JPS63243285A - Rotating electrode type magnetron etching device - Google Patents

Abstract

PURPOSE:To carry out magnetron etching with high uniformity by providing a means for rotating an etching electrode fitted with a substrate in the plane of a uniform magnetic field in a vacuum vessel. CONSTITUTION:The etching electrode 2 fitted with the substrate 4 is rotated by a driving motor 7 through a rotating shaft 5 and an insulated transmission mechanism 6. A glow discharge is generated between the etching electrode 2 and a counter electrode 3 by the high-frequency power from a high-frequency power source 9, and the substrate 4 is etched. A reactive gas is supplied from the counter electrode 3 through a shower-type gas hole. The glow discharge generated between the electrodes 2 and 3 is confined on the surface of the rotating etching electrode 2 by the uniform magnetic field formed by a pair of rectangular magnetic circuits. The electron in the glow discharge is cyclodially moved on the surface of the etching electrode 2 by the action of the magnetic field, and the ionization efficiency of the neutral atom and molecule is enhanced. By this method, the deviation of the plasma can be compensated, and etching is carried out with high uniformity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotating electrode type magnetron etching device.

[Prior Art] Conventionally, electromagnetic coil type and permanent magnet type are known as magnetron etching devices.

In principle, an electromagnetic coil type magnetron etching device connects a high frequency power source C to one of electrodes A and B placed opposite each other by RFC as shown in Figure 6 of the attached drawings, and generates electricity between these parallel plate electrodes. In order to generate a high frequency discharge, Helmholtz coils D and E with the same magnetization direction are arranged in a pair on both the left and right sides of the parallel plate electrodes A and B, and an alternating current is passed through these coils from an alternating current source to cause a discharge on the substrate G. The device is configured to generate an alternating magnetic field. Since the generated alternating current magnetic field and high frequency electric field are orthogonal to each other, electrons are confined near the etching electrode B, making it possible to form a high-density plasma.

In addition, many magnetron etching devices using permanent magnets have a structure as shown in all 7 figures, in which a pair of permanent magnets K are connected to a high frequency power source H for discharging and are placed on the sides of an etching electrode J supporting a substrate l. placed and etched electrode J
The magnetic field lines cross the surface of the etching electrode J, and are perpendicular to the high-frequency electric field lines emanating from the etching electrode J, so that a magnetron discharge is generated on the surface of the etching electrode J. It is called a stationary static magnetic field type.

In such a conventional magnetron etching device, electrons on the etching electrode move to the left depending on the directions of the electric and magnetic fields, for example, as shown in Figure 8, and collide with neutral gas particles, causing will be ionized.

When electrons collide with neutral particles, ions are generated and secondary electrons are generated, resulting in electron density and discharge voltage characteristics as shown in FIG. Since the plasma is neutral, the ion density, as well as the electron density, will be denser to the left of the etching electrode, and the ion landscape incident on the etching electrode will also increase, and these ions will contribute to the etching of the substrate.

[Problems to be Solved by the Invention] In the conventional Macnetron etching apparatus as described above, as shown in FIG. 9, the plasma density increases in the direction of electron drift, so the etching rate increases. Since the density is proportional to the density of the plasma, the non-uniformity of etching increases. As described above, in the conventional magnetron etching apparatus, it is difficult to perform etching processing with high uniformity due to the bias of plasma generated by the electron drift phenomenon peculiar to magnetron discharge.

It is recognized that this tendency becomes more pronounced as the size of the substrate to be processed becomes larger, particularly in a single-wafer dry etching apparatus.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a rotating electrode type magnetron etching device that has a uniform magnetic field and can perform highly uniform etching processing.

[Means for Solving the Problems] In order to achieve the above object, a rotating electrode type magnetron etching apparatus according to the present invention includes a pair of magnetic field generators that generate a uniform magnetic field within a vacuum container; It is characterized in that it has an etching electrode that is placed in the vacuum container and rotates within the plane of the magnetic field generated by the magnetic field generator.

[Function] According to the rotating electrode type magnetron etching apparatus according to the present invention, since the etching electrode rotates within a highly uniform magnetic field plane formed by a pair of magnetic field generators, it is possible to etch the double-headed regions of the dark and dark parts of the plasma. - The substrate to be soothed passes through the etching process repeatedly, and as a result, the uniformity of etching can be improved.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5 of the accompanying drawings.

