JPH0670979B2 - Vapor phase growth equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vapor phase growth apparatus, and more particularly to a vapor phase growth apparatus in which a reaction vessel is set upright.

[Conventional technology]

FIG. 4 shows a conventional vapor phase growth apparatus. This type of vertical vapor deposition apparatus is used for various film formations, and the Si epitaxial growth will be described below. The single crystal substrates 5 are held in the substrate holder 4 so as to be stacked horizontally at a certain interval and heated to about 900 ° C. to 1200 ° C. under reduced pressure, and the surface of the substrate 5 is covered with silane such as dichlorosilane (SiN ₂ Cl ₂ ). A system gas, hydrogen (H ₂ ) and a doping gas were introduced for epitaxial growth.

The reaction container has a double structure, and the nozzle tube 7 is used to supply the reaction gas to the rotating single crystal substrate 5 which holds the vacuum in the outer tube 1. The reaction gas is discharged through a number of gas discharge holes 10 provided on the wall surface of the inner pipe 2.

[Problems to be solved by the invention]

In the above-described conventional vapor phase epitaxial growth apparatus, the reaction gas discharge holes 10 provided in the nozzle tube 7 for supplying the reaction gas to the substrate crystal 5 are present on the cylindrical surface of the nozzle tube 7 in only one row in the longitudinal direction. Therefore, there is a drawback that the reaction gas discharged from the nozzle tube 7 is supplied only to a narrow region in the horizontal plane including the reaction gas discharge hole 10 and the substrate crystal 5.
In order to make the film thickness on the substrate surface uniform by the vapor phase growth method, it is necessary to uniformly supply the reaction gas to a large area on the substrate surface, but the substrate crystal 5 has a large diameter and the area of the substrate surface is large. However, in the conventional apparatus, it becomes difficult to make the reaction gas uniform over the entire area of the substrate surface, and the film thickness within the substrate surface cannot be made uniform.

[Means for solving problems]

The vapor phase growth apparatus of the present invention holds a plurality of vapor phase growth substrates in an inner tube so as to be horizontally stacked at a predetermined interval, and the plurality of gas phase growth substrates are provided from a nozzle tube having a plurality of gas discharge holes. A gas is caused to flow substantially parallel to each vapor phase growth surface of the vapor phase growth substrate, and the gas is exhausted from the inside of the inner tube through a large number of gas exhaust ports provided on the wall surface of the inner tube itself. A vapor phase growth apparatus for performing vapor phase growth of a film on a vapor phase growth surface, wherein the gas discharge holes are provided in a plurality of rows in a longitudinal direction of the nozzle tube on a side surface of the nozzle tube on the side of the vapor phase growth substrate.
The gas released from the gas release holes in the plurality of rows is made to flow radially spread over the vapor phase growth surface, so that the gas is uniformly supplied to the surface of the vapor phase growth substrate. Characterize.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 (a) is a vertical cross-sectional view of a vapor phase growth apparatus according to an embodiment of the present invention, FIG. 1 (b) is a view showing a nozzle tube 7, and FIG. FIG. 1 is a sectional view taken along the line AA ′ of FIG. This apparatus is provided with a pedestal 3 for supporting the apparatus, a reaction tube having a double tube structure including an outer tube 1 and a cylinder 2, a substrate holder 4 for holding a single crystal substrate 5, a resistance heating furnace 6 and a reaction gas. It is composed of the nozzle tube 7. The reaction gas is ejected from a cylindrical nozzle tube 7 and is exhausted from an exhaust port 9 through a gas exhaust port 8 provided on the inner wall surface of the inner tube.

The nozzle tube 7 is provided with a large number of reaction gas discharge holes 10 as shown in FIG. 1 (b). Since the reaction gas discharge holes 10 are provided in a plurality of rows (3 rows in FIG. 2) on the cylindrical surface of the nozzle tube 7 facing the substrate 5, the reaction gas ejected from the nozzle tube 7 is horizontal. It is radially expanded around the nozzle tube 7 and supplied. Therefore, even when film growth is performed on the large-diameter substrate crystal 5, it is possible to make the film thickness uniform in the substrate surface.

