JP7209675B2 - Film formation method by epitaxial growth and epitaxial growth apparatus - Google Patents

Description

The present invention relates to a film formation method by epitaxial growth and an epitaxial growth apparatus.

Conventionally, an epitaxial growth apparatus for growing an epitaxial film on a substrate by epitaxial growth includes a processing chamber and a rotatable substrate support arranged in the processing chamber and configured to rotate the substrate about a rotation axis. There is known an apparatus for forming a film on a substrate on a substrate support by introducing a reaction gas horizontally to the substrate (for example,
Patent document 1).

Japanese Patent Publication No. 2001-520456

Such an epitaxial growth apparatus is currently required to increase the growth rate. However, it is not preferable to contain a large amount of raw material gas in the reaction gas in order to increase the growth rate, because it leads to, for example, an increase in film formation cost and an increase in particles.

In epitaxial growth, the boundary layer on the substrate surface (99% of the flow velocity of the main flow of the reaction gas
It is known that the growth rate is expected to be increased by thinning the thickness at the position where the flow velocity of . On the other hand, if the thickness of the boundary layer is simply reduced, a flow in which the reaction gas escapes toward the periphery of the substrate is generated on the substrate surface, making it difficult to adjust the film thickness distribution and the resistivity distribution.

The present invention has been made in view of the above circumstances.
Another object of the present invention is to provide an epitaxial growth apparatus.

The film formation method by epitaxial growth of the present invention is performed in a reaction chamber having a top surface, a bottom surface, and a side surface defined by a ceiling plate, a substrate mounting portion (susceptor) on which a substrate is placed horizontally, and side walls, respectively. done. Here, the ceiling panel is supported at the peripheral edge of the ceiling panel from above and outside the peripheral edge. This method comprises the steps of: heating the inside of the reaction chamber to a predetermined growth temperature; , the step of rectifying the reaction gas so as to match the horizontal component in the direction from the center of the reaction chamber side opening of the reaction gas supply passage toward the center of the reaction chamber; a step of horizontally introducing the rectified reaction gas into the reaction chamber; a step of forming a film with a reactive gas;
and discharging the reaction gas after the film formation to a gas discharge passage provided at a position facing the reaction gas supply passage across the center of the reaction chamber in the side wall portion.

The epitaxial growth apparatus of the present invention comprises a ceiling plate, a substrate mounting portion (susceptor) on which a substrate is horizontally mounted and which is rotatable about a vertical axis passing through the center of the substrate, and side walls. a reaction chamber having an upper surface, a lower surface, and a side surface, respectively; a reaction gas supply passage formed in the side wall for supplying a reaction gas to the reaction chamber; and a gas discharge path for discharging the reaction gas that has passed through the reaction chamber to the outside, the gas discharge path being formed at a position facing the reaction gas supply path on both sides, wherein a film is formed by epitaxial growth on the upper surface of the substrate in the reaction chamber. The apparatus includes a support portion that supports the ceiling plate from above and outside the peripheral edge portion of the ceiling plate, and a horizontal flow direction of the reaction gas in the reaction chamber in the reaction gas supply path. so that the directional component matches the horizontal component in the direction from the center of the reaction chamber side opening of the reaction gas supply channel toward the center of the reaction chamber,
A rectifying means for rectifying the reaction gas is further provided.

Here, it is preferable that the support part supports the ceiling plate so that the distance between the ceiling plate and the upper surface of the substrate is equal to or less than a predetermined value.

Also, the reaction gas supply path may be formed in a stepped fashion upward from the reaction gas inlet toward the outlet connected to the reaction chamber. In this case, a plurality of raw material gases that are raw materials for the reactive gas are mixed in the stepped reaction gas supply path.

The gas discharge path may be connected to a gas discharge portion arranged outside the side wall portion, and the gas discharge portion may be formed so that the opening becomes narrower from the inside to the outside of the side wall portion.

A susceptor ring portion may be provided on the outer periphery of the substrate mounting portion to preheat the reaction gas.
The susceptor ring portion includes an outer peripheral ring portion mounted on a flange portion provided on the side wall portion,
Consists of two members, an inner peripheral ring portion placed in a recess provided on the upper surface of the outer peripheral ring portion,
The inner peripheral ring portion may have an inner diameter that narrows the gap between the peripheral edge portion of the substrate mounting portion and the inner peripheral edge portion of the outer ring portion. In this case, the inner peripheral ring prevents the reaction gas from flowing from the peripheral edge of the substrate platform to the lower surface side of the substrate platform.

The substrate platform may have a large number of through holes.

A first heating means for heating the inside of the reaction chamber to a predetermined growth temperature is provided in the upper part of the reaction chamber.
A first reflector is provided above the heating means, a second heating means is provided below the reaction chamber for heating the inside of the reaction chamber to a predetermined growth temperature, and a second reflector is provided below the second heating means. may be provided. In this case, the first reflector includes a first inclined portion that reflects the heat ray from the first heating means toward the center of the reaction chamber, and a first inclined portion that reflects the heat ray from the first heating means vertically downward. A flat portion is provided so that the area ratio of the first inclined portion and the first flat portion is a predetermined ratio, and the distribution of the first inclined portion and the first flat portion is not biased. , the first inclined portion and the first flat portion are preferably arranged. The second reflector also has a second inclined portion for reflecting the heat ray from the second heating means toward the center of the reaction chamber and a second flat portion for reflecting the heat ray from the second heating means vertically upward. so that the area ratio of the second inclined portion and the second flat portion is a predetermined ratio and the distribution of the second inclined portion and the second flat portion is not biased, the second It is preferable to arrange two inclined portions and a second flat portion.

