JPS58170016A - Plasma etching device - Google Patents

Abstract

PURPOSE:To execute the sputtering and etching of high efficiency to a material to be treated, and to etch the material uniformly by generating an electric field between a cavity type electrode and a plate type electrode by a high-frequency power supply while forming a closed type magnetic field, which issues from the surface of the plate type electrode and enters into the surface, by a magnet. CONSTITUTION:The plate type electrode 20 consisting of a conductive nonmagnetic substance is disposed into a vacuum vessel 2 while being opposed to the opening section 1b of the cavity type electrode 1, and high-frequency voltage is applied between the plate type electrode 20 and the cavity type electrode 1. Accordingly, plasma is generated in the cavity type electrode 1, gas ions are attracted to the plate type electrode 20 and collide with the surface of the material to be treated A placed onto the plate type electrode 20, and the gas ions are sputtered and the material is etched. The magnet is arranged between the back of the plate type electrode 20 and the vacuum vessel 2, and the magnetic field which issues from the surface of the plate type electrode 20 and enters into the surface is formed by the magnet 21.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a plasma etching apparatus.

The present invention relates to a plasma etching apparatus for uniformly and efficiently etching a workpiece in the production of semiconductor integrated circuits and the like.

[Technical background of the invention]

Figure 1 shows a conventionally used plasma etching apparatus, in which a cavity-shaped electrode l having an internal space /a and an opening /b is attached to a vacuum container (9), and the inner wall of this vacuum container (2) is attached. A high-frequency discharge is generated between the cavity electrode and the vacuum container by placing an electric current on the object to be processed, and using the rectifying effect of the discharge, freon (OFa) = oxygen (
The surface of the object to be processed is etched by forming gas ions such as ions. The vacuum container is attached to the insulating member 3.
The periphery of the opening 160 is recessed by a dark space shielder, and the DC interrupting capacitor 5
, a matching coil 6 and a matching capacitor 7, and a high square frequency cable l.

io is a shield that prevents high frequency leakage from the circuit part. Etching gas is supplied to and discharged from the vacuum container and the hollow electrode using a needle valve.

/J group.

When high frequency discharge is performed with this device, it is 1 g! sinus shaped electrode
The gas inside is ionized and plasma is generated, while the vacuum vessel Jll becomes a dark space. Therefore, when the potential of the vacuum container becomes negative, gas ions are attracted to the vacuum container and collide with the surface of the workpiece on the vacuum container.
Etching is performed.

[The essence of background technology]

With this Toki device, etching is fast! #Lt-In order to increase the speed, a method is adopted in which high-frequency power is increased to generate high-density plasma.

However, when the high-frequency power is increased, the DC voltage and high-frequency voltage applied to the object to be processed increase, and the insulating member 3
Not only does it require an increase in the withstand voltage of the circuit, but it also has the disadvantage that the circuit itself becomes larger as the high-frequency power increases.

C.Object of the Invention The present invention has been made in view of the following drawbacks of the prior art, and an object of the present invention is to provide a plasma etching apparatus with a simple structure that can perform uniform etching at a high etching speed. purpose.

[Summary of the invention]

In order to achieve this object, in the present invention, a flat plate electrode made of a non-magnetic material is disposed inside the vacuum container, facing the hollow electrode attached to the wall of the vacuum container.

A magnet is arranged on the back surface of the flat electrode to cause the discharge between the flat electrodes and to form a closed magnetic field that exits from and enters the surface of the flat electrode.

The magnet is scanned along the bottom surface of the flat electrode.

[Embodiments of the invention]

An embodiment of the present invention will be described below based on the accompanying drawings.

FIG. 2 is a block diagram of a plasma etching apparatus according to this embodiment, and the same reference numerals as in FIG. 1 indicate the same elements. In the configuration shown in FIG. 2, a plate-shaped electrode is provided which forms a discharge gap in relation to the cavity-shaped electrode, which is different from the device shown in FIG.

In addition to arranging a wet scanning magnet on the back surface of this flat plate electrode, Go's method of circulating cooling water inside the flat plate electrode is similar to the method used to store the workpiece that is placed on the top of the electrode. This was done to cool it down.

That is, a flat plate electrode made of a conductive non-magnetic material is placed in a vacuum container facing the opening /b of the hollow electrode /, and between the flat electrode X and the hollow electrode 1. Apply high frequency voltage. As a result, plasma is generated within the hollow electrode X, gas ions are attracted to the flat plate il&r, and collide with the surface of the workpiece placed on the flat electrode X, thereby performing sputter etching.

