface. It is set as the shape which the diameter of an outermost periphery downward reflection member increases, so that it leaves | separates from an outer radial lower heater group. Of the energy radiated from the outermost radial lower heater group, most of the energy is reflected multiple times between the outermost reflecting member and the intermediate reflecting member, and finally reflected by the outermost reflecting member to reach the central region. And those that are reflected by the intermediate reflecting member and reach the surrounding area.

  The energy supplied to the central region by changing the direction of energy toward the central region by providing an inclined surface that increases the diameter of the lower outermost reflective member as the distance from the heater increases at the edge of the inner cylindrical surface of the outermost reflective member. The amount can be reduced. By using such an outermost peripheral reflection member, the rate of change in the amount of energy supplied from the peripheral region to the central region of the peripheral region heater group is increased, and the energy from the central region to the peripheral region of the central region heater group is increased. By adjusting so as to have an inverse correlation with the rate of change of the supply amount, the temperature distribution uniformity of the wafer is improved, and a higher flat epitaxial growth becomes possible.

  On the other hand, even when the inclined surface at the edge of the inner cylindrical surface of the outermost peripheral reflection member has a shape in which the diameter decreases with increasing distance from the heater, the amount of energy supplied to the central region can be reduced. This is because multiple reflections are made between the outermost reflecting member and the intermediate reflecting member, and finally reflected by the outermost reflecting member, it does not go to the central region but between the outer reflecting member and the intermediate reflecting member. This is because the energy component returned to (2) increases and this energy component again undergoes multiple reflection. However, the number of multiple reflections is greatly increased, and part of the energy is absorbed by the reflecting member, which sometimes breaks the gold coat of the reflecting member. Therefore, the energy distribution can be adjusted more efficiently if the diameter increases as the distance from the heater increases.

  According to the present invention, the temperature distribution uniformity of the silicon single crystal substrate is improved, and there is a remarkable effect that it is possible to provide an epitaxial growth apparatus that enables higher planar epitaxial growth.

It is a principal part schematic diagram which shows one embodiment of the epitaxial growth apparatus which concerns on this invention. It is a graph which shows the wafer surface temperature distribution in an Example and a comparative example. It is a principal part schematic of the conventional epitaxial growth apparatus.

  In the following, one embodiment of the present invention will be described with reference to the accompanying drawings. However, it is needless to say that these descriptions are given by way of example and should not be construed as limiting.

  In FIG. 1, reference numeral 10 indicates one embodiment of an epitaxial growth apparatus according to the present invention. The epitaxial growth apparatus 10 is provided with a susceptor 14 for horizontally arranging a silicon single crystal substrate W in a reaction chamber 12, and the susceptor 14 is supported by a support shaft 16, and the support shaft 16 is used for rotating the susceptor 14. It has a mechanism (not shown).

In the epitaxial growth apparatus 10 shown in FIG. 1, a plurality of rod-shaped heaters 20 a and 20 b in which a plurality of rod-shaped heaters 18 are radially arranged below the susceptor 14 and a plurality of rod-shaped heaters 18 are arranged radially above the susceptor 14. A heater module 22 having a radial upper heater group 20c arranged in a circle is provided.
The heater module 22 has a radial lower heater group 20a arranged radially in a circular shape for the central area, and rod-shaped heaters 18 arranged radially, and a radial lower heater group 20b is arranged outside the central area radial lower heater group 20a for the peripheral area. The rod heaters 18 are arranged concentrically with each other. An example of a halogen lamp is shown as the bar heater.

  A cylindrical outermost peripheral reflection member 24 is provided so as to surround the radial lower heater group 20b for the surrounding area, and further between the radial lower heater group 20a for the central area and the radial lower heater group 20b for the peripheral area. In addition, a cylindrical intermediate reflecting member 26 is installed, and in addition, a cylindrical innermost reflecting member 28 is installed inside the central region heater group 20a. Further, a bar heater 18 is arranged concentrically as a radial upper heater group 20c above the susceptor 14, and a cylindrical outermost reflecting member 30 is installed so as to surround the radial upper heater group 20c. A cylindrical inner reflection member 32 is installed inside the heater group 20c.