According to the film forming method by epitaxial growth and the epitaxial growth apparatus of the present invention, the support part supports the ceiling plate from the upper outside of the ceiling plate. It is possible to reliably support the ceiling panel even in a high state. Therefore, the thickness of the boundary layer can be reduced, which contributes to increasing the growth rate. On the other hand, before the reaction gas is introduced into the reaction chamber, in the reaction gas supply channel provided on the side wall, the horizontal component of the flow direction of the reaction gas in the reaction chamber is shifted to the reaction chamber side of the reaction gas supply channel. Since the reaction gas is rectified so as to match the horizontal component in the direction from the center of the opening of the reaction chamber toward the center of the reaction chamber, as the boundary layer narrows, the substrate surface in the reaction chamber becomes It is possible to suppress an increase in the flow of reactant gas escaping toward the periphery, which contributes to stabilization of the reactant gas flow. As a result, stable high-speed growth can be achieved while ensuring film formation quality from the viewpoint of film thickness distribution, resistivity distribution, and the like.

1 is a cross-sectional view showing the entire epitaxial growth apparatus according to an embodiment of the present invention; 1 is an exploded perspective view showing the configuration of a reaction chamber in an embodiment of the present invention; FIG. 1 is an exploded perspective view showing the configuration of the outside of a reaction chamber in an embodiment of the present invention; FIG. FIG. 2 is a perspective cross-sectional view showing the structure of the ceiling part according to the embodiment of the present invention; Schematic diagram showing the configuration inside the side wall portion in the embodiment of the present invention. FIG. 2 is a cross-sectional view showing a reactive gas supply passage according to an embodiment of the present invention; Schematic diagram for explaining a reaction gas supply path in an embodiment of the present invention. 1 is a perspective view showing an example of a rectifying plate according to an embodiment of the present invention; FIG. 1 is a partial cross-sectional view showing an example of a susceptor ring according to an embodiment of the present invention; FIG. FIG. 4 is a partial cross-sectional view showing another example of the susceptor ring according to the embodiment of the present invention; 1 is a plan view showing an example of a susceptor according to an embodiment of the present invention; FIG. FIG. 4 is a plan view showing another example of the susceptor according to the embodiment of the present invention; Schematic diagram showing the configuration of a susceptor supporting portion according to an embodiment of the present invention. 1 is a perspective view showing an example of a susceptor shaft according to an embodiment of the present invention; FIG. FIG. 2 is a perspective view showing an example of a substrate/lift section according to an embodiment of the present invention; 1 is a perspective cross-sectional view showing an example of a gas discharge tube according to an embodiment of the present invention; FIG. The perspective view which shows an example of the upper reflector in embodiment of this invention. 1 is a perspective view showing an example of a lower reflector according to an embodiment of the invention; FIG. Graph showing results of Examples and Comparative Examples A perspective cross-sectional view showing the structure of a ceiling part in a conventional epitaxial growth apparatus. An exploded perspective view showing the structure of the outside of the reaction chamber in a conventional epitaxial growth apparatus. A perspective view showing an example of an upper reflector in a conventional epitaxial growth apparatus A perspective view showing an example of a lower reflector in a conventional epitaxial growth apparatus

An epitaxial growth apparatus and a film formation method using epitaxial growth performed by this apparatus, which are embodiments of the present invention, will be described below.

(Overview of configuration of epitaxial growth system)
First, the configuration of an epitaxial growth apparatus 1 according to an embodiment of the present invention will be outlined. FIG. 1 is a cross-sectional view showing the entire epitaxial growth apparatus 1. As shown in FIG. 2 is an exploded perspective view showing the configuration of the reaction chamber 2 of the epitaxial growth apparatus 1, and FIG. 3 is an exploded perspective view showing the configuration outside the reaction chamber 2 of the epitaxial growth apparatus 1. As shown in FIG.

The epitaxial growth apparatus 1 is a film formation apparatus for epitaxially growing a film of silicon or the like on a substrate W, for example.

An epitaxial growth apparatus 1 has a reaction chamber 2 . The reaction chamber 2 is composed of a susceptor 3 on which the substrate W is placed, a side wall portion 4 and a ceiling portion 5 .

The susceptor 3 is a circular plate-like member when viewed from above, and is configured to be slightly larger than the substrate W. As shown in FIG. The susceptor 3 is provided with a substrate concave portion 3a on which the substrate W is placed. The susceptor 3 is supported by a susceptor support 6 having a plurality of arms.

The susceptor support part 6 moves the susceptor 3 up and down while supporting the susceptor 3 . Susceptor 3
The elevation range of the surface on which the substrate W is placed is from the film formation position P1 where the film is formed on the substrate W of the susceptor 3 to the substrate transfer position P2 where the substrate W is transferred into and out of the epitaxial growth apparatus 1. Between. The susceptor supporter 6 is configured so that the susceptor 3 and the substrate W can be rotated by rotating about the axis of the susceptor supporter 6 at the film formation position P1.

A ring-shaped susceptor ring 7 is arranged around the susceptor 3 at the film forming position P1. The susceptor ring 7 is composed of a first ring 11 and a second ring 12 placed on the first ring 11, which will be described later in detail. The susceptor ring 7 is supported by a flange portion 13 provided on the side wall portion 4 of the reaction chamber 2 .

The ceiling portion 5 is composed of a ceiling plate 21 and a support portion 22 that supports the ceiling plate 21 . ceiling plate 21
is permeable so that the heat from the heating means 23 (for example, a halogen lamp) and the upper reflector 26 provided on the outer side of the ceiling plate 21 can pass through to heat the inside of the reaction chamber 2. is configured to That is, the epitaxial growth apparatus 1 in this embodiment is a cold wall type epitaxial growth apparatus. In this embodiment, quartz is used as the ceiling plate 21 .

A support portion 22 that supports the ceiling plate 21 is annular. Through hole 2 inside the inner edge of support part 22
A ceiling plate 21 is fixed to the end of the substrate W side of 4 . Welding can be used as a fixing method.

