JPH03284844A - Bath for wet-treatment of substrate - Google Patents

Abstract

PURPOSE:To have distances between a plurality of substrates uniform, have the flow of chemical liquid uniform and facilitate uniform etching by a method wherein a table on which the substrates are placed is inclined and the placed substrates are inclined to the same direction. CONSTITUTION:An inner container 9 is placed in an outer container 1 and filled with chemical liquid 2. The chemical liquid 2 overflowing the inner container 9 stays between the outer container 1 and the inner container 9. Further, an inclined table 11 is provided above the outer container 1 and inside the inner container 9 and semiconductor substrates 5 hung by a Teflon hanger 4 are placed on the inclined table 11. A filter 7 and a pump 8 are connected to the containers with pipes 6 and the chemical liquid 2 staying between the outer container 1 and the inner container 9 is supplied to the inner container 9 by the pump 8. The chemical liquid 2 is filtered and circulated through the filter 7. With this constitution, all the semiconductor substrates 5 are inclined to the same direction and, further, distance between the substrates 5 can be uniform, so that the chemical liquid 2 can be made to flow smoothly and brought into contact with the semiconductor substrates 5 uniformly. For instance, if this constitution is applied to etching for adjustment of the thickness of films built up on the semiconductor substrates, the variation of the film thickness can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a wet treatment bath for substrates, and its purpose is to make a film grown on, for example, a semiconductor substrate uniform.

BACKGROUND OF THE INVENTION When manufacturing a semiconductor substrate, it is necessary to uniformly etch a film grown on the semiconductor substrate in order to reduce the parasitic capacitance of a capacitor and to prevent bleeds from occurring on the semiconductor substrate. A conventional wet processing tank for semiconductor substrates will be described below.

FIG. 3 shows a conventional wet processing bath for semiconductor substrates.

In FIG. 3, 1 is an outer container, 2 is a chemical solution, 3 is a stand, 4 is a Teflon hanger, 5 is a semiconductor substrate, 6 is piping, 7 is a filter, 8 is a pump, and 9 is an inner container.

The operation of the wet processing tank for semiconductor substrates configured as described above will be described below.

First, as shown in FIG. 3, an inner container 9 is installed inside the outer container 1, and the inner container 9 is filled with the drug solution 2. The drug solution 2 overflowing from the inner container 9 is accumulated between the outer container 1 and the inner container 9.

Furthermore, there is a stand 3 in the upper part of the outer container 1 and in the inner container 9, and a semiconductor substrate 5 held by a Teflon hanger 4 is installed in the third upper part. In addition, a filter 7 and a pump 8 are connected by a pipe 6, and the chemical solution 2 accumulated between the outer container 1 and the inner container 9 is supplied into the inner container 9 by the pump 8, and the drug solution 2 is circulated and filtered through the filter 7. However, in the above conventional configuration, as shown in FIG. 4, the inclination direction of the semiconductor substrate 5 is not constant, so the intervals between them are uneven, and the flow of the chemical solution 2 in contact with the semiconductor substrate 5 is also uneven. . In particular, the semiconductor substrate 5 indicated by f in FIG. 4 obstructs the flow of the chemical solution 2. For this reason, the film 10 grown on the semiconductor substrate 5 has become a cause of variations among the five semiconductor substrates and within the plane.

FIG. 5 shows the etching accuracy of the conventional example shown in FIGS. 3 and 4. The same figure (a) shows the semiconductor substrate Il! The distribution of the film thickness on the semiconductor substrate between the semiconductor substrates after the etching process for each of the steps No. 11 to N117 is shown in FIG.
7 shows the in-plane film thickness distribution of an arbitrary semiconductor substrate of No. 7. It can be seen from FIGS. 5(a) and 5(b) that there are variations in the film thickness on the semiconductor substrate.

Note that FIG. 5(C) shows the measurement position on the semiconductor substrate in FIG. 5(b).

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a wet processing tank for semiconductor substrates that uniformly etches a film grown on a semiconductor substrate.

Means for Solving the Problems In order to achieve this object, the substrate processing tank of the present invention has a table on which a substrate such as a semiconductor substrate is placed, which is tilted,
The substrates placed on this table are tilted in the same direction.

