JPH07226398A - Target sputtering method and target cleaning method - Google Patents

Abstract

PURPOSE:To clean the target by sputtering so as to be eroded uniformly. CONSTITUTION:A magnet rotary disc 3 on which at least one field generating magnet 2 is provided on the rear side of the target 1 of a sputtering apparatus. The center shaft 4 of the magnet rotary disc 3 is swung or revolved continuously with the center 5 of the target 1 as the center of the swing or the revolution. Or, in order to make the erosion region 10 of the target 1 which is eroded by sputtering uniform over the whole surface of the target 1, a plurality of magnet rotary discs 3 whose erosion characteristics cancel each other are employed to sputter the target 1 and the whole surface of the target 1 is cleaned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sputtering a target of a sputtering apparatus and a method for cleaning the target accompanying it.

In recent years, sputtering devices have been used for various film formations and etchings in semiconductor process steps.
The generation of particles such as dust resulting from the target during sputtering becomes a major problem with the miniaturization of semiconductor devices, and there is an urgent need to improve the sputtering method and device for reducing particles.

[0003]

2. Description of the Related Art FIGS. 4 to 5 are explanatory views of a conventional example, showing a conventional magnet rotating plate and an erosion characteristic of a target when the magnet rotating plate is used.

In the figure, 1 is a target, 2 is a magnet, 3 is a magnet rotating plate, 4 is a central axis, and 10 is an erosion region. Conventionally, the generation of particles due to sputtering has a great influence on the yield of products, and thus it is a serious problem depending on the type of target.

Particularly, in the sputtering of titanium nitride (TiN), the sputtering is performed by rotating a magnet that applies a magnetic field near the target. For example, in FIG.
Even if a single large magnet as shown in Fig. 4 is mounted on the magnet rotating plate and rotated on the back surface of the target, the erosion of the target surface is as shown in Fig. 4B, and the erosion is the entire surface of the target. It is not uniform, and as shown in the figure, there is a deeply hollowed part at a position away from the center of the target.

Therefore, as shown in FIG. 5 (a), when a magnet is changed in shape and a plurality of small targets are arranged eccentrically from the center axis of the target rotating plate in a heart shape, As shown in FIG. 4 (b), the erosion of the target is improved over the previous target so that it occurs uniformly over the entire surface of the target, and TiN
The particles from the target due to the re-precipitation have been suppressed.

Further, during the wafer processing, the inflow of nitrogen is stopped in the chamber where TiN is sputtered, and only Ti is sputtered with argon, thereby cleaning the target and suppressing the generation of particles.

[0008]

However, in the method of averaging the targets all over the surface and erosion, the amount of erosion in the target is actually shown in FIG.
As shown in (b), it is difficult to obtain a uniform film, and the TiN film is inevitably reprecipitated in a portion where erosion is small.

In order to prevent this, even if the Ti target is directly hit with only argon ions and Ti on the surface is sputtered to clean the target by erosion, sputtering with a magnet having the same shape as when forming TiN is carried out. In order to do so, it took a considerable amount of time to scrape off the re-precipitated portion, and yet it could not be completely removed.

This erosion characteristic causes this portion to be piled up while the TiN sputtering process is repeated, and further accelerates the increase of particles in the latter half of the target use period.

The present invention proposes a method for cleaning the target by sputtering so that the target is uniformly eroded.

[0012]

FIG. 1 is a diagram for explaining the principle of the present invention. In the figure, 1 is a target, 2 is a magnet, 3 is a magnet rotating plate, 4 is a central axis, 5 is a center, and 6
Is a substrate, 7 is an incident ion, 8 is a sputter atom, 9 is a target holder, and 10 is an erosion region.

As a means for solving the above problems, first, as shown in FIG. 1A, the rotation center axis 4 of the magnet rotating plate 3 on the back surface of the sputtered target 1 is perpendicular to the center axis. Continuous oscillating and shifting in the horizontal direction or rotational movement of the central axis 4 around the center 5 of the target 1 prevents local erosion of the target 1 and, as shown in FIG. Make sure that uniform erosion occurs on the entire surface of 1.

Second, in order to clean the target 1, only argon (Ar) is introduced as a gas for sputtering, Ar ions as incident ions 7 are bombarded on the target 1 of Ti, and Ti is used as sputtered atoms 8. The surface of the target 1 is eroded by tapping to clean the surface.

In this case, when only Ti is sputtered, the specific magnet rotary plate 3 attached to the back surface of the target has the erosion characteristics as shown in FIG. Since the part to be removed is determined near the center, the part is intensively cut, and the Ti target 1 is cleaned by replacing the part with a magnet rotating plate 3 having erosion characteristics as shown in FIG. 1C, for example. Then, the erosion characteristic of the target 1 as shown in FIG. 1D is obtained.

