JP2010040544A - Vapor deposition apparatus - Google Patents

Abstract

A vapor phase growth apparatus capable of uniforming the film thickness distribution of an epitaxial film is provided.
SOLUTION: A substantially rectangular parallelepiped chamber main body 10 and a gas introduction portion 20 provided in one end side wall portion 11 of the chamber main body and provided for each region divided in a direction transverse to the gas introduction direction; The gas discharge part 18 provided on the other end side wall part 14 of the chamber main body and the bottom wall part 16 of the chamber main body are rotatably provided, and a plurality of substrates W as processing objects are mounted on the circumference. And a rectifier 17 provided in the chamber body at a position where the gas introduced from the gas introduction part collides with the gas introduction part.
[Selection] Figure 2

Description

  The present invention relates to a vapor phase growth apparatus.

As a vapor phase growth apparatus for growing high-quality epitaxial films on the surface of semiconductor wafers such as silicon, cylinder furnaces (barrel path), vertical furnaces (pancake furnaces), horizontal furnaces, single wafers, based on their structural classification Various vapor phase growth apparatuses such as a furnace are known.

Among these, the horizontal type vapor phase growth apparatus is provided with a disk-shaped susceptor in a quartz-like horizontally long passage-shaped chamber, and a plurality of wafers are arranged on the circumference on the susceptor, and the wafer is transferred by a heater disposed on the outer surface of the chamber. While heating, a source gas and a carrier gas are allowed to flow parallel to the main surface of the wafer from one end of the chamber and exhausted from the other end of the chamber to grow an epitaxial film on the wafer surface (FIG. 1 of Patent Document 1). To FIG. 3).

JP 2006-173540 A

Since such an epitaxial growth process is performed under a supply rate-controlled condition in which the wafer is heated to a high temperature, the film thickness of the epitaxial film is easily affected by the flow velocity of the gas flowing on the wafer.

For this reason, the film thickness distribution is also controlled by dividing the gas inlet formed at one end of the chamber in the horizontal direction and controlling the flow rate for each region.

As a result of the search by the present inventors, it has been found that it is effective to make the flow velocity at the center of the susceptor faster than other regions in order to make the film thickness distribution in the wafer surface uniform. However, if the flow rate at the center of the chamber is made relatively fast in order to realize this, there is a problem in that back flow occurs in the side wall of the chamber and adhesion of by-products to the chamber wall surface is promoted.

The problem to be solved by the present invention is to provide a vapor phase growth apparatus capable of making the film thickness distribution of the epitaxial film uniform while suppressing adhesion of by-products to the chamber wall surface.

The vapor phase growth apparatus of the present invention is provided with a substantially rectangular parallelepiped chamber main body, and a gas introduction provided for each region divided in a lateral direction with respect to the gas introduction direction. And a gas discharge part provided on the other end side wall part of the chamber main body, and a bottom wall part of the chamber main body that is rotatably provided, and a single substrate as a processing object is formed concentrically or with a plurality of substrates. A vapor phase growth apparatus comprising a circumferentially mounted susceptor,
In the chamber main body, a rectifier is provided at a position where the gas introduced from the gas introduction portion to the chamber main body collides with the gas introduction portion.

  According to the present invention, since the gas introduced from the gas introduction part collides with the rectifier, the back flow of the gas in the chamber side wall part can be suppressed, so that the film thickness distribution of the epitaxial film can be made uniform. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view showing a vapor phase growth apparatus according to the present embodiment, and FIG. 2 is a cross-sectional view taken along line II-II in FIG.

  The vapor phase growth apparatus 1 of this example includes a quartz chamber body 10 having a substantially rectangular parallelepiped shape. “Substantially” is intended to include a substantially rectangular parallelepiped shape in addition to a cuboid in a strict sense.

  The chamber body 10 includes side wall portions 11 and 14 positioned at both ends in the longitudinal direction, and side wall portions 12 and 13, a ceiling wall portion 15, and a bottom wall portion 16 positioned between the side wall portions 11 and 14.

One side wall part 11 is provided with a gas introduction part 20, and the side wall part 14 facing this is provided with a gas discharge part 18. The gas introduction unit 20 is for diluting a Si source such as SiHCl ₃ with hydrogen gas and introducing a reaction gas obtained by mixing a small amount of the dopant into the chamber body 10. Show.