Function: With this configuration, the spacing between the plurality of substrates becomes uniform and the flow of the chemical becomes uniform, so that, for example, in an etching process, a film grown on the substrate can be etched uniformly.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a wet processing tank for semiconductor substrates. In Figure 1, 1 is the outer container, 2 is the drug solution, and 4 is the outer container.
5 is a Teflon hanger, 5 is a semiconductor substrate, 6 is piping, 7 is a filter, 8 is a pump, 9 is an inner container, and 11 is a tilt table.

The operation of the wet processing tank for semiconductor substrates configured as described above will be described below.

First, as shown in FIG. 1, an inner container 9 is installed in an outer container 1, and the inner container 9 is filled with a medical solution 2. The chemical solution 2 overflowing from the inner container 9 is transferred to the outer container 1 and the inner container 9.
It's accumulated in between. Further, there is a tilting table 12 above the outer container 1 and inside the inner container 9, and a semiconductor substrate 5 held by a Teflon hanger 4 is installed on the top of the tilting table 11. In addition, a filter 7 and a pump 8 are connected by a pipe 6, and the chemical solution 2 accumulated between the outer container 1 and the inner container 9 is supplied into the inner container 9 by the pump 8, and the drug solution 2 is circulated and filtered through the filter 7. It is carried out.

As described above, according to this embodiment, all the semiconductor substrates 5 held on the Teflon hanger 4 can be tilted in the same direction by providing the tilt table 11 as shown in FIG. Therefore, the intervals between the semiconductor substrates 5 can be made uniform.

As a result, the chemical liquid 2 flows smoothly and contacts the semiconductor substrate 5 uniformly.

FIG. 6 shows the etching accuracy of this example. Figure (a)
shows the distribution of the film thickness on the semiconductor substrate between the semiconductor substrates after the etching process for each of the semiconductor substrate teeth 1 to 17;
) shows the film thickness distribution within the plane of an arbitrary semiconductor substrate of semiconductor substrate teeth 1 to 17 (same position as in FIG. 5C). Comparing Fig. 5 and Fig. 6, it is found that the variation in film thickness is smaller in the embodiment of the present invention than in the conventional etching accuracy Fig. 5(a) and Fig. 5(b). I understand that.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be further modified and implemented in various ways.

For example, in the above embodiment, the case where the present invention is applied to etching to adjust the thickness of a film grown on a semiconductor substrate has been described, but it can also be used for etching treatment to adjust the thickness of a semiconductor substrate. In short, the present invention is a wet processing tank that can be applied when the liquid that comes into contact with the semiconductor substrate depends on whether it is uniform or uneven, and therefore it is effective not only for etching but also for cleaning processes such as washing with water. It is.

Furthermore, if the liquid that comes into contact with the semiconductor substrate could be made even, the groove spacing of the Teflon hanger could be widened, and the structure of the processing tank could be changed.
For example, it goes without saying that the angle of the tilt table, the material, the supporting method, the number, size and angle of holes, etc. can be selected as appropriate.

Effects of the Invention As is clear from the above explanation, the present invention realizes a wet processing tank for substrates that can significantly improve processing accuracy by tilting the table to make the liquid in contact with the substrate uniform. can.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a substrate wet processing tank according to an embodiment of the present invention, FIG. 2 is a partially enlarged sectional view of FIG. 1, and FIG. 3 is a sectional view of a conventional substrate wet processing tank. Figure 4 is the third
5(a) and 5(b) are diagrams showing the conventional etching accuracy, FIG. 5(C) is a diagram showing the film thickness measurement position on the semiconductor substrate, and FIG. 6(a) is a partially enlarged view of the figure. ) and (b) are diagrams showing the etching accuracy of a substrate wet processing bath according to an embodiment of the present invention. 1... Outer container, 2... Chemical solution, 3...
...stand, 4...Teflon hanger 5...
...Semiconductor substrate, 6...Piping, 7...
・Filter, 8...Pump, 9...
Inner container, 10... Growth film, 11... Inclined table.

Claims (1)

[Claims] 1. A wet processing tank for substrates, characterized in that an inclined table is provided in a chemical solution container, and a plurality of substrates placed on the table are inclined in the same direction.