That is, an object of the present invention is to provide a magnet rotating plate 3 provided with at least one magnetic field generating magnet 2 provided on the back surface of a target 1 of a sputtering apparatus.
At least one magnetic field generated by rotating the central axis 4 of the target 1 with respect to the center 5 of the target 1 by constantly swinging or swirling the periphery thereof or provided on the back surface of the target 1 of the sputtering apparatus. The target 1 is sputtered by using a plurality of magnet rotary plates 3 that cancel the erosion characteristics of the target 1 when the target 1 is sputtered by rotating the magnet rotary plate 3 with the mounting magnets 2 attached. However, this is achieved by making the erosion uniform when cleaning the entire surface of the target 1.

[0017]

As described above, according to the present invention, the central axis of the magnet rotating plate for generating a magnetic field on the back surface of the target is swayed in the front-rear direction, or a plurality of magnet rotating plates are used to correct the erosion characteristics for cleaning. Or
Uniformize the erosion characteristics of the target. This method reduces particles during sputtering and improves the yield.

In addition, the period in which the target is used is extended as compared with the conventional case, and the life of the target is extended.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 2 to 3 are explanatory views of first and second embodiments of the present invention. In the figure, 1 is a target, 2 is a magnet, 3 is a magnet rotating plate, 4 is a central axis, and 10 is an erosion region.

A first embodiment of the present invention will be described with reference to FIG. A TiN film is formed using a film forming sputtering apparatus. Ar target in the chamber using Ti target 1
Sccm, nitrogen (N ₂ ) 40sccm is flown, substrate temperature 300 ℃,
When the sputter output was 6.0 KW and the sputter time was 35 seconds, the amount of dust increased from the 20th continuous processing of the semiconductor substrates 6 to the considerably large number at the 100th processing.

Therefore, the target 1 of Ti is sputtered by flowing only Ar and the surface of the target is cleaned by sputtering. The condition is Ar 1
Flowing at 00 sccm, the substrate temperature is 300 ° C., the sputter output is 5 kW, and the sputter time is 30 seconds.

At this time, conventionally, the magnet rotary plate 3 on the back surface of the target 1 was only rotated, but in the present invention, as shown in FIG. Move the central axis of No. 3 vertically and horizontally to the axis and rotate eccentrically while swinging continuously, or scroll the central axis 4 to make a planetary motion as shown in FIG. 2 (c). As a result, the shaving amount of the target is made uniform as shown in FIGS. 2B and 2D, and the erosion region as shown in the figure is obtained.

Therefore, even in the latter half of the usage period of the target, the amount of dust remained almost unchanged. A second embodiment of the present invention will be described with reference to FIG.

First, the sputtering conditions for the TiN film are the same as in the first embodiment. However, in the next cleaning, the magnet rotating plate 3 having the arrangement of the magnets 2 as shown in FIG. 3A is used, and the erosion characteristics as shown in FIG. 3B, that is, the center of the target is more eroded. Using magnet rotating plate 3
The erosion characteristics with little erosion in the center of the target shown in FIG. 5A used during the iN film sputtering are offset.

The sputtering conditions for cleaning the Ti target in this case are the same as in the first embodiment. Also in this case, the amount of shaving is made uniform as in the first embodiment,
The erosion region as shown in FIG.

[0026]

As described above, according to the present invention,
Since the erosion area of the target is made uniform over the entire surface of the target, particles such as dust generated from the target are significantly reduced, the period of use of the target itself is extended, and the characteristics and reliability of the semiconductor element are improved, and It greatly contributes to cost reduction.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 is an explanatory diagram of the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a conventional example (No. 1)

FIG. 5 is an explanatory diagram of a conventional example (No. 2)

[Explanation of symbols]

 1 Target 2 Magnet 3 Magnet Rotating Plate 4 Center Axis 5 Center 6 Substrate 7 Incident Ion 8 Sputtering Atom 9 Target Holder 10 Erosion Area

Claims (2)

[Claims] 1. At least one magnetic field generating magnet provided on the back surface of a target (1) of a sputtering apparatus.
Install the center axis (4) of the magnet rotating plate (3) with (2)
With respect to the center (5) of the target (1), the periphery of the target (1) is continuously swung or swung to rotate the target (1).
A sputtering method for a target, which comprises sputtering (1). 2. At least one magnetic field generating magnet provided on the back surface of the target (1) of the sputtering apparatus.
When the magnet rotating plate (3) equipped with (2) is rotated to perform sputtering of the target (1), the erosion area (10) due to sputtering of the target (1) is the target (1). The target (1) is sputtered by using a plurality of magnet rotating plates (3) whose erosion characteristics are canceled so that the target (1) is uniformly cleaned over the entire surface of the target (1). Characteristic target cleaning method.