FIG. 1 and FIG. 2 show an embodiment of the present invention, in which a disk-shaped rotating etching electrode 2 and a facing type [z3 which also serves as a gas blowout] are arranged parallel to each other in a vacuum chamber 1.
The rotating etching electrode 2 has a substrate 4 to be etched mounted on its upper surface, and is connected to a rotary drive shaft 5 provided through the wall of the vacuum chamber 1, and this rotary drive shaft 5 is an insulated transmission It is driven by a drive motor 7 via a mechanism 6. Also, inside the rotation drive shaft 5, although not shown in the drawing, there is an etching electrode 2 that rotates from a cooling water jacket 8.
The zero rotation etching electrode 2, which is provided with a cooling water passageway extending therein, is also connected to a high frequency power source 9.

vacuum! A pair of rectangular magnetic circuits each consisting of a magnet 10 and a magnetic pole 11 are provided around g1, as shown in FIG. They are positioned equidistantly above and below. This distance X can be, for example, 25 nn as standard. The magnetic circuit can also be made in particular such that the perpendicular magnetic field component is O Gaussian.

In the operation of the illustrated apparatus constructed as described above, an etching electrode w! with a substrate 4 to be etched mounted on the upper surface thereof is used.
2 is rotationally driven at a required speed by a drive motor 7 via a rotational drive @5 and an insulated transmission fJ6. Glow discharge is generated between the rotating etching electrode 2 and the counter electrode 3 by the high frequency power supplied from the high frequency power supply 9, and as a result, the substrate 4 to be etched, which is mounted on the top surface of the rotating etching electrode 2, is etched. be done.

The reactive gas is supplied from the counter electrode 3 through a Java gas hole.

The glow discharge excited between the electrodes 2, 3 can be confined on the surface of the rotating etching electrode 2 by a uniform magnetic field formed by a pair of rectangular magnetic circuits. This magnetic 1%
(for example, about 200 Gauss), the electrons during the glow discharge move cycloidally on the surface of the etching electrode 2. Due to this cycloidal movement of electrons, the ionization efficiency of neutral atoms and molecules is increased, and a dense plasma is formed near the electrode surface, resulting in a so-called magnetron discharge state.
The discharge voltage becomes extremely low. For example, the pressure inside the vacuum chamber 1 is 0.
．． Under the condition of 02tor (RF power density IW/Cl112), the self-bias voltage is about 100V.

As shown in Figure 3, when magnetic lines of force exist in the y direction of a disc-shaped etched electrode, the vertical magnetic field on the electrode is approximately 5
0 Gauss or more, and if the electrode is fixed, the fourth
Although the etching distribution is non-uniform as shown by X'' and yo in the figure, if the vertical magnetic field is 0 Gauss and the electrode is rotated, highly uniform etching can be achieved as shown by xly.

FIG. 5 shows a modified embodiment of the present invention, in which parts corresponding to the embodiments of FIGS. 1 and 2 are designated by the same reference numerals.
is used. The electromagnet 12 is positioned so that its central axis coincides with the surface of the etching electrode 2.

By the way, in the illustrated embodiment, by insulating the counter electrode and applying high frequency power to it,
It is also possible to implement it as a sputtering device or a plasma CVD device, and in that case, the centers of the opposing magnetic poles of the magnetic circuit must be aligned with the opposing electrode surface.

[Effects of the Invention] As explained above, in the rotating electrode type magnetron etching apparatus according to the present invention, the vertical component can be reduced to zero.
Since the etching electrode is rotated within the plane of a uniform Gaussian magnetic field, it is possible to offset the plasma bias caused by electron drift, which is characteristic of magnetron discharge, thereby achieving highly uniform etching processing. Can be done. In addition, compared to a device using a rotating magnetic field, it is possible to provide an extremely practical device in terms of structure and design and cost.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing an embodiment of the present invention, Fig. 2 is a schematic plan view of the device shown in Fig. 1, Figs. 6 and 7 are schematic diagrams showing different examples of the conventional magnetron etching apparatus, and FIG. 8 shows the drift of electrons on etching "S%". An explanatory diagram showing the state, FIG. 9 is a diagram showing the spatial distribution state of electron density and discharge voltage on the surface of the etching electrode. In the figure, 1: vacuum chamber 2: rotating etching electrode 3: counter electrode 4: etching Substrate to be processed 5: Rotation drive shaft 6: Insulated transmission R structure 7: Drive motor 8: Cooling water jacket 9: High frequency power supply 10: Magnet 11: Magnetic pole 12: S magnet Figure 1 Figure 2 Figure 3 Figure 4 Figure 5, ? Figure 6 Figure 7

Claims (1)

[Claims] It is characterized by having a pair of magnetic field generators that generate a uniform magnetic field within the vacuum container, and an etching electrode that is arranged within the vacuum container and rotates within the plane of the magnetic field generated by the magnetic field generators. Rotating electrode type magnetron etching equipment.