  The gas introduction part 20 of this example is provided on both sides of the central gas introduction part 22 and the central gas introduction part 22 that introduces the reaction gas mainly toward the central part of the chamber main body 10. , 13, and both side gas introduction portions 21, 23 for introducing the reaction gas, and these central gas introduction portion 22 and both side gas introduction portions 21, 23 are provided inside the side wall portion 11 with two partition plates 24, 25. It is comprised by providing. The partition plates 24 and 25 govern the action of rectifying the reaction gas ejected from the gas introduction unit 20 toward the chamber body 10.

  The reaction gas is supplied to the central gas introduction part 22 and the two side gas introduction parts 21 and 23 via the flow control valves 26, 27 and 28. The gas flow rate to each gas introduction part 21-23 is adjusted by controlling the opening degree of each flow control valve 26-28.

  The reaction gas introduced from the gas introduction unit 20 passes through the surface of the wafer W, grows an epitaxial film, and is then discharged from the gas discharge unit 18 to the outside of the vapor phase growth apparatus 1. The flow of this reaction gas is shown by a thick arrow in FIG.

  The gas discharge part 18 has a plurality of through holes 141 formed in the side wall part 14 and a discharge pipe 19, and the reaction gas flowing down in the chamber body 10 passes through the through holes 141 and passes through the gas discharge part. 18 is led out of the vapor phase growth apparatus 1 by the discharge pipe 19 from here.

  A susceptor 30 on which a silicon single crystal wafer W that is an object to be processed is mounted is provided on the bottom wall portion 16 at the substantially center of the chamber body 10. A plurality of susceptors 30 (in the illustrated example, eight wafers W are circumferentially mounted and rotated at a predetermined speed around the rotation shaft 32 (see the arrow in FIG. 1). For example, a carbon substrate coated with a SiC film is preferably used, for example, and the wafer W is loaded into the susceptor 30 or unloaded from the susceptor 30. The type is not limited, and any of a type in which a wafer is transferred by raising and lowering a transfer jig using a Bernoulli chuck and a type in which a wafer lower surface is supported by pins and transferred by raising and lowering the pins can be applied.

  A high frequency induction heating coil 31 is provided below the susceptor 30, and the susceptor 30 and the wafer W are heated by a radiant heat transfer effect.

  In the vapor phase growth apparatus 1 of this example, a plate-like member 17 is provided inside the chamber body 10 facing the gas introduction part 20 (21 to 23) for introducing the reaction gas into the chamber body 10. As shown in FIG. 1, the plate-like member 17 is provided across the left and right ends of the chamber body 10, and is provided so as to face not only the central gas introduction part 22 but also the positions where the reaction gases from both side gas introduction parts 21 and 23 are ejected. ing.

  In the example shown in FIG. 2, the introduction pipe (pipe from the gas supply source 29) of the gas introduction part 20 is provided at a position close to the ceiling wall part 15, so that the plate member 17 hangs down from the ceiling wall part 15. Provided.

  In this case, the angle θ formed by the plate member 17 and the direction in which the reaction gas is ejected from the introduction pipe of the gas introduction unit 20 (the direction indicated by the gas introduction direction in FIGS. 1 and 2) is set to 90 ° to 45 °. Is preferred. A case where θ = 45 ° is shown by a two-dot chain line in FIG. If θ is greater than 90 °, the introduced reaction gas is deflected toward the ceiling wall portion 15 and eddy currents are generated here, which is not preferable. Further, if θ is smaller than 45 °, the rectifying effect by the plate-like member 17 is reduced, which is not preferable.

  In addition, as shown in FIG. 2, it is preferable to select the set position of the plate member 17 so that 10 mm ≦ L1 ≦ 50 mm when the horizontal distance between the side wall portion 11 and the plate member 17 is L1. . If L1 is smaller than 10 mm, the horizontal distance between the plate-like member 17 and the side wall portion 11 becomes too small, and the introduced reaction gas is deflected rapidly, which is not preferable. On the other hand, if L1 is larger than 50 mm, the horizontal distance between the plate-like member 17 and the side wall portion 11 becomes too large, and the rectifying effect by the plate-like member 17 becomes small.