The sidewall portion 4 is composed of an annular upper sidewall portion 31 and an annular lower sidewall portion 32 . The flange portion 13 described above is provided on the inner peripheral side of the lower side wall portion 32 . A substrate transfer port 30 is provided below the flange portion 13 . The upper side wall portion 31 has a sloped portion on its upper surface corresponding to the sloped portion on the outer side of the projecting portion 25 of the support portion 22 . A support portion 22 is arranged on the slope of the upper side wall portion 31 .

A portion of the outer peripheral portion of the upper surface of the lower side wall portion 32 is notched, and the area where the notch is not provided is configured as a mounting surface 33 on which the upper side wall portion 31 is mounted. Lower side wall portion 32
A first recessed portion 34 is formed in the lower side wall portion 32 by the notch of . That is, the first concave portion 34 is a concave portion formed in a portion of the upper surface of the lower side wall portion 32 where the mounting surface 33 is not formed. In the upper side wall portion 31, a gap 35 corresponding to the shape of the first concave portion 34 and between the first concave portion 34 and the first concave portion 34 is provided at a position corresponding to the first concave portion 34 when placed on the lower side wall portion 32. The first convex portion 36 is provided so that a is formed. Then, the first convex portion 36 and the first concave portion 34
and functions as a reaction gas supply passage 41 (supply passage). The reactive gas supply passage 41 will be described later in detail.

Further, in a region of the lower side wall portion 32 facing the first concave portion 34 , the upper surface of the lower side wall portion 32 is partially cut out to form a second concave portion 37 . The upper side wall portion 31 has a gap 38 corresponding to the shape of the second concave portion 37 and between the second concave portion 37 and the second concave portion 37 at a position corresponding to the second concave portion 37 when placed on the lower side wall portion 32 . is formed, the second convex portion 39
is formed. The second concave portion 37 and the second convex portion 39 of the upper side wall portion 31 form the gas discharge path 4 .
2 is formed.

As described above, the reaction gas supply path 41 and the gas discharge path 42 face each other in the reaction chamber 2, and the reaction gas flows horizontally over the substrate W in the reaction chamber 2. As shown in FIG.

A purge hole 44 through which the purge gas is discharged is formed in the wall surface 43 forming the second concave portion 37 of the lower side wall portion 32 . The purge hole 44 is provided below the flange portion 13 . Since the purge hole 44 is provided in the wall surface 43 forming the second recess 37 , the purge hole 44 faces the gas discharge passage 42 . Therefore, both the reaction gas and the purge gas are discharged through the gas discharge path 42 .

An annular mounting table 45 is provided on the lower surface side of the lower side wall portion 32 of the side wall portion 4 , and the side wall portion 4 is mounted on the mounting table 45 .

An annular holding portion 51 is provided on the outer peripheral side of the ceiling portion 5, the side wall portion 4, and the mounting table 45.
The annular holding portion 51 clamps and supports the ceiling portion 5 , the side wall portion 4 and the mounting table 45 . The holding portion 51 is provided with a supply-side communication passage 52 communicating with the reaction gas supply passage 41 and a discharge-side communication passage 53 communicating with the gas discharge passage 42 . A gas introduction tube 55 is inserted into the supply side communication passage 52 . Also, the gas discharge tube 5 is connected to the discharge side communication passage 53 .
8 is interpolated.

A reaction gas introduction portion 54 is provided outside the holding portion 51 , and the reaction gas introduction portion 54 and the supply side communication passage 52 communicate with each other. In this embodiment, the first raw material gas and the second raw material gas are introduced from the reactive gas introduction section 54 . Note that the second source gas also functions as a carrier gas. As the reaction gas, it is also possible to use a mixture of three or more kinds of gases. A rectifying plate 56 is provided at a connecting portion between the supply-side communication passage 52 and the reaction gas introduction portion 54 so as to be perpendicular to the gas flow path. The current plate 56 has a plurality of holes 56a arranged in a line along the circumferential direction, and the reactant gas passes through the holes 56a to mix the first source gas and the second source gas. is rectified as the A gas discharge portion 57 is also provided outside the holding portion 51 . The gas discharge part 57 is provided at a position facing the reaction gas introduction part 54 across the center of the reaction chamber 2 . The gas discharge portion 57 and the discharge-side communication passage 53 communicate with each other. That is, the reactant gas introduction portion 54 is connected to the reactant gas supply passage 41 via the supply-side communication passage 52 . A gas discharge portion 57 is connected to the gas discharge passage 42 via a discharge side communication passage 53 . The gas discharge path 42 is provided so as to face the reaction gas supply path 41 across the center of the reaction chamber 2 .

In addition, an apparatus bottom portion 61 is provided at the inner peripheral side lower portion of the mounting table 45 . Another heating means 62 and a lower reflector 65 are provided on the outside of the device bottom 61 so that the substrate W can also be heated from below.

A purge gas introducing portion (not shown) into which the shaft portion 63 of the susceptor support portion 6 is inserted and a purge gas is introduced is provided in the center of the device bottom portion 61 . The purge gas is supplied to the device bottom 61 and the lower side wall 32 from purge gas introducing means (not shown) provided in the purge gas introducing portion.
and the mounting table 45 are introduced into the lower part 64 of the reaction chamber. Also, the purge hole 44 communicates with the reaction chamber lower portion 64 .

(Overview of film formation method using epitaxial growth)
Next, a film formation method using the epitaxial growth apparatus of this embodiment will be described.