An example of growing an epitaxial film using the vapor phase growth apparatus according to this example will be described below. Board holder 4 has a diameter of 15
100 pieces of 0 mm silicon single crystal substrates 5 are set at intervals of 8 mm, the substrate holder 4 is rotated at a rotation speed (5 rpm) of 5 rotations per minute, and the temperature in the reaction tube is adjusted to 10 by a resistance heating electric furnace.
It was set to 50 ° C. 20l / min to more H ₂ nozzle tube 7, the SiH ₂ Cl ₂ 20
Flowing 0 ml / min, PH ₃ at 2 ml / min, pressure 5 torr and N type silicon epitaxial film 5 μm on silicon single crystal substrate 5.
I grew it. This result will be described in comparison with the result when an epitaxial film is grown by the conventional apparatus shown in FIG. FIG. 2 shows the in-plane film thickness distribution of a substrate when grown on a substrate 5 having a diameter of 150 mm using the conventional growth apparatus and the growth apparatus of the present invention. In the case of the conventional device, the thickness of the epitaxial film is about ± 5% in the central area of 60 mmφ, and the thickness decreases toward the outer periphery, and the in-plane film thickness distribution including the peripheral area is It was ± 40%.
On the other hand, in the apparatus of the present invention, the uniformity of the in-plane film thickness was remarkably improved, and a favorable value of ± 4% in the in-plane film thickness distribution was obtained. In addition, a good result was obtained in which the in-plane resistance distribution was about ± 3%.

FIGS. 3A to 3C are explanatory views of another embodiment of the present invention. Although the cylindrical tube is used as the nozzle tube 7 in the above-described Example 9, it is shown that the present invention is not limited to the cylindrical tube. In FIG. 3, the nozzle tube 7 is a polyhedron tube having three sides on the side facing the substrate, and each side has a plurality of gas discharge holes 11 in a row. For this reason, the gas flow path lines from the respective surfaces spread radially on the substrate surface.

With the nozzle tube according to this embodiment, a silicon epitaxial film can be grown on a substrate crystal having a diameter of 150 mmφ under the same conditions as in the embodiment, and the film thickness distribution in the substrate surface can be suppressed to about ± 4%. I got the same result as.

〔The invention's effect〕

As described above, according to the present invention, when a plurality of reaction gas discharge holes provided in the nozzle tube of the vapor phase growth apparatus show the gas discharged from each discharge hole by a single gas flow path line, on the substrate surface. The reaction gas is uniformly supplied to almost the entire region of the substrate surface such that the plurality of flow path lines radially spread around the nozzle tube. As a result, there is an effect that the film thickness within the surface of the substrate is made uniform.

Further, although silicon epitaxial growth has been described above as an example, the vapor phase growth apparatus of the present invention can be applied to the formation of various oxide films, nitride films, polysilicon films, amorphous silicon films and the like. Furthermore, the heating method is not limited to resistance heating, and it is also possible to use lamp heating, induction heating, or the like.

[Brief description of drawings]

FIG. 1 (a) is a vertical sectional view of a vapor phase epitaxial growth apparatus according to an embodiment of the present invention, FIG. 1 (b) is a front view of a nozzle tube according to an embodiment of the present invention, and FIG. A in Figure 1 (b)
A'line sectional view, FIG. 2 is a diagram showing the in-plane film thickness distribution of an embodiment of the present invention, and FIG. 3 (a) is a sectional view of a nozzle tube used in the second embodiment of the present invention. 3 (b) is a front view of a nozzle tube used in the second embodiment of the present invention, FIG. 3 (c) is a sectional view taken along the line AA 'of FIG. 3 (b), and FIG. 4 (a). ) Is a vertical sectional view of a conventional vapor phase epitaxial growth apparatus, FIG. 4 (b) is a front view of a conventional nozzle tube, and FIG. 4 (c) is a fourth view.
It is a BB 'line sectional view of a figure (b). 1 ... Outer tube, 2 ... Inner tube, 3 ... Stand, 4 ... Substrate holder, 5 ... Single crystal substrate, 6 ... Resistance heating furnace, 7 ... Nozzle tube, 8 ... Gas discharge hole, 9 ... Exhaust port, 10 ... Gas release hole.

Claims (4)

[Claims] 1. A plurality of vapor phase growth substrates are held inside an inner tube so as to be horizontally stacked at predetermined intervals, and the plurality of vapor phase growth substrates are provided from a nozzle tube having a plurality of gas discharge holes. The gas is made to flow substantially parallel to each vapor phase growth surface of
A vapor phase growth apparatus for vapor-depositing a film on the vapor phase growth surface by discharging gas from the inside of the inner tube through a large number of gas exhaust ports provided on the wall surface of the inner tube itself, The gas discharge holes are provided in a plurality of rows in the longitudinal direction of the nozzle tube on the side surface of the nozzle tube on the side of the vapor phase growth substrate, and the gas discharged from the gas discharge holes of the plurality of rows is on the gas phase growth surface. The gas phase growth apparatus is characterized in that the gas is uniformly supplied to the surface of the vapor phase growth substrate by spreading the gas radially. 2. The vapor phase growth apparatus according to claim 1, wherein the nozzle tube is a cylindrical tube. 3. The vapor phase growth apparatus according to claim 1, wherein the nozzle tube is a polyhedral tube. 4. The vapor phase growth apparatus according to claim 1, wherein the vapor phase growth is silicon epitaxial growth.