Back side of flat electrode and vacuum IF! A magnet is placed between the magnet and the flat electrode X, and a closed magnetic field is formed that exits from and enters the surface of the flat plate electrode X. In the part where the magnetic field of the magnetic field and the electric field between the hollow electrode and the flat electrode are perpendicular to each other.

Electrons ionized by high-frequency discharge generate a high-density plasma that does not cause magneto motion due to the Lorentz force, and this high-density plasma causes the object to be processed covered with the flat electrode core a to be Performs highly efficient sputter etching. In this way, if a magnetic field is generated by the i-gnet 21, a higher density plasma will be generated than if only an electric field is used, and the etching speed of the object to be processed will be several times faster than in the apparatus shown in the figure. .

Here, since only the area below the plasma track of the workpiece 5 is etched, in order to uniformly etch the entire workpiece A, it is necessary to apply a magnetic col to the workpiece AK.
need to be scanned. Therefore, as shown in Figure 3, it was placed in a vacuum container.

The magnet 21 is scanned from side to side along the back surface of the flat wL pole by a scanning mechanism (not shown).

As a result, the object A to be processed is etched uniformly. In addition, the scanning mechanism of Magnetco/ is as follows.

It is sufficient to use known mechanical or vacuum means.

Further, when the object to be processed is etched at high speed as described above, the temperature of the object to be processed increases due to the collision energy of gas ions to the object A and the thermal radiation of the plasma. %K, when etching a heat-treated object such as a semiconductor pellet coated with photoresist,
Since the human power is determined due to the temperature rise, it is necessary to suppress the human power.Therefore, the flat electrode X is cooled by circulating cooling water B inside the flat electrode x, By suppressing the temperature rise of the object to be processed that is brought into close contact with the electrode, high-speed etching can be performed without reducing human power. Note that other methods such as air cooling may be used to cool the object to be processed, but if the above-mentioned cooling water method is adopted and the flat electrode is grounded, this electrode There is no need to insulate it from others, and the object to be processed can be efficiently cooled with a compact structure.

〔Effect of the invention〕

As explained above, in the present invention, an electric field is generated between the cavity electrode and the flat electrode by a high-frequency power source, and a closed-shaped electric field is generated by the magnet that comes out from the surface of the flat electrode and enters the surface. By forming a magnetic field tube, a high-density plasma is generated in the area where the field and the magnetic field intersect at right angles, and this high-density plasma generates a high Efficient sputter etching can be performed, and the etching speed of the object to be processed is therefore far greater than with conventional devices of this type.Moreover, the magnet is scanned along the back surface of the flat electrode.

Etching is done uniformly. Furthermore, since the magnet can be grounded, there is no need to insulate the scanning mechanism of this magnet from other parts, simplifying the structure of the multi-scanning mechanism. Even when a cooling means is added to the shaped electrode itself, the flat electrode can be grounded, so there is no need to insulate the cooling means, and the structure of the cooling means can be simplified.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional plasma etching system;
The figure is a configuration diagram of a plasma etching apparatus according to an embodiment of the present invention, and FIG. 3 is a plan view for explaining the scanning method of the magnet in FIG. 2. C...Cavity electrode, C...Vacuum container, D...High frequency power supply, 〃...Flat electrode, -I...Magnet. Applicant's agent Kiyoshi Inomata 75 Engraving of the drawings (no changes to the content) Figure 1 Figure 2 Figure 10 Figure 3 Procedural amendments May 11, 1980 Commissioner of the Japan Patent Office Shima 1) Haruki Tono 1, of the case Indication: 1982 Patent Application No. 52558 2 Name of the invention Plasma etching device 3 Person making the amendment Relationship to the case Patent applicant Tokuda Seisakusho Co., Ltd. 7 Subject of the amendment □ Full text of the specification and drawings 8, Contents of correction

Claims (1)

[Claims] A discharge occurs between a cavity-shaped electrode having a good internal space, which is attached to the wall of a vacuum container in which a predetermined gas is contained in a state close to vacuum, and the cavity-shaped electrode, which is disposed within the vacuum vessel. a high-frequency power source that supplies a high-frequency voltage between the front V-shaped cavity electrode and the flat electrode; and a high-frequency power source that supplies a high-frequency voltage between the front V-shaped electrode and the flat electrode; A plasma etching apparatus comprising: a magnet forming a closed magnetic field that exits from the substrate and enters the surface, and the magnet is scanned along the back surface of the flat electrode.