First, the susceptor 3 is moved to the substrate transfer position P2, the substrate W is loaded from the substrate transfer port 30, and the susceptor 3 is moved to the film formation position P1. The substrate W has a diameter of, for example, 200 mm.
A silicon substrate is used. Next, the heating means 23 and 62 are heated to a standby temperature (for example, 800°C).
to the growth temperature (eg 1100° C.). A purge gas (for example, hydrogen) is introduced into the reaction chamber lower part 64 from the purge gas introduction port. Also, a reaction gas (for example, trichlorosilane as the first source gas and hydrogen as the second source gas) is supplied from the reaction gas introduction part 54 to the reaction gas supply path 41 .
is introduced into the reaction chamber 2 via the The reactive gas forms a boundary layer on the surface of the substrate W, in which reaction occurs. Thereby, a silicon film is formed on the substrate W. Next, as shown in FIG. The reaction gas is discharged from a gas discharge passage 42 facing the reaction chamber 2 . Also, the purge gas is discharged to the gas discharge passage 42 through the purge hole 44 . After the epitaxial growth is completed in this way,
After the temperature is lowered to the standby temperature, the substrate W is unloaded and moved to another chamber of the semiconductor manufacturing apparatus.

(Details of epitaxial growth equipment and method)
Next, the details of the constituent members of the epitaxial growth apparatus 1 of this embodiment will be described, and the details of the film forming method of this embodiment will also be described.

FIG. 4 is a perspective cross-sectional view showing the configuration of the ceiling section 5 in this embodiment. As shown in the figure, the inner edge of the support portion 22 that supports the ceiling plate 21 gradually decreases in diameter toward the substrate side. A ceiling plate 21 is fixed to the substrate W side end of the inner edge. Also, the support portion 2
2 is viewed from the back side (lower side), the inner peripheral portion protrudes to form a protruding portion 25 . The projecting portion 25 is also formed so that the diameter gradually decreases in the projecting direction. Thus, the support portion 22 is composed of two slope portions. That is, the support portion 22 supports the ceiling plate 21 at the peripheral edge portion of the ceiling plate 21 from above and outside the peripheral edge portion. On the other hand, FIG. 20 is a perspective sectional view showing an example of a ceiling portion 5' of a conventional epitaxial growth apparatus. As shown in the figure, in the ceiling part 5' of the conventional apparatus, the support part 22'
' supports the ceiling plate 21' from the same plane as the support 22', and the support portion 22' has a substantially right-angled corner portion 25'.

As described above, in this embodiment, the supporting portion 22 has a shape in which stress is less likely to concentrate than in the conventional one. can be done.

Specifically, infrared rays from the heating means 23 generally pass through the ceiling plate 21 (21'), but the ceiling plate 21 (21') itself absorbs radiant heat from the susceptor 3 or the substrate W. FIG. This absorbed heat is transferred from the ceiling plate 21 (21') to the support section 22 through the joint with the support section 22 (22').
(22'). Here, when the distance H between the substrate W and the ceiling plate 21 (21') is shortened, the absorption amount of this radiant heat increases, and the heat input to the support portion 22 (22') increases.
Therefore, if the support portion 22' has a substantially right-angled corner portion 25' as in the conventional ceiling portion 5', stress is concentrated on the corner portion 25', which may cause cracking or the like.

On the other hand, in the present embodiment, by providing the support portion 22 with the protruding portion 25 and supporting the ceiling plate 21 from above and outside the peripheral portion of the peripheral portion of the ceiling plate 21, the corners ( 25'), the ceiling plate 21 can be supported on the board side.

In addition, in this embodiment, the distance H between the ceiling plate 21 and the substrate W is shortened in order to narrow the boundary layer as described above. Since it may be difficult to make the film thickness distribution uniform, it is preferable to prevent this. For this reason, in this embodiment, a guide portion is provided in the reaction gas supply path 41 in order to make the gas flow uniform, as described below.

The guide portion provided in the reaction gas supply path 41 will be described in detail with reference to FIGS. 5 to 7. FIG. As described above, the reaction gas supply passage 41 is formed by the first concave portion 34 of the lower side wall portion 32 and the first convex portion 36 of the upper side wall portion 31 , and the gas introduction tube 55 in the supply side communication passage 52 passes through the reaction gas supply passage 41 . , and communicates with the reaction gas introduction portion 54 . In addition, the reactive gas supply path 41 is a first supply path 71 extending in a direction (horizontal direction) that coincides with the introduction direction of the gas from the reactive gas introduction portion 54.
and a second supply path 72 that communicates with the first supply path 71 and extends in a direction (vertical direction) perpendicular to the gas introduction direction, and communicates with the second supply path 72 and communicates with the gas introduction direction. and a third supply path 73 extending in a direction (horizontal direction) corresponding to . The third supply path 73 communicates with the reaction chamber 2 . That is, the reaction gas supply passage 41 is connected to the supply side communication passage 5 which is the inlet of the reaction gas.
From side 2, it is formed in an upward staircase shape toward an outlet connected to reaction chamber 2, which is an outlet for the reaction gas.

Here, since the second supply passage 72 extends in the vertical direction as described above, the gas introduced from the reaction gas introduction portion reaches the wall surface 74 of the second supply passage 72 facing the reaction gas introduction portion 54 . come into contact with As a result, the reactant gas is diffused and the mixability of the reactant gas is enhanced. That is, the second supply path 72 functions as a reaction gas mixing chamber. In this case, in order to prevent the reaction gas from stagnating in the second supply path 72, in this embodiment, the wall surface 74 of the second supply path 72 is formed with a groove 75 extending in the vertical direction. functions as a guide. In this way, the groove portion 75
is provided, the gas diffused by coming into contact with the wall surface 74 of the second supply path 72 also easily flows into the third supply path 73, and is rectified along the groove 75, so that the reaction The straightness of the gas is improved, and the spread of the reaction gas when it flows into the reaction chamber 2 can be suppressed.

