JPS61217573A - Electric discharge device for vacuum treatment - Google Patents

Abstract

PURPOSE:To provide an electric discharge device for vacuum treatment which makes possible the high-speed and efficient treatment with high uniformity and high quality by providing respectively a magnetic field generating means along the surface of tan electrode provided in a vacuum vessel and a means for setting a Miller magnetic field to the edge part of said electrode. CONSTITUTION:The inside of the vacuum vessel 10 is evacuated to a prescribed pressure (for example, 10<-8> Torr) and thereafter a gas such as Ar is introduced therein to a prescribed pressure (for example, 10<-2> Torr) by which the pressure is regulated. A Helmholtz power source 34 is then operated to generate the magnetic field and thereafter an electric power source 25 is operated to intersect orthogonally the magnetic field generated on the surface of the electrode 23 with the magnetic field, thereby generating the high-density plasma. The plasma is confined near the electrode plate 23 by the Miller magnetic field at the edge of the plate 23. Sputtering on the surface of an object 29 to be treated is made possible if the object 29 is used in place of the object 24 to be treated and a sputtering material is placed in place of the electrode plate 23. As a result, the plasma is confined with high density in a uniform distribution on the surface of the object to be treated.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a discharge device for vacuum processing, and in particular to a sputtering device, an etching device, and a plasma CVD (hereinafter referred to as pcVD)
It is extremely effective when applied to equipment that performs various types of processing in vacuum using electrical discharge or plasma.

(Prior art and its problems) In these devices, electrodes are always placed (regardless of whether inside or outside the vacuum chamber) in order to perform a predetermined process.

Plasma is generated at a predetermined location near the electrode, and a predetermined process is performed in or near the plasma.

This plasma is distributed at a predetermined location with a predetermined density distribution (
It is desired to obtain a predetermined density (often a high density) with a uniform density distribution in many cases. To this end, many efforts have been made in the past.

Many proposals have been made to date. In sputtering equipment, expensive target materials are utilized at the highest possible rate (
In addition, in the etching equipment, the plasma is sputtered so that the surface of the object to be etched (sample to be etched) has a predetermined treatment distribution (uniform in most cases). Even in CVD, it is desired to obtain a predetermined deposition distribution (uniform in many cases) on the surface of the object to be processed, but there is no complete device that can provide sufficient satisfaction.It is desirable to reduce power consumption. Only in certain places (often only near the surface of the electrode)
However, with the technology available to date, it is impossible to obtain plasma that spreads to locations other than the desired location. The problem is not only an increase in power consumption, but also the occurrence of impurities in a given process (for example, in sputtering equipment, the material of the vacuum chamber may cause impurities to form in the film). (This also causes similar problems in etching, plasma CVD, etc.), and in severe cases may damage the equipment.

(Object of the Invention) The object of the present invention is to eliminate all or at least some of the drawbacks of the conventional apparatuses mentioned above, and to provide a vacuum processing apparatus which enables processing with high uniformity, high quality, high speed and efficiency. The purpose is to provide a discharge device.

(Structure of the Invention) The present invention provides a vacuum container for evacuating the inside to a predetermined pressure, an evacuation system for the vacuum container, an electrode provided inside the vacuum container, a means for setting a magnetic field along the surface of the electrode, and a device for setting a magnetic field along the surface of the electrode. The above object has been achieved by a discharge device for vacuum processing which is equipped with means for setting a mirror magnetic field at the edge of the electrode.

(Example) Next, this invention will be explained in detail using an example with reference to drawings. In the embodiments shown in FIG. 1 (front sectional view), FIG. 2, and FIG. 3 (plan view and front view showing the basic configuration of the invention extracted from FIG. 1), 10 is a vacuum container, 11 is a container, 12 is an insulator that also serves as airtight, 13 is an exhaust pipe connected to an exhaust system or pressure adjustment system (not shown), 20 is an electrode, and 21 is an inlet pipe (for introducing refrigerants such as water, electricity, etc.) Introduce).