  Further, as shown in FIG. 2, the vertical distance between the ceiling wall 15 and the bottom wall 16 of the chamber body 10 is L2, the vertical distance between the ceiling wall 15 and the gas introduction part 20 is L3, and the plate-like member 17 The setting position and size of the plate-like member 17 are selected so that 0.1 ≦ L4 / L2 ≦ 0.5 and 0.2 ≦ L3 / L4 ≦ 1.0 when the vertical length is L4. It is preferable. If L4 / L2 is smaller than 0.1, the rectifying effect of the plate-like member 17 becomes small, which is not preferable. On the other hand, if L4 / L2 is greater than 0.5, the flow of the reaction gas is greatly inhibited by the plate-like member 17, which is not preferable. On the other hand, if L3 / L4 is smaller than 0.2, the flow of the reaction gas is largely alienated by the plate-like member 17, which is not preferable. On the other hand, if L3 / L4 is greater than 1.0, the introduced reaction gas hardly collides with the plate-like member 17 and the rectifying effect of the plate-like member 17 becomes small, which is not preferable.

  On the other hand, as shown in FIG. 3, the introduction pipe 29 of the gas introduction part 20 can be provided at a position close to the bottom wall part 16. In this case, the plate-like member 17 is erected on the low wall portion 16 of the chamber body 10. FIG. 3 is a cross-sectional view (corresponding to a cross-sectional view taken along line II-II in FIG. 1) showing a vapor phase growth apparatus 1 according to another embodiment. Parts common to the embodiment of FIG. 2 are denoted by the same reference numerals, and the description thereof is incorporated.

  In the example shown in FIG. 3, the angle θ formed by the direction in which the reaction gas is ejected from the introduction pipe of the gas introduction unit 20 (the direction indicated by the gas introduction direction in FIG. 3) and the plate member 17 is 90 ° to 45 °. It is preferable. A case where θ = 45 ° is shown by a two-dot chain line in FIG. If θ is greater than 90 °, the introduced reaction gas is deflected toward the bottom wall portion 16 and eddy currents are generated here, which is not preferable. Further, if θ is smaller than 45 °, the rectifying effect by the plate-like member 17 is reduced, which is not preferable.

  3, the vertical distance between the ceiling wall 15 and the bottom wall 16 of the chamber body 10 is L2, the vertical distance between the bottom wall 16 and the gas inlet 20 is L3, and the plate-like member 17 The setting position and size of the plate-like member 17 are selected so that 0.1 ≦ L4 / L2 ≦ 0.5 and 0.2 ≦ L3 / L4 ≦ 1.0 when the vertical length is L4. It is preferable. If L4 / L2 is smaller than 0.1, the rectifying effect of the plate-like member 17 becomes small, which is not preferable. On the other hand, if L4 / L2 is greater than 0.5, the flow of the reaction gas is greatly inhibited by the plate-like member 17, which is not preferable. On the other hand, if L3 / L4 is smaller than 0.2, the flow of the reaction gas is largely alienated by the plate-like member 17, which is not preferable. Further, if L3 / L4 is larger than 1.0, the introduced reaction gas hardly collides with the plate-like member 17 and the rectifying effect of the plate-like member 17 becomes small, which is not preferable.

  Next, the operation will be described.

  According to the present inventors, when the silicon epitaxial film is grown on the silicon single crystal wafer W by using the vapor phase growth apparatus 1 having the above-described structure, the film thickness distribution in the wafer surface is made uniform. It is effective to make the flow velocity at the center of the susceptor 30 faster than other regions.

  That is, if the flow rate of the central gas introduction part 22 shown in FIG. 1 is made faster than the flow rates of the gas introduction parts 21 and 23 on both sides, the film thickness distribution of the obtained silicon epitaxial film becomes uniform.

  However, when the flow rate at the center of the chamber body 10, that is, the flow rate of the central gas introduction part 22 is relatively increased, a backflow occurs at the side wall parts 12 and 13 of the chamber body 10 as shown in FIG. Adhesion of by-products to 12, 13 is promoted.