The groove portion 75 will be described in detail. A plurality of grooves 75 are continuously formed as recesses on the entire surface of the wall surface 74 of the second supply path 72 . As shown in FIG. 7( 2 ), the groove portion 75 which is a concave portion is curved in the width direction of the groove portion 75 . In the present embodiment, the groove portion 75 has an arc shape when viewed from above. Since the groove portion 75 is curved in the width direction, the reaction gas
4, it is difficult to diffuse (easy to concentrate), and even if the reaction gas flows into the reaction chamber 2, it is more difficult to spread to the outside of the substrate W. As shown in FIG. If the groove 75 is too deep, diffusion can be suppressed, but it becomes difficult to mix the first source gas and the second source gas in the reaction gas. In one embodiment of the present invention, the depth of groove 75 is preferably between 1 mm and 5 mm. Furthermore, it is more preferable to set it to 3 mm.

Further, the grooves 75 are provided so as to face the center C of the lower side wall portion 32 in the in-plane direction. That is, the groove portion 75 is provided along the circumferential direction of the lower side wall portion 32 . With this arrangement, the horizontal component of the direction of flow of the reaction gas introduced into the reaction chamber 2 while being guided by the grooves 75 is directed from the center of the opening of the reaction gas supply passage 41 on the reaction chamber 2 side. The rectification is enhanced so as to coincide with the horizontal component directed toward the center of the reaction chamber 2 , and the reaction gas is suppressed from being dispersed within the reaction chamber 2 .

Furthermore, each groove 75 is provided at a position where the center of each groove 75 in the width direction and the center of the hole 56 a of the rectifying plate 56 provided in the reaction gas introduction section 54 substantially coincide (correspond). Namely
In this embodiment, the number of grooves 75 and the number of holes 56a on the wall surface 74 are the same. As a result, the reactant gas rectified by the rectifying plate 56 flows into each groove 75 as it is, so that the rectifying action is further enhanced and the straightness of the reactant gas can be improved.

Although the groove portion 75 is provided on the entire surface of the wall surface 74 of the second supply path 72 in this embodiment, it may be provided at least on the end portion of the wall surface 74 of the second supply path 72 . The term "end portion" refers to a portion corresponding to the end portion of the plurality of regions in which the holes of the rectifying plate 56 are divided. For example, in the case shown in FIG. 7, the straightening plate 56 is divided into three regions 81, and among these regions, grooves 75 correspond to the holes in regions 82 and 83 at the extreme ends.
should be provided. Since the reaction gas tends to escape to the outside of the substrate W as described above, it is preferable to provide the groove 75 at the end portion of the reaction gas supply path 41 in order to improve the straightness of the reaction gas. In this case, such an effect can be easily obtained by forming the groove portion 75 functioning as a guide portion as a concave portion. For example, if the rectifying member is separately provided in the second supply path 72, problems such as the miscibility of the reaction gas and the manufacturing cost will occur. is resolved.

FIG. 8 is a perspective view showing an example of the current plate 56. As shown in FIG. As shown in the figure, the straightening plate 56 may be prepared according to the pattern of the grooves 75 . It is preferable that the aperture ratio of the rectifying plate 56 is determined to be an optimum value not only from the viewpoint of the growth rate, but also from the perspective of the scrubber and incidental equipment such as the shape and length of the external piping.

In this embodiment, since the distance between the ceiling plate 21 and the substrate W is narrowed in order to narrow the boundary layer as described above, the reaction gas tends to flow into the lower part of the reaction chamber 2, and the substrate W.
As a result, it is conceivable that the film thickness distribution and film quality (for example, the distribution of resistivity and the occurrence of crystal defects) may deteriorate during the formation of a thick film. In this embodiment, the susceptor ring 7 is composed of two members to prevent this. This point will be explained.

As shown enlarged in FIG. 9, the first ring 11 constituting the susceptor ring 7 is provided apart from the outer periphery of the susceptor, and the inner periphery of the first ring has a lower upper surface. A step portion 91 is formed. The second ring 12 is placed on the stepped portion 91, and the second ring 12 is
The ring 12 is provided so as to face a spaced portion 92 formed between the first ring 11 and the susceptor 3 , that is, protrude into the spaced portion 92 . The second ring 12 is provided so that its upper surface is flush with the upper surface of the susceptor 3 . Thus, the upper surface of the second ring 12 is connected to the susceptor 3
, the reactant gas mixed in the reactant gas supply path 41 or the like and maintained in a rectified state can be smoothly supplied to the substrate W without lowering the speed as much as possible. . It should be noted that the upper surface of the susceptor 3 here means the recessed portion 3 for the substrate of the susceptor 3 .
a (see FIGS. 1, 2, 11 and 12) refers to the upper surface of the region where no formation is made. The second ring 12 of this embodiment is made of silicon carbide in view of its thermal conductivity.

By forming the second ring 12 and the first ring 11 from different members in this manner, the susceptor ring 7 can be formed with higher accuracy. That is, the distance between the susceptor ring 7 and the susceptor 3 can be made as close to the limit as possible. can be Thereby, in the present embodiment, the film thickness distribution and film quality distribution of the formed film are made uniform.

In addition, by using the first ring 11 and the second ring 12 as two members, the transfer of heat between the first ring 11 and the second ring 12 can be controlled by combining the first ring 11 and the second ring 12 into one member. can be suppressed more than when configured with

Furthermore, since the second ring 12 is configured to face the spaced portion 92 in this way,
Since it is possible to reduce the downward leakage of the reaction gas from between the susceptor ring 7 and the susceptor 3 during film formation, the flow of the reaction gas is less likely to be disturbed, and the downward leakage of the reaction gas can be reduced. can be reduced.

In this case, the second ring 12 is formed thinner than the first ring 11 . Thereby, heat loss due to radiation from the susceptor 3 can be suppressed. In addition, since the second ring 12 is thin, the amount of heat required to maintain the second ring 12 at a predetermined high temperature (preheating) can be reduced. As another embodiment, when the first ring 11 is made of a material with low thermal conductivity, the first ring 11 functions as a heat insulating material, and the above effects can be further enhanced.

