JPH02246216A - Plasma device - Google Patents

Abstract

PURPOSE:To contrive wholly simplification, miniaturization, and a reduction in the production cost of a device in which the film thickness distribution is uniformized by disposing a plurality of permanent magnets and causing a piece of ring like permanent magnet among them to rotate eccentrically and making its magnetic field change continuously to allow plasma to move. CONSTITUTION:A plurality of permanent magnets 1-3 including ring like permanent magnets 2 and 3 are disposed and at least a piece of the ring like permanent magnet 2 is allowed to rotate eccentrically. Then the eccentric rotational motion of the above magnet 2 makes magnetic fields vary continuously to move plasma 6. Accordingly, plasma is beaten against targets from every possible direction and film formation materials are scattered in all directions from the targets. The device having wafers to which the film-formation materials adhere uniformly is wholly simplified, miniaturized and is manufactured at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plasma apparatus that performs sputtering and etching using plasma.

[Conventional technology]

Semiconductor integrated circuits are becoming increasingly smaller and more highly integrated, as exemplified by 1M bit dynamic RAM (random access memory).

Multilayer wiring and low-resistance wiring are progressing inside devices. Among the semiconductor manufacturing processes that make this high degree of integration possible, thin film formation technology requires higher quality.

More reliable thin film formation is required. For example, in sputtering film formation, plasma equipment that performs sputtering and etching, which are the main technologies for forming thin films, must be able to form thin films of high quality electrically, chemically, and physically.

It is required that the film has good step coverage and that the film thickness distribution and composition distribution are uniform.

In plasma sputtering equipment, to improve step coating properties and uniformity of film thickness distribution 1, uniformity of composition distribution,
It has been proposed to control plasma using magnetic fields.

A typical device of this type includes alternating large and small double plasma rings on the target surface.

A so-called double magnetic pole plasma transfer type sputtering electrode (Japanese Patent No. 12490) that can generate sputtering under independent conditions
No. 13, U.S. Pat. No. 4,401,539). The deposition distribution of the film on the wafer due to the smaller plasma ring is convex in the center, and the distribution is higher on the outside with the larger plasma ring.From these distribution states, the residence time of each plasma on the target is optimized. By repeating the movement of large and small plasma rings, a uniform film is formed over the entire surface of the wafer.

[Problem to be solved by the invention]

In the above-mentioned method of controlling plasma using conventional electromagnets, various plasma rings can be controlled by controlling the coil current of the electromagnet, but on the other hand, a power supply device and a control device are required to drive the electromagnet. There was a problem in that the number of facilities increased, making the entire device complex, large, and expensive.

On the other hand, an example of using a permanent magnet is described in "Nikkei Microdevice J, July 1988 issue, page 135," published by Nikkei BP, but other than using a permanent magnet, the method of applying the magnetic field is not disclosed. It is stated that it is not.

An object of the present invention is to provide an inexpensive plasma device in which incidental equipment can be simplified and the entire device can be simplified and downsized.

[Means to solve the problem]

In order to achieve the above object, the plasma device of the present invention includes a plurality of permanent magnets including ring-shaped permanent magnets, and at least one of the ring-shaped permanent magnets rotates eccentrically. The plasma is moved by continuously changing the magnetic field by eccentric rotation of the ring-shaped permanent magnet.

The material, dimensions, shape, and arrangement of the permanent magnets can take various forms6.For example, a small disc-shaped permanent magnet is arranged in the center, a ring-shaped permanent magnet is arranged outside it, and a ring-shaped permanent magnet is arranged outside it. A configuration is adopted in which ring-shaped permanent magnets are arranged and one or more of these permanent magnets are eccentrically rotated. By performing simulations, we can determine the material, dimensions, and shape of the permanent magnet that are most suitable for the type of target material.

Select placement and configuration and optimize.

[Effect]

In the plasma device of the present invention, a permanent magnet is used instead of an electromagnet to generate a magnetic field and control plasma, so the incidental equipment can be simplified, and the entire device can be simplified.
A plasma device that can be miniaturized and therefore inexpensive can be provided.

