JPH03263321A - Microwave plasma processing equipment - Google Patents

Abstract

PURPOSE:To enable uniform treatment of a large wafer, and improve the yield and the quality of a semiconductor device, by arranging a plurality of microwave feeding ports installed on the side surface of a plasma generating chamber, at the relative positions facing a substrate to be treated. CONSTITUTION:Two microwave feeding ports 31, 32 are arranged on one side surface (upper surface) of a plasma generating chamber 5, so as to face a wafer 7 and be positioned relatively on the right and the left of a center point. An reaction gas feeding inlet 10 is arranged at the center position (the center point of one side surface) of two microwave feeding ports. By this constitution, a plurality of microwave feeding ports are arranged in the vicinity of a side wall without complicating an equipment by changing the shape and the arrangement of magnets, so that plasma density distribution is made uniform. Hence a large wafer is uniformly treated with the more uniformly distributed plasma gas.

Description

[Detailed Description of the Invention] [Summary 1] Regarding the improvement of microwave plasma processing equipment such as microwave plasma etching and vapor phase growth, the aim is to uniformly process large wafers. In a microwave plasma processing device that generates cyclotron resonance (ECR) and processes a reactive gas by turning it into plasma, a plurality of microwave waveguides provided on the side of a plasma generation chamber are placed at relative positions facing the substrate to be processed. It is characterized by being arranged.

The method is also characterized in that a reactive gas inlet is provided at the center of the plurality of microwave waveguides arranged at relative positions facing the substrate to be processed.

[Industrial Application Field] The present invention relates to improvements in microwave plasma processing equipment such as microwave plasma etching and vapor phase growth.

As a process technology for semiconductor manufacturing, dry processing has become an extremely important technology for the miniaturization and high integration of semiconductor devices.
Microwave plasma processing apparatuses are widely used that perform processes such as etching and growth by generating tron resonance.

Such microwave plasma processing equipment has the advantage of uniformly turning the introduced gas into plasma, but on the other hand,
As the size of substrates to be processed increases, there is a need for measures to uniformly process the enlarged processing surface.

[Prior Art] Fig. 4 shows a cross-sectional view of the main parts of a conventional microwave plasma processing apparatus, and the symbol 1 in the figure is a microwave waveguide, and the symbol 2 is a microwave waveguide.
is a magnetron, 3 is a microwave inlet, 4 is a ring-shaped coil (magnet), 5 is a plasma generation chamber, 6 is a plasma processing chamber, 7 is a wafer (substrate to be processed), 8, 8'' is a reaction gas inlet .

9 is an exhaust port.

As shown in the figure, the microwave plasma processing equipment connects the magnetron and the plasma generation chamber with a waveguide, and the microwave inlet (microwave transparent window),
Microwaves are introduced into the plasma generation chamber from the microwave inlet, and the resonance between the microwaves and the magnetic field causes the electrons to rotate, and the electrons collide with the reaction gas to turn the reaction gas into plasma. This equipment performs processes such as etching and vapor phase growth. In addition, the magnetic field generated by the coil has a magnetic field gradient that becomes weaker in the wafer mounting direction, and the ionized gas is accelerated in that direction (one direction of the wafer).

Note that the microwave transmission window is a window that allows only microwaves to pass through while vacuum-sealing the inside of the plasma processing chamber, and is made of quartz or arsina. Further, in FIG. 4, two reaction gas inlets 8.8'' are provided, and 8'' indicates an inlet for introducing gas that does not necessarily need to be turned into plasma.

Thus, for example, monosilane (SiH
4) is introduced to decompose the reaction gas turned into plasma = 3 to grow a silicon film, and freon (CF4) is introduced and the silicon layer is etched by the reaction gas turned into plasma. is carried out.

[Problems to be Solved by the Invention] By the way, when performing processing using such a microwave plasma processing apparatus, the shape of the magnetic field (the above example is a so-called diverging magnetic field type in which the magnetic field is weaker in one direction of the wafer) However, there are also cusp magnetic fields, etc.), the arrangement of magnets,
Attempts have been made to adjust the plasma density distribution to make it uniform by changing the ion current density, etc., in order to make it compatible with larger wafers, for example, wafers with a diameter of 8 inches.

However, simply changing the shape of the magnetic field, the arrangement of the magnets, etc. only complicates the apparatus, and there is a drawback that sufficient uniformity of plasma density distribution cannot be obtained for large wafers.

The present invention proposes a microwave plasma processing apparatus aimed at reducing such problems and uniformly processing large wafers.

[Means for solving the problem] The purpose is achieved by a microwave plasma processing apparatus in which a plurality of microwave waveguides provided on the side of a plasma generation chamber are arranged at relative positions facing the substrate to be processed. be done.

In addition, the object can be better achieved by arranging the reactive gas inlet at the center of the plurality of microwave waveguides arranged at relative positions facing the substrate to be processed.