Although the second ring 12 is configured to face the separation portion 92 in the present embodiment, the present invention is not limited to this. As long as the second ring 12 is configured to be placed at least on the stepped portion 91 of the first ring 11 , the susceptor ring 7 can be configured with high accuracy. can be brought close to the limit, thereby making it possible to reduce the reaction gas flowing into the back surface side of the substrate W and to make the temperature distribution of the substrate uniform.

Further, in this embodiment, the distance between the ceiling plate 21 and the substrate W is narrowed in order to narrow the boundary layer, so the ceiling surface of the ceiling plate 21 is also easily coated with the reactive gas. If the ceiling surface is coated, the ceiling surface becomes cloudy, and a cold wall type epitaxial growth apparatus that heats from the heating means 23 through the ceiling plate 21 may not be able to sufficiently form a film. On the other hand, in this embodiment, the groove portion 7 is formed on the wall surface of the reaction gas supply passage 41 as described above.
5 and the susceptor ring 7 is made up of two members, the reaction gas can flow into the reaction chamber 2.
As a result, adhesion of the coating material can be suppressed. Thereby, it is possible to perform sufficient film formation continuously.

FIG. 10 shows a modification of the susceptor ring 7. As shown in FIG. This modification differs from the embodiment shown in FIG. 9 in that the second ring 12A is provided so as to cover the spacing portion 92A. Also in this modified example, the first ring 11A is mounted on the flange portion 13A of the side wall portion 32A. The second ring 12A is placed on the stepped portion 91A of the first ring 11A,
Moreover, the inner peripheral side faces the outer periphery of the susceptor 3A.

In this modification, the second ring 12A is provided so as to cover the spaced portion 92A,
Reaction gas that has flowed into the reaction chamber 2A can be further suppressed from entering the reaction chamber lower portion 64A. However, the second ring 12A is heated from the heating means 23 (not shown in FIG. 10) to the susceptor 3A.
It is preferable that the amount of overlap between the second ring 12A and the susceptor 3A is small in order to prevent blocking of the heating of the second ring 12A.

In this modification, the thickness of the second ring 12A is preferably 0.5 mm to 2 mm, for example. Furthermore, it is more preferable to set it to about 0.8 mm. By setting such a thickness,
Heat loss due to radiation from the susceptor 3A to the second ring 12A can be suppressed as much as possible.

11 and 12 are plan views showing an example of the susceptor 3 in the embodiment of the invention. As shown in the figure, the susceptors 3A and 3B are provided with lift pin through holes 110A and 110B through which the lift pins 123 (see FIG. 13) pass. Also, as shown in FIG. 12, it may have a large number of through holes 111B. The through hole 111B allows the gas sandwiched between the substrates to be released at the moment the substrate is placed on the susceptor, thereby solving the problem of the substrate W slipping in the horizontal direction. Further, the use of such a susceptor 3B is superior to the use of the susceptor 3A in terms of uniformity of film thickness distribution and uniformity of resistivity distribution of the substrate W. FIG. This is more conspicuous as the diameter of the through-holes 111B is smaller and the number of through-holes 111B is larger. Further, the aperture ratio is preferably more than 4%, and the through hole 1 is formed not only in the substrate recess 3Ba of the susceptor but also around it.
11B is more preferred.

13 to 16 show one embodiment of the susceptor support 6. FIG. Figure 13
, the susceptor support portion 6 includes a susceptor shaft 121 and a substrate lift portion 122.
and lift pins 123 . Susceptor 3 is 3 of susceptor shaft 121
It is supported by the arms of the book. Lift pins 1 are provided on the three arms of the substrate lift section 122
A pedestal 124 is provided which has a recess in which the lower end of 23 is placed. The shaft portion of the substrate lift portion 122 is cylindrical, and the shaft portion of the susceptor shaft 121 can be inserted into the shaft portion of the substrate lift portion 122 .

In this embodiment, in the susceptor support portion 6, the thickness of each arm portion is thinner than usual. As a result, the influence of the susceptor supporting portion 6 when the heating means 62 heats the substrate W on the susceptor 3 can be reduced, so that the temperature distribution of the susceptor 3 can be made uniform. The details of the configuration of the susceptor support portion 6 of the present embodiment and the lifting operation are the same as those of the susceptor device disclosed in International Publication WO2013/005481 filed by the present applicant. However, although the susceptor device described in the publication has one susceptor shaft (mounting portion shaft), the susceptor shaft (mounting portion shaft) of the susceptor support portion 6 of the present embodiment is
There are three arms 121 .

FIG. 16 is a perspective cross-sectional view showing an example of the gas discharge tube 58 in this embodiment. As shown in the figure, the gas discharge tube 58 is formed such that the opening is constricted toward the center and becomes narrower from the reaction chamber 2 side toward the gas discharge portion 57 . As a result, the exhaust gas is rectified to the center, and the exhaust efficiency is improved.

Also, FIG. 21 is an exploded perspective view showing the structure of the outside of the reaction chamber 2 in the conventional epitaxial growth apparatus. As shown in the figure, when gas introduction tubes 55 and 55' and gas discharge tubes 58 and 58' are compared, in the present embodiment, the partition portion in the center of each is removed. This smoothes the flow of the gas that affects the film thickness distribution.

If the gas exhaust path 42 and the purge hole 44 have too large opening ratios, the reaction gas will enter the lower part 64 of the reaction chamber. Therefore, the opening is formed so as to have an optimum value.