  On the other hand, in the vapor phase growth apparatus 1 of the present embodiment in which the plate-like member 17 is provided so as to face the gas introduction part 20, it is relatively early introduced from the central gas introduction part 22 as shown in FIG. The flow rate of the reaction gas collides with the plate-like member 17, changes the flow direction downward, and further deflects and flows toward the rotating susceptor 30 on which the wafer W is mounted. Similarly, the relatively slow flow rate of the reaction gas introduced from the gas inlets 21 and 23 collides with the plate-like member 17, changes its flow direction downward, and further rotates with the wafer W mounted thereon. It is deflected toward 30 and flows.

  Here, when the reaction gas having a high flow velocity from the central gas introduction portion 22 and the reaction gas having a low flow velocity from the both-side gas introduction portions 21 and 23 collide with the plate-like member 17 and are deflected, these interactions occur. This prevents backflow as shown in FIG.

  As a result, for the wafer W mounted on the susceptor 30 and rotating, the reaction gas having a high flow rate at the center and a low flow rate at both sides flows in parallel, and the film thickness distribution becomes uniform.

  In the above embodiment, a plurality of silicon wafers W are mounted on the susceptor 30, but the present invention can also be applied to a so-called single wafer vapor phase growth apparatus in which a single silicon wafer is mounted on the susceptor.

1 is a plan view showing a vapor phase growth apparatus according to an embodiment of the invention. It is sectional drawing which follows the II-II line of FIG. It is sectional drawing (equivalent to sectional drawing in alignment with the II-II line of FIG. 1) which shows the vapor phase growth apparatus which concerns on other embodiment of invention. It is a top view which shows the vapor phase growth apparatus which concerns on the comparative example of invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vapor growth apparatus 10 ... Chamber main body 11, 12, 13, 14 ... Side wall part 14 ... Ceiling wall part 16 ... Bottom wall part 17 ... Rectifier (plate-shaped member)
DESCRIPTION OF SYMBOLS 20 ... Gas introduction part 21, 23 ... Both-side gas introduction part 22 ... Central gas introduction part 24, 25 ... Partition plates 26, 27, 28 ... Flow control valve 29 ... Gas supply source 30 ... Susceptor 31 ... Heater W ... Wafer

Claims (7)

A substantially rectangular parallelepiped chamber body;
A gas introduction part provided on one side wall of the chamber body and provided for each region divided in a direction transverse to the gas introduction direction;
A gas discharge part provided on the other end side wall of the chamber body;
A susceptor that is rotatably provided on a bottom wall portion of the chamber body, and that has a single substrate as a processing object mounted concentrically or circumferentially.
A rectifier provided in the chamber body at a position where the gas introduced from the gas introduction part to the chamber body collides with the gas introduction part. Phase growth equipment. The vapor phase growth apparatus according to claim 1,
The gas introduction part is
A central gas introduction part for introducing gas mainly toward the central part of the chamber body;
A vapor phase growth apparatus, comprising: both side gas introduction parts which are provided on both sides of the central gas introduction part and introduce gas mainly along a side wall part of the chamber body. The vapor phase growth apparatus according to claim 2,
The vapor phase growth apparatus characterized in that the gas introduction amount from the central gas introduction portion is larger than the gas introduction amount from the both-side gas introduction portions. In the vapor phase growth apparatus according to any one of claims 1 to 3,
The vapor phase growth apparatus characterized in that the rectifier is a plate-like member provided facing the one end side wall portion of the chamber body. The vapor phase growth apparatus according to claim 4.
The plate-like member that is the rectifying member is provided with a main surface inclined perpendicularly to the gas introduction direction or inclined at 45 ° toward the other end side wall. The vapor phase growth apparatus according to claim 4 or 5,
A vapor phase growth apparatus characterized in that 10 mm ≦ L1 ≦ 50 mm, where L1 is a horizontal distance between the one end side wall portion and the plate-like member. In the vapor phase growth apparatus according to any one of claims 4 to 6,
The gas introduction part is provided on an upper part of the one end side wall part of the chamber body,
The plate member is suspended from the ceiling wall of the chamber body,
When the vertical distance between the ceiling wall portion and the bottom wall portion of the chamber body is L2, the vertical distance between the ceiling wall portion and the gas introduction portion is L3, and the vertical length of the plate-like member is L4. 0.1 ≦ L4 / L2 ≦ 0.5 and 0.2 ≦ L3 / L4 ≦ 1.0.

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