[Effect 1 In other words, conventionally, only one microwave waveguide is provided in the center, so the plasma density is high in the center (
, the plasma density distribution was mountain-shaped, decreasing as it approached the side wall in contact with the coil of the plasma generation chamber.
In the present invention, since a plurality of microwave waveguides are arranged near the side wall, there is an advantage that the plasma density distribution is made uniform (see FIG. 2).

Therefore, - by layer homogeneously distributed plasma gas,
Large wafers can be processed and uniform processing can be achieved.

[Example] Hereinafter, embodiments will be described in detail with reference to the drawings.

FIGS. 1(a) and 1(b) show schematic diagrams of main parts of a microwave plasma processing apparatus according to the present invention, and FIG.
) is a sectional view, and FIG. 1(b) is a sectional view taken along line AA in FIG. 1(a).

Symbols 11 and 12 in the figure are microwave waveguides, 2L 2
2 is the magnetron, 31.32 is the microwave inlet,
4 is a ring-shaped coil (magnet), and 5 is a plasma generation chamber.

6 is a plasma processing chamber, 7 is a wafer, 10. 8'
9 is a reaction gas inlet, and 9 is an exhaust port.

That is, this example is an example in which two microwave introduction ports 31 and 32 are provided on one side (upper surface) of the plasma generation chamber 5 on the left and right sides of the center point, facing the wafer 7. and,
The reactive gas inlet 10 is placed at the center of the two microwave waveguides (the center of the - side). If configured like this, the shape of a magnet.

A uniform plasma density distribution can be achieved without complicating the apparatus by changing the arrangement.

FIG. 2 is a diagram showing the effect of the present invention, where the vertical axis is the plasma density, the horizontal axis is the position in the horizontal direction (parallel to the wafer) of the plasma processing chamber, and the curve I (shown as a solid line) is the first It is a plasma density distribution in the microwave plasma processing apparatus according to the present invention shown in the figure. In addition, the curve ■ (indicated by a dotted line) is the plasma density distribution in the conventional microwave plasma processing apparatus shown in FIG. It is clear that the plasma density distribution is more uniform in this case.

The following FIG. 3 shows a diagram of the main parts of another microwave plasma processing apparatus according to the present invention, and this figure shows a cross section (AA cross section) corresponding to FIG. 1 (b). Figure 1 (a
) is not shown because it is almost the same as FIG. 1(a). As shown: - This example has four microwave inlets 33, 34, 35. ．． 9
In the example in which 6 is provided, the plasma density distribution becomes more uniform.

In the above example, separate magnetrons are provided at each of the plurality of microwave introduction ports, but a method may also be adopted in which a microwave waveguide is led out from one magnetron and branched.

Furthermore, the effects of the present invention can be obtained even if the position of the reaction gas inlet is not central. However, since the reaction gas can be more uniformly dispersed in the plasma generation chamber 5 by locating it at the center, as shown in FIG.

Preferably, the configuration is as shown in FIG.

Furthermore, in the microwave plasma processing apparatus according to the present invention, on the premise that the apparatus becomes complicated, the configuration of the plurality of microwave inlets described above has a shape of a magnet.

Needless to say, if changes in arrangement are added, the plasma density distribution can be made more uniform.

[Effects of the Invention] As is clear from the above description, according to the present invention, it is possible to uniformly process large wafers, for example, wafers with a diameter of 10 inches, thereby improving the yield and quality of semiconductor devices. This will greatly contribute to the

[Brief explanation of drawings]

Figure 1 (aL (b) is a schematic diagram of the main parts of the microwave plasma processing apparatus according to the present invention, Figure 2 is a diagram showing the effects of the present invention, and Figure 3 is another microwave plasma treatment according to the present invention. Figure 4 is a sectional view of the main parts of the conventional microwave plasma processing apparatus. In the figure, 11L12 is a microwave waveguide, 2, 21.22 is a magnetron, 3L 32 33.34.35 .36 is a microwave introduction port, 4 is a ring-shaped coil (magnet), 5 is a plasma generation chamber, 6 is a plasma processing chamber, 107 is a wafer (substrate to be processed), 8.8', 10 is a reaction gas introduction 9 indicates the exhaust port. ■ 132 + Invention a 3 effect reeds T figure 2 figure 4 day moon 1: η・ka 3 Japanese begging my 7D garden 7・U7・
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Claims (2)

[Claims] (1) In a microwave plasma processing device in which microwaves combine with a magnetic field to cause electron cyclotron resonance (ECR) and process a reactive gas by turning it into plasma, multiple microwave waveguides are installed on the side of a plasma generation chamber. A microwave plasma processing apparatus characterized in that an opening is disposed at a relative position facing a substrate to be processed. (2) The microwave according to claim (1), characterized in that a reactive gas inlet is disposed at a center point of a plurality of microwave waveguides arranged at relative positions facing the substrate to be processed. Plasma processing equipment.