FIG. 17 is a perspective view showing an example of the upper reflector 26 according to the embodiment of the invention.
As shown in the figure, the upper reflector 26 has an inclined portion 26a that reflects the heat ray from the heating means 23 toward the center of the reaction chamber 2, and a flat portion 26b that reflects the heat ray from the heating means 23 vertically downward. have. On the other hand, FIG. 22 is a perspective view showing an example of an upper reflector 26' in a conventional epitaxial growth apparatus. As shown, the conventional upper reflector 26' also has an inclined portion 26a' and a flat portion 26b', but the arrangement of the inclined portion 26a differs from that of the upper reflector 26 of the embodiment of the present invention. there is Specifically, the top reflector 26 of the embodiment of the present invention has an arrangement in which one ramp is added in the center of the flat portion 26b' of the conventional top reflector 26'. In this manner, the inclined portions 26a and the flat portions 26b are arranged so that the area ratio of the inclined portions 26a and the flat portions 26b is a predetermined ratio and the distribution of the inclined portions 26a and the flat portions 26b is not biased. By doing so, the temperature distribution of the substrate W is made uniform.

FIG. 18 is a perspective view showing an example of the lower reflector 65 according to the embodiment of the invention.
FIG. 23 is a perspective view showing an example of a lower reflector 65' in a conventional epitaxial growth apparatus. Similarly to the upper reflector 26, the lower reflector 65 has an inclined portion 65a for reflecting the heat ray from the heating means 62 toward the center of the reaction chamber 2 and a flat portion 65b for reflecting the heat ray from the heating means 62 vertically upward. The arrangement is such that one inclined portion is added in the center of the flat portion 65b' of the conventional lower reflector 65'. In this way, the inclined portion 65a
and the flat portion 65b is a predetermined ratio, and the inclined portion 65a and the flat portion 65b
By arranging the inclined portion 65a and the flat portion 65b so that the distribution of the substrate W
uniformity of temperature distribution is achieved.

According to the epitaxial growth apparatus of the present embodiment, the support portion 22 supports the ceiling plate 21 so that the distance H between the ceiling surface of the central portion of the ceiling plate 21 on the side of the reaction chamber and the substrate W is less than 10 mm. can be done. As a result, the epitaxial growth apparatus 1 of the present embodiment can prevent the boundary layer formed by the reaction gas flowing between the ceiling plate 21 and the susceptor 3 from spreading toward the ceiling, resulting in a narrower boundary layer. As a result, the gas velocity in this boundary layer is increased, and as a result, the gas density is improved, and the reaction efficiency on the surface of the substrate W can be enhanced. Thereby, the epitaxial growth apparatus 1 can improve the growth rate.

In one embodiment of the present invention, the distance H between the ceiling plate 21 and the substrate W is less than 10 mm,
Preferably, the distance H between the ceiling plate 21 and the substrate W is less than 10 mm, and the distance between the surface of the film formed on the substrate W and the ceiling plate 21 is 1 mm or more. With this range, the gas flow of the reaction gas can be performed smoothly while forming the boundary layer.

That is, in the reaction chamber 2 according to the present embodiment, the distance between the substrate W and the ceiling plate 21 is made shorter than in the conventional art (approximately 20 mm in the conventional art), thereby narrowing the boundary layer and increasing the reaction efficiency on the substrate surface.
As a result, it increases the growth rate.

(Example)
Hereinafter, the details of the invention will be described with reference to examples.

Epitaxial growth was performed using the epitaxial growth apparatus 1A (the distance H between the surface of the substrate W and the ceiling plate 21 was 9.27 mm) using the susceptor ring shown in FIG. 10 under the following growth conditions.
First source gas (trichlorosilane) flow rate 8.5 SLM
Purge gas (hydrogen) flow rate 15.0 SLM
Growth time 600.0 seconds Growth temperature 1100.0°C
Rotation speed 20.0 RPM

Epitaxial growth was performed under the same conditions as in Example 1, except that the amount of the first raw material gas was changed to 13.5 SLM.

Epitaxial growth was performed under the same conditions as in Example 1, except that the amount of the first raw material gas was changed to 17.0 SLM.
(Comparative example 1)

A conventional epitaxial growth apparatus (the distance H between the surface of the substrate W and the ceiling plate 21 is 20 mm, there is no groove 75, and the susceptor ring consists of one member) was used, except that the rotational speed was set to 35.0 RPM. Epitaxial growth was performed under the same growth conditions.
(Comparative example 2)

A conventional epitaxial growth apparatus (the distance H between the surface of the substrate W and the ceiling plate 21 is 20 mm, there is no groove 75, and the susceptor ring consists of one member) was used, except that the rotational speed was set to 35.0 RPM. Epitaxial growth was performed under the same growth conditions.
(Comparative Example 3)

A conventional epitaxial growth apparatus (the distance H between the surface of the substrate W and the ceiling plate 21 is 20 mm, there is no groove 75, and the susceptor ring consists of one member) was used, except that the rotational speed was set to 35.0 RPM. Epitaxial growth was performed under the same growth conditions.
The film growth rate of each example and comparative example was detected. FIG. 19 shows the relationship between the detected growth rate and the first source gas.

As shown in FIG. 19, according to the epitaxial growth apparatus 1A according to the embodiment of the present invention,
The growth rate was improved by 50% or more, and the rate of growth rate improvement increased as the amount of the first source gas increased. Therefore, the growth rate was improved by using the epitaxial growth apparatus of this embodiment.