  The outermost outer periphery lower reflecting member 24 has an inclined surface 34, and the diameter of the cylindrical outermost outer periphery lower reflecting member 24 increases as the inclined surface 34 moves away from the outermost radial lower heater group 20 b. It is formed to increase. The inclined surface 34 is formed on the edge 36 of the outermost periphery lower reflecting member 24.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples, and various modifications can be made without departing from the technical idea of the present invention. Of course.

Example 1
As Example 1, using the single wafer epitaxial growth apparatus for a 300 mm diameter wafer shown in FIG. A halogen lamp was used as the rod heater. The measurement was performed by the method described in Japanese Patent Publication No. 07-058730. In this method, a diffusion wafer having an impurity injection layer formed on the surface by ion implantation is prepared, and the in-plane temperature distribution of the wafer is obtained by measuring the sheet resistance after thermal diffusion. In Example 1, the angle A of the inclined surface 34 of the outermost periphery lower reflecting member 24 shown in FIG. 1 was 15 degrees, and the length H of the inclined surface 34 was 50 mm. The measurement results are shown in FIG. As shown in FIG. 2, the in-plane maximum temperature difference of Example 1 was 1.6 ° C.

(Comparative Example 1)
As Comparative Example 1, the wafer surface temperature distribution when the center temperature of the silicon wafer is heated to 1100 ° C. using the conventional single wafer epitaxial growth apparatus 100 for a 300 mm diameter wafer shown in FIG. Measured. A halogen lamp was used as the rod heater. The conventional single-wafer epitaxial growth apparatus 100 has the same configuration as the single-wafer epitaxial growth apparatus 10 of FIG. 1 except that the inclined surface 34 of FIG. 1 is not formed. The measurement result of Comparative Example 1 is shown in FIG. As shown in FIG. 2, the in-plane maximum temperature difference of Comparative Example 1 was 7.0 ° C.

  Thus, it has been shown that by using the epitaxial growth apparatus of the present invention, the temperature distribution uniformity of the silicon single crystal substrate is improved, and higher planar epitaxial growth is possible.

  The above-described embodiment is an exemplification, and the embodiment having substantially the same configuration as the technical idea described in the claims of the present invention and having the same function and effect is any type. Are also included in the technical scope of the present invention.

10: epitaxial growth apparatus of the present invention, 12, 102: reaction chamber, 14, 104: susceptor, 16, 106: support shaft, 18, 108: rod heater, 20a, 20b, 110a, 110b: radial lower heater group, 20c, 110c: radial upper heater group, 22, 112: heater module, 24, 30, 114, 120: outermost reflecting member, 26, 116: intermediate reflecting member, 28, 118: innermost reflecting member, 32, 122: inner Circumferential reflection member, 34: inclined surface, 36: edge, 100: conventional epitaxial growth apparatus, A: angle of inclined surface, H: length of inclined surface, W: silicon single crystal substrate.

Claims (1)

An epitaxial growth apparatus for growing an epitaxial layer on a main surface of a silicon single crystal substrate placed horizontally on a susceptor,
A heater module having a plurality of radial lower heater groups, which are located below the susceptor and in which two or more radial lower heater groups in which a plurality of rod heaters are arranged in a radial pattern are concentrically arranged;
A cylindrical outermost lower reflection member surrounding the outermost radial lower heater group of the plurality of radial lower heater groups;
Including
The outermost lower reflection member has an inclined surface, said inclined surface so that the diameter increases the outermost lower reflecting member of said cylindrical increasing distance from the outermost radial lower heater group is formed, and the inclined A cylindrical intermediate reflecting member is formed between the outermost radial lower heater group and the radial lower heater group adjacent to the outermost radial lower heater group. An epitaxial growth apparatus characterized in that the rod heater is a halogen lamp .

Images