22 is an insulating plate, 23 is an electrode plate (in this embodiment, it is a flat plate, but a single curved plate may be used), 24 is an object to be processed, 25 is a power source,
Reference numeral 29 denotes an object to be processed placed elsewhere (drawn at the knee to mean inside or near the plasma). 30 is a means for setting a magnetic field, 31 (31a and 31b) and 32 (3
2a and 32b) are pairs of Helmholtz coils. 33 is a mirror magnetic field setting means having a ring shape,
331 is a magnetic material, and 332 is a non-magnetic material, and a large number of both are placed alternately so that it is easy to pass the lines of magnetic force toward the center of the ring, but difficult to pass in the circumferential direction. 34
is the Helmholck coil power supply.

35 and 36 indicate typical lines of magnetic force. Reference numeral 35 indicates parallel lines of magnetic force extending onto the surface of the electrode plate 23, and reference numeral 36 indicates lines of magnetic force that are originally parallel but are bent at the edge by the mirror magnetic field generating means 33 to produce a mirror magnetic field.

This device operates as follows. First, the inside is evacuated to a predetermined pressure (for example, 10-' Torr), and then a predetermined gas (for example, argon or silane) is introduced to a predetermined pressure (for example, 10-2 Torr) to adjust the pressure. After activating the Helmholtz coil power source 34 to generate a magnetic field, the power source 25 is activated, and the electric field and magnetic field generated on the surface of the electrode plate 23 are perpendicular to each other, generating high-density plasma. The generated plasma is confined near the electrode plate 23 by the mirror magnetic field at the edge of the electrode plate 23. If the object to be processed 29 is used instead of the object to be processed 24 and a sputtering material (for example, aluminum) is placed in place of the electrode plate 23, sputtering can be performed on the surface of the object to be processed 29, and the gas can be chemically active gas (for example, CF or plasma CV for etching)
In the case of D, plasma etching and plasma CVD can be performed by introducing SiH from an introduction system not shown.

Reactive ion etching (hereinafter referred to as RIE) can be performed by using the object to be processed as 24, excluding 29, and introducing a predetermined chemically active gas (for example, CF4).

In this way, uniform plasma is generated and contained only near the electrode and along its surface, so in the case of sputtering, material is not consumed locally, but is consumed uniformly over the entire surface. This will significantly improve the utilization rate. Impurities such as those from the vacuum container are not mixed in, and power consumption is also reduced. The sputtering speed also becomes faster.

In the case of etching, it is possible to uniformly etch the surface of the object to be processed, and exhibits an excellent effect in the manufacture of VLSIs, for example.

Damage caused by contamination with impurities is reduced, and since power consumption is low, there is less heating of the object to be processed, the electrode, and the vacuum container. Etching speed is high. Similarly, in the case of plasma CVD, plasma CVD is fast, contains few impurities, and has a small temperature rise.
We will get method D.

The embodiments shown in FIGS. 1, 2 and 3 show the basic structure of the present invention, and once this basic understanding is understood, many variations can be created. For example, in Figure 1.

Another method is to provide another vacuum chamber on the left side and take the object 24 or 29 in and out as shown by arrow 14, or to create a continuous device in which substrates are continuously fed (and taken out at the same time) by setting up multiple vacuum chambers. For that purpose, we can design and incorporate various input devices such as water, electricity, introduced gas, etc. and measuring devices at one position as we wish, and create many kinds of useful devices.

In addition, in FIG. 2 of the embodiment, two pairs of Helmholtz coils are used, and the phase of the current supplied from the power supply 34 to each coil is shifted as shown in 34A and 34B schematically there, so that the magnetic field is inside the surface of the electrode plate 23. However, this is effective with just one coil, or three pairs of coils that apply three-phase alternating current may be used, or the magnetic field is fixed and the electrode 2 is rotated around the axis 26. It may be rotated around. Some or all of these may be combined. Furthermore, various design improvements can be made around the electrode 23. For example, alumina, Teflon, etc. may be used for the insulating plate 22, but methods used in conventional devices of this type, such as using vacuum instead of an insulator and surrounding it with a shield, may also be used. good. The shape of the electrode does not necessarily have to be disc-shaped, and various shapes can be determined as necessary.