Furthermore, in the plasma device of the present invention, by eccentrically rotating the ring-shaped permanent magnet, the magnetic field (or magnetic flux density) generated by the permanent magnet can be continuously changed.

Therefore, in a plasma sputtering apparatus, the magnetic field changes continuously so that the plasma is swung by the changes in the magnetic field, the plasma hits the target from all directions, and the film-forming material is ejected from the target in all directions. Therefore, the film forming material can be uniformly deposited on the wafer.

It is possible to improve step filmability, uniformity of film thickness distribution, and uniformity of composition distribution. Furthermore, since the area of the target that is hit by the plasma can be expanded, the use efficiency of the target can be improved and the life of the target can be extended. Furthermore, since the film forming material can be sputtered over a wide area, a film can be formed on a large diameter wafer.

In addition, in a plasma etching apparatus, the magnetic field changes continuously, so that the plasma is swayed by the changes in the magnetic field, and the plasma hits the wafer to be etched from all directions.

The film to be etched on the wafer can be etched uniformly. Furthermore, since plasma can be applied over a wide area, wafers with large diameters can be etched.

Furthermore, in the plasma apparatus of the present invention, a plurality of permanent magnets including a ring-shaped permanent magnet are arranged, and at least one ring-shaped permanent magnet is rotated eccentrically, so that changes in the magnetic field are uniform over a wide area. The above effects can be further improved.

〔Example〕

FIG. 2 is a schematic overall configuration diagram of a plasma sputtering apparatus to which the present invention is applied.

This device has a main vacuum chamber 9 consisting of a pentagonal prism-shaped outer cylinder 7 and a cylindrical inner cylinder 8, and individual vacuum chambers are arranged on each side of the outer cylinder 7.

A rotating drum 1o is built into the main vacuum chamber 9, and a wafer holder (substrate holder with a heating mechanism during debossing) 11 is attached to this. On five sides of the main vacuum chamber 9 are four wafer processing chambers, namely processing chambers (bake stations) 12. Processing chamber ■ (sputter station) 13
, processing chamber ■ (sputter station) 14. Processing room (
A preliminary station) 15 and one pretreatment chamber 16 are provided.

The wafer holders 11 have a structure that can move in the radial direction of the rotating drum 10, and five wafer holders 11 are provided on the rotating drum 10 at equal angles.

The wafer holder 11 is moved toward the processing chambers 12 to 15 during wafer processing by a holder forward and backward drive device, and is brought into close contact with the rotating drum 1o during rotation. The wafers are transported to the pre-processing chamber 16 via the vacuum preliminary chamber 18 in load cassettes 17 or 61 wafers at a time.

A wafer heating station and a sputter etching station can be installed in the preprocessing chamber 16, and wafers can be transported and subjected to preprocessing such as baking to remove adsorbed gas or sputter etch cleaning, depending on process requirements. After being changed from horizontal to vertical by the arm, the wafer is mounted on the wafer holder 11, the rotating drum 1o rotates 115 times, and is transported to the processing chamber 112.

A predetermined process is sequentially performed in each processing chamber stationary and facing each other, and the sample is again stored in the unload cassette 20 in the atmosphere via the preprocessing chamber 16 and the vacuum preparatory chamber 19. Note that 21 is a sputter electrode.

FIG. 1(a) is a plan view showing the configuration of a permanent magnet of the plasma device of the present invention, and FIG. 1(b) is a B--B in FIG. 1(a).
The sectional view taken along section line B, Figure 1 (Q), is the same as Figure 1 (a
) is a sectional view taken along the c-c9 JTFT line.

1 is a disk-shaped permanent magnet, 2 is a ring-shaped permanent magnet placed outside the permanent magnet 1, and 3 is a ring-shaped permanent magnet placed outside the permanent magnet 2 and has a larger diameter than the permanent magnet 2. , 4 is a magnetic field line, 5 is a target (in the case of a plasma sputtering device) or a wafer (in the case of a plasma etching device), and 6 is a plasma.

