JPH0280564A - Sputtering device - Google Patents

Abstract

PURPOSE:To reduce the dispersion of the change in film-thickness distribution on a substrate with the lapse of time by providing a shielding mask in which the size of an opening part can be freely changed between a target and a substrate to be treated in a planar magnetron sputtering device. CONSTITUTION:In a planar magnetron sputtering device having a magnetic field-impressing mechanism, such as magnet, on the rear of a target, an upper shielding plate 1, a lower shielding plate 2, a side shielding plate (right) 3, and a side shielding plate (left) 4 are disposed between a target and a substrate to be subjected to thin film formation, and these plates are set so that they are movable vertically and horizontally on rails 5 by means of drive motors 6. By the movement of the above four shielding plates 1-4, the size of a shield opening part can be arbitrarily controlled and only the circular or eliptical part in the central part can be locally sputtered, by which the distribution of the thickness of a thin film to be formed can be prevented from increasing with the lapse of time and the quality and the yield of the substrate on which the film is formed can be remarkably improved within the period of the service life of the target.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sputtering apparatus, and more particularly to the structure of a shield mask for forming a film on a substrate using a sputtering apparatus having a planar magnetron cathode.

[Conventional technology]

Traditionally, some of the techniques for forming thin films by sputtering include:
There is a planar magnetron sputtering method that is fast and causes little rise in substrate temperature. The planar magnetron method is a method in which a magnetic field application mechanism is provided behind the target to locally increase the plasma density on the target surface to perform sputtering efficiently. However, although this method has a high sputtering speed and efficiency, sputtering is performed only in local circular or elliptical areas, which tends to cause film thickness distribution on the substrate depending on the positional relationship between the target and the substrate. In order to improve this problem, a shield mask is inserted between the target and the substrate as described in JP-A-60-19786, and JP-A-60-19786 As described in Japanese Patent No. 19407, a shield mask shape that makes the film thickness uniform is specified. In addition, the film formation rate can be changed by changing the two-row region as described in JP-A-60-202543, or by changing the target shape as described in JP-A-60-200962. Let,-
We have been applying various types of membranes.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, with the method of selecting a shield mask and a constant shape of the target, the film thickness distribution caused by changes over time, that is, erosion over time within the life span of the target, cannot follow changes in the film formation rate. No consideration was given to the fact that the membrane would become difficult.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a sputtering apparatus having a shield mask structure that eliminates the above-mentioned problems and is possible within a target life span.

[Means to solve the problem]

In order to achieve the above object, a shape-variable shield mask is used in the sputtering apparatus of the present invention. In other words,
The shield mask consists of four points: top, bottom, left, and right.
By arbitrarily controlling the size of the opening using four drive systems, fluctuations in film formation rate and film thickness distribution within the target life can be eliminated.

[Function] The variable-shape mask is basically shaped like a normal regular shield mask, and at the initial stage of film formation, has a mask shape that makes the film thickness distribution uniform, for example.

This is because the film is thick at the center of the target and thin at the outer periphery, so the outer area is larger. In this case, the mask has an optimal shape to make the thin film uniform. Due to the shape of the film, when the target changes over time and the second region progresses, the film formation rate at the outer periphery decreases. In this case, the mask shape is made such that its outer peripheral region is widened, and the relative speed of film formation is changed so as not to change over time. Thereby, the uniformity of the film thickness and the film formation rate are maintained at an optimum state.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an example of a configuration diagram of a shield mask of the present invention. As shown in FIG. 1, the shield mask consists of an upper shield plate 1. It is composed of a lower shield plate 2, a horizontal shield plate (right) 3, and a horizontal shield plate (left) 4. The shape of the shield mask opening formed by the upper and lower, left and right shield plates is determined by a straight line, a curved line, or a straight line and a curved line. This example is a shield mask having an opening shape of a linear configuration.

The upper and lower shield plates move vertically, and the left and right shield plates move laterally. Additionally, the shield plate has a partially shuttered structure to ensure a storage area for the movable parts. In addition, each shield plate has a guide rail 3, which guides the shield plate to move smoothly and linearly. Also, each shield plate shutter winding portion is combined with a drive motor, and each shield plate can be operated independently. It is connected to a controller outside the chamber for movement. The controller is capable of positioning the shield plate.

The shield mask is located between the target and the substrate, as shown in FIG.

In the initial state of film formation, the mask shape is determined so that the film thickness is within ±2% of the set value. Thereafter, by moving the shield plate using the controller so as not to deviate from the film thickness of ±2% depending on the target usage conditions, it is possible to produce good products up to the target usage limit.

The basic shield mask opening shape and the number of shield mask constituent plates are optimized according to the sputtering equipment and the target material used to achieve uniform film thickness. Figure 3 shows examples of various shield mask opening shapes and the number of constituent plates. shows. Although the number of shield plates is arbitrary, examples will be shown in which the shield plates are made up of four plates and the shield plates are made up of six plates. The shape of the shield mask entrance varies depending on the target shape, but when the target shape is rectangular, the shield mask opening shape should preferably have a large sputtering area on the outer periphery.

Further, due to the positional relationship between the two lotion areas of the target and the shield mask, the shape of the shield plate in the vertical and horizontal directions is also asymmetrical.

By using this device, effective results can be obtained in making the film thickness uniform for target magnets such as S, -C0, etc. used for ferromagnetic targets and general permanent magnets used for non-magnetic targets.

Further, both RF and DC can be used as the sputtering power source.

In the examples shown below, a shield mask having the opening shape shown in FIG. 1 was used to form a film on a rectangular target material. The sputtering conditions are: using a DCN source, chamber vacuum pressure I x 10' Torr or less, and Ar gas pressure I Q m T for the metal target.
orr, Ar gas pressure 1.5mT for carbon target
Films were formed on various targets at the power input shown in the table.

The film thickness distribution was expressed as a percentage of variation with respect to the average film thickness.

For comparison, evaluation was conducted under the same conditions using a conventional fixed aperture shield mask, and the results are shown in Table 1 as a comparative example.

From Table 1, it is possible to obtain a stable film thickness distribution according to the present invention, which is approximately 2% immediately after the start of use of the target and 2 to 3% immediately before the end of the target life.

〔Effect of the invention〕

According to the present invention, the film thickness distribution can be reduced from the conventional variation of ±10% due to aging to about 2% or less, which has the effect of significantly improving performance and yield.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a shape variable shield mask for sputtering according to an embodiment of the present invention, Fig. 2 is a configuration diagram of the shield mask, and Fig. 3 shows various opening shapes of the shield mask and four shield plates. FIG. 4 is an explanatory diagram of an example of a shield mask composed of six sheets. 1... Upper shield plate, 2... Lower shield plate. 3...Horizontal shield plate (right). 4...Horizontal shield plate (left), 5...Guide rail, 6...Drive motor, 7...Controller. Figure 1

Claims (1)

[Claims] (1) In a sputtering device consisting of an evacuation system, a vacuum chamber, a sputtering cathode, a shield mask, a sputtering power source, an inert gas supply device, and a substrate,
The shield mask is composed of two or more items, each of which has a mechanism and drive system that moves horizontally or vertically, and has a mechanism that can control the film thickness distribution on the substrate in vacuum. Characteristic sputtering equipment.