Reference Signs List 1 epitaxial growth apparatus 2 reaction chamber 3 susceptor 4 side wall 5 ceiling 6 susceptor support 7 susceptor ring 11 first ring 12 second ring 13 flange 21 ceiling plate 22 support 23 heating means 24 through hole 25 projection 26 upper reflector 30 Substrate carry-out port 31 Upper side wall portion 32 Lower side wall portion 33 Placement surface 34 First concave portion 35 Gap 36 First convex portion 37 Second concave portion 38 Gap 39 Second convex portion 41 Reactive gas supply path 42 Gas discharge path 43 Wall surface 44 Purge hole 45 Mounting table 51 Clamping portion 52 Supply side communication passage 53 Discharge side communication passage 54 Reactive gas introduction portion 55 Gas introduction tubes 56, 56A, 56B Current plate 56a Hole 57 Gas discharge portion 58 Gas discharge tube 61 Device bottom 62 Heating Means 63 Shaft 64 Lower part of reaction chamber 65 Lower reflector 71 First supply channel 72 Second supply channel 73 Third supply channel 74 Wall surface 75 Groove parts 81, 82, 83 Area 91 Stepped part 92 Spacing parts 110A, 110B Lift pin through hole 111B Through hole 121 Susceptor shaft 122 Substrate lift part 123 Lift pin 124 Pedestal W Substrate

Claims (13)

A lower sidewall for use in a processing chamber configured to direct flow of reactant gases into the processing chamber to prevent dispersion of the reactant gases across the substrate surface, the annular body comprising: an annular body; teeth,
a vertical inner wall;
a central opening formed by vertical inner wall surfaces;
a vertical central axis disposed through the central opening and the center of the annular body;
an upper surface that connects at its inner edge to the upper edge of the vertical inner wall surface;
a vertical first outer wall surface connecting at its upper end to the outer edge of the upper surface,
The vertical first outer wall surface is provided with a plurality of vertical grooves, the plurality of vertical grooves forming a plurality of vertical gas paths, the plurality of vertical grooves receiving reactant gas at their bottom ends. rectifying and mixing the reactive gas before the reactive gas flows into the central opening of the processing chamber from the top surface ; and forming a plurality of vertical grooves continuously in the circumferential direction on the vertical first outer wall surface; the cross-sectional curved profile of each groove intersects the second curved profile of an adjacent groove;
each groove having a curved cross-sectional profile with a unique center;
The curved cross-sectional profile of each groove deepens toward a vertical central axis to control the flow direction of the reactant gas in a desired horizontal direction, thereby preventing dispersion of the reactant gas. When,
a first horizontal surface that connects at its inner end to the lower edge of the vertical first outer wall surface. a vertical second outer wall surface connecting at its upper end to the outer edge of the upper surface;
2. The lower sidewall portion of claim 1, further comprising a second horizontal surface connecting at its inner edge to the lower edge of the vertical second outer wall surface. 3. The lower sidewall section of claim 2, wherein the vertical second outer wall surface has a purge hole formed therethrough. 2. The lower sidewall of claim 1, wherein each groove has a depth of 1-5 mm to maintain mixing of reactant gases. A lower sidewall for use in a processing chamber configured to direct flow of reactant gases into the processing chamber to prevent dispersion of the reactant gases across the substrate surface, the annular body comprising: an annular body; teeth,
a vertical inner wall;
a central opening formed by vertical inner wall surfaces;
a vertical central axis disposed through the central opening and the center of the annular body;
an upper surface that connects at its inner edge to the upper edge of the vertical inner wall surface;
A first vertical outer wall surface that connects at its upper end to the outer end of the upper surface and is concentric with and shares a central axis with the vertical inner wall surface,
a plurality of vertical grooves provided in the vertical first outer wall surface, the plurality of vertical grooves forming a plurality of vertical gas passages, the plurality of vertical grooves receiving reactant gas at a bottom end thereof; rectifying and mixing the reactant gases before they enter the central opening of the processing chamber from the top surface;
each groove having a curved cross-sectional profile with a unique center;
The curved cross-sectional profile of each groove deepens toward a vertical central axis to prevent dispersion of the reactant gas by controlling the direction of flow of the reactant gas in a desired horizontal direction and to provide a vertical first outer groove. a plurality of vertical grooves are continuously formed in the wall surface in a circumferential direction, each groove having a cross-sectional curved profile intersecting a second curved profile of an adjacent groove; a first vertical outer wall surface;
a first horizontal surface connected at its inner end to the lower end of the first vertical outer wall surface, and on the side opposite the first outer wall surface with respect to the vertical central axis,
a vertical second outer wall surface connected at its upper end to the outer edge of the upper surface, the second vertical outer wall surface including a plurality of purge holes formed therethrough;
a second horizontal surface that connects at its inner end to the lower edge of the vertical second outer wall surface. 6. The lower sidewall portion of claim 5, wherein the first vertical outer wall surface has a plurality of circumferentially continuous vertical grooves formed therein. 6. The lower sidewall of claim 5, wherein the curved cross-sectional profile of each groove concentrates the gas when the gas contacts the plurality of vertical grooves. A ceiling used in a processing apparatus, wherein gas flowing between the ceiling and a substrate placed on a susceptor forms a narrow boundary layer,
an annular support having upper and lower surfaces;
a protrusion having one end connected to the inner periphery of the annular support, protruding from the inner surface of the annular support and radially inwardly protruding from the annular support, the protrusion being the annular support; a protrusion projecting away from the top surface as it projects radially inward from the
A ceiling plate having a peripheral edge portion, the peripheral edge portion being fixed to the second end of the protrusion so that the peripheral edge portion is supported from above and outside the peripheral edge portion, and the peripheral edge portion of the ceiling plate is supported on the lower surface. The ceiling plate is positioned below the top and bottom surfaces, and the ceiling plate is positioned close to the substrate to form a narrow boundary layer to prevent dispersion of reactant gases that enter the ceiling plate and substrate. A ceiling section having a ceiling plate that 2. The lower sidewall portion of claim 1, wherein each groove extends vertically along the vertical first outer wall surface. 2. The lower sidewall portion of claim 1, wherein the first vertical outer wall surface and the first horizontal surface define a first recess. 9. The ceiling of claim 8, wherein the ceiling panel is planar. 9. The ceiling of claim 8, wherein the ceiling plate comprises quartz material. the upper surface of the protrusion is coupled to the upper surface of the annular support and the upper surface of the ceiling plate;
9. The ceiling of claim 8, wherein the lower surface of the protrusion is joined to the lower surface of the annular support and to the lower surface of the ceiling panel.

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