In this embodiment, permanent magnets 1 and 3 are fixed, and only permanent magnet 2 rotates eccentrically. Therefore, depending on the position of the eccentrically rotating ring-shaped permanent magnet 2,
As shown in (b) and (C), since the distance between permanent magnets 1 and 2 and the distance between permanent magnets 2 and 3 change continuously, the distance between the lines of magnetic force 4, that is, the magnetic field (magnetic flux density), increases over a wide range. Change uniformly. The plasma 6 is proportional to the magnetic flux density generated on the target or wafer 5.

Therefore, in plasma sputtering equipment, plasma 6
is swung by changes in the magnetic field, the plasma 6 hits the target 5 from all directions, and the film-forming material is blown off from the target 5 in all directions. Therefore, the film-forming material can be uniformly deposited on a separately prepared wafer (not shown here), and the step coating properties, uniformity of film thickness distribution, and uniformity of composition distribution can be improved. Furthermore, since the area of the target 5 that is hit by the plasma 6 can be expanded, the usage efficiency of the target 5 can be improved.
The life of the target 5 can be improved. Also,
Since the film forming material can be sputtered over a wide area, the film can be formed on a wafer with a large diameter.

Furthermore, in the plasma etching apparatus, the plasma 6 is swayed by changes in magnetic flux density, and the plasma 6 hits the wafer 5 to be etched from all directions.
The film to be etched on the wafer 5 can be etched uniformly. Furthermore, since the plasma 6 can be applied to a wide area, a wafer 5 with a large diameter can be etched. Note that a protective film is provided in areas of the wafer 5 that should not be etched, and selective etching is performed.

In addition, in the plasma apparatus of this embodiment, a plurality of disk-shaped and ring-shaped permanent magnets 1, 2.3 are arranged, and the ring-shaped permanent magnet 2 rotates eccentrically, so that changes in the 6B field are prevented. It changes uniformly over a wide area, and the above effects can be further improved.

Furthermore, since the configuration uses permanent magnets 1.2.3 instead of electromagnets to generate a magnetic field and control the plasma 6, the incidental equipment can be simplified, and the entire plasma device can be simplified and miniaturized. The price can be reduced.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various changes can be made without departing from the spirit of the invention.

For example, the number, shape, arrangement, configuration, etc. of the permanent magnets can be modified in various ways depending on the material of the target, etc., in addition to the above embodiments.

(Effects of the Invention) As explained above, in the plasma apparatus of the present invention, the incidental equipment can be simplified, and the entire apparatus can be simplified.

A plasma device that can be miniaturized and therefore inexpensive can be provided. Further, the film forming material is uniformly adhered to the wafer, and the step coverage, uniformity of film thickness distribution, and uniformity of composition distribution can be improved.

Furthermore, the usage efficiency of the target can be improved and the life span can be extended. Furthermore, in etching, the film to be etched on the wafer can be etched uniformly. Additionally, large diameter wafers can be sputtered or etched.

[Brief explanation of drawings]

FIG. 1(a) is a plan view showing the configuration of a permanent magnet of a plasma device of the present invention, and FIG.
The sectional view taken along section line B, FIG. 1(c), is similar to FIG. 1(a).
FIG. 2 is a cross-sectional view taken along the line CC of FIG. 1... Disk-shaped permanent magnet 2. 3... Ring-shaped permanent magnet 4... Lines of magnetic force 5... Target or wafer 6... Plasma Figure 1 Figure 2 (C) (b) 1-----F1 version A Mizukatsuchi stone 5-1--Taj,, Toyota (yo wafer 2.3----Ringe) Large ゛ha permanent Hazachi stone 6-----Plus 74---.6 journey 77M

Claims (1)

[Claims] 1. A plurality of permanent magnets including a ring-shaped permanent magnet are arranged, and at least one of the ring-shaped permanent magnets rotates eccentrically, and the eccentric rotation of the ring-shaped permanent magnet creates a magnetic field. A plasma device that moves plasma by changing continuously.