FIG. 4 (corresponding to FIG. 2) shows another embodiment. In this embodiment, the mirror magnetic field setting means 3
3 is in the shape of a rod instead of a ring as shown in Figure 2.

FIG. 5 (corresponding to FIG. 3) shows yet another embodiment. A composite mirror magnetic field setting means is used in which a large number of mirror magnetic field setting means (shown in cross section) such as annular mirror magnetic field setting means 333, 334, 33 are combined. As shown above, various methods are possible for setting the mirror magnetic field.

Other embodiments are shown in FIG. 6 (perspective view of the main part) and FIG. 7 (front sectional view of a part thereof). In this embodiment, a magnetic field setting means 37 consisting of permanent magnets 37c, 37d and a yoke 370 is used. Furthermore, another magnet and a yoke 38 in the form of an inverted version of 37 may be provided above this to improve the magnetic flux density at the center of the electrode 23 and at the same time to make the lines of magnetic force and the electrode surface more parallel. These include, for example, patent application No. 58-18563 filed by the same applicant as the present application.
A number of systems can be used to good effect, such as those shown in 8 R Discharge Reactor. Further, the electrode 23 is connected to the shaft 2
You can also rotate it around 6.

The magnetic field setting means 37 may be rotated, or both may be rotated in opposite directions or in the same direction at different angular velocities.The mirror magnetic field setting means is the mirror magnetic field setting means 335 shown in FIG. You can also set it like this. This is electrode 23
The same as the mirror magnetic field setting means 33 is added to the insulating section of the mirror magnetic field setting means 33.

Another embodiment is shown in FIG. 8 (a front view of the main part) and FIG. 9 (a side view of a part thereof). In this embodiment, in order to process a large object to be processed, a large number of large magnetic field setting means 37 are formed in a caterpillar shape as shown in FIG.
This is an example of moving in the direction of. In this case, magnet 37c,
A mirror magnetic field is created by pointing 37d upward. FIG. 10 shows another embodiment. In this embodiment, magnetic field setting means 30. The mirror magnetic field generating means 33 and the electrode 23 are arranged coaxially. Although the electrode 23 is shown to have a cylindrical shape, it may have a rectangular tube shape in order to place a planar object 24 thereon.

FIG. 11 shows another embodiment. In this embodiment, the object to be processed 24 and the electrode 23 are coaxially arranged outside the coaxial magnetron. 36 is a mirror-like line of magnetic force. In this case as well, it can be made into a rectangular tube shape.

Although various embodiments have been given above, it goes without saying that these do not have a limiting meaning and that many modifications are possible.

(Effects of the Invention) The present invention has the effect of confining plasma at a high density with uniform distribution on the surface of an object to be treated, thereby enabling highly uniform, high quality, high speed, and highly efficient discharge reaction treatment.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of an embodiment of the present invention. 2 and 3 are a plan view and a front view showing the basic components of the invention extracted from the apparatus shown in FIG. 1. FIG. 4 is a diagram similar to FIG. 2 of another embodiment. FIG. 5 is a diagram similar to FIG. 3 of a part of another embodiment. FIG. 6 and FIG. 7 are perspective views and partial cross-sectional views of another embodiment. FIG. 8 and FIG. 9 are a front view of the main part of another embodiment and a side view of a part thereof. 10 and 11 are front views of other embodiments, respectively. In FIG. 1, 10 is a vacuum vessel, 20 is an electrode, 30 is a magnetic field setting means, and 33 is a mirror magnetic field setting means.

Claims (1)

[Claims] A vacuum container and its evacuation system that evacuates the inside to a predetermined pressure, an electrode provided inside the vacuum container, means for setting a magnetic field along the surface of the electrode, and a mirror magnetic field set at the edge of the electrode. A discharge device for vacuum processing, characterized in that it is equipped with a means for.