JP2648111B2 - Collimator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collimator provided above a semiconductor substrate in a sputtering process for forming a uniform metal thin film of a semiconductor device, and more particularly to a collimator provided in one collimator depending on a position. The present invention relates to a collimator in which a collimator hole is formed so that a height of a side wall and a hole diameter of the hole are different from each other, and the step coverage of a metal thin film can be improved.

[0002]

2. Description of the Related Art In general, in a sputtering process for depositing a metal thin film, argon (Ar) gas is turned into plasma, and argon ions and the like collide with a metal source (Source). Will be formed.

[0003] Since the metal atoms and the like jumping out of the source reach the substrate at various angles,
In a contact hole having a high step ratio due to high integration of a semiconductor element, step coverage of a metal thin film becomes poor.

Therefore, in a recent sputtering process, a metal net called a collimator is provided between the source and the substrate so that metal atoms or the like incident at a low angle on the substrate are deposited on the collimator, and a high angle is formed on the substrate. That is, research is being conducted to improve the step coverage by allowing only vertically incident metal atoms or the like to reach, and some of them have been put to practical use.

[0005] Currently, the collimator which has been developed and used and is under study is a metal mesh having a honeycomb-shaped regular hexagonal shape or a circular hole, and the size and height of the hole in the collimator are constant. Is formed.

A conventional collimator will now be described with reference to FIGS. 1 to 6 as follows.

First, each collimator (10),
(12), (14), (16), (18), (20)
Are holes (1) whose collimator diameter is x or y, respectively.
1), (13), (15), (17), (19), (2)
1) is a metal net or the like formed continuously at the collimator height of a, b or c.

[0008] The conventional collimator has holes (11), (13), (15), (17) and (1).
9), the step ratio a / x, b / x, c / x or a / y, b of the collimator hole, which is the ratio of the height of the collimator hole to the collimator diameter (x, y) in (21). /
y and c / y have the same value.

[0009]

As described above, since the conventional collimator has the same value of the step ratio of the collimator hole, uniform consumption of the sputtering metal source, that is, uniform erosion, is not achieved. If it does not occur, there is a problem that a more uniform metal thin film is formed even when a collimator is used than when it is not used.

In order to solve such problems, it is required to provide a novel sputtering apparatus. However, it is still very difficult to manufacture a sputtering apparatus that generates completely uniform erosion of the source.

An object of the present invention is to solve the above-mentioned problems. An object of the present invention is to use a collimator in which the diameter and height of a hole are different depending on the position in the collimator, so that the metal can be used. An object of the present invention is to provide a collimator capable of easily depositing a uniform metal thin film on a substrate without replacing a sputtering apparatus even when uniform erosion of a metal source does not occur when depositing the thin film.

[0012]

In order to achieve the above object, a collimator according to the present invention includes a sputtering method for depositing a metal thin film on a semiconductor device, in which a collimator is provided between a target (Target) as a metal source and a substrate. In the collimator placed between the target and the substrate through multiple collimator holes, a step that is the ratio of the height to the diameter of the collimator hole is formed so that a uniform metal thin film can be formed on the semiconductor element. The ratio is different between any collimator hole and other collimator holes.

[0013]

The collimator of the present invention, which has a plurality of collimator holes having different collimator step ratios within one collimator, can be modified into various forms to match the erosion form of the source. Thus, a uniform metal thin film can be obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a collimator according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 7 to 12 show collimators (22), (24), (26), (28), (3) according to the present invention.
0) and (32) are cross-sectional views showing a circular hole (23);
(25), (27), (29), (31), and (33) are examples in which they are continuously formed.

First, FIG. 7 and FIG. 8 show collimators (22) and (24) having a high step ratio at the center, and the thickness of the metal layer deposited at the center of a substrate (not shown) is reduced. It is formed thin. That is, when a large amount of metal source erosion occurs at the central portion, a uniform thin film can be obtained by using the collimator (22) or (24).

FIGS. 9 and 10 correspond to FIGS.
On the contrary, the collimator (2
6) and (28), which are collimators capable of reducing the thickness of the metal layer deposited on the edge of the substrate.

FIG. 11 shows that the diameter and height of the hole (31) of the collimator (30) are simultaneously changed to increase the step ratio for each part, when the erosion of the metal source edge side part is extremely severe. And a uniform metal thin film can be obtained.

FIG. 12 shows a collimator (32) used for the purpose opposite to that of FIG. 11 when the erosion of the central portion of the metal source is severe.

Here, x ₁ , x ₂ , x ₃ , and x ₄ indicate the diameters of the holes of the collimators having different diameters from each other.
a _1, a _2, a ₃ and _{b, b 1, b 2,} b 3 indicates the height of the different collimator holes each other.

Therefore, in the collimator according to the present invention, the step ratio, which is the ratio between the diameter of the collimator hole and the height of the hole, is formed in one collimator to be different for each desired portion.

[0022]

As described above, the collimator formed according to the present invention can eliminate the nonuniformity of the thickness of the deposited metal thin film without replacing the sputtering equipment, and can reduce the thickness of the semiconductor device. There is an advantage that reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a conventional collimator and the like.

FIG. 2 is a sectional view of a conventional collimator and the like.

FIG. 3 is a sectional view of a conventional collimator and the like.

FIG. 4 is a sectional view of a conventional collimator and the like.

FIG. 5 is a sectional view of a conventional collimator and the like.

FIG. 6 is a sectional view of a conventional collimator and the like.

FIG. 7 is a sectional view of a collimator and the like according to the present invention.

FIG. 8 is a sectional view of a collimator and the like according to the present invention.

FIG. 9 is a sectional view of a collimator and the like according to the present invention.

FIG. 10 is a sectional view of a collimator and the like according to the present invention.

FIG. 11 is a sectional view of a collimator and the like according to the present invention.

FIG. 12 is a sectional view of a collimator and the like according to the present invention.

[Explanation of symbols]

10, 12, 14, 16, 18, 20, 22, 24, 2
6, 28, 30, 32 ... collimator, 11, 13, 1
5,17,19,21,23,25,27,29,3
1,33 ... Hall.

Claims (3)

(57) [Claims] 1. A collimator which is placed between a target of a metal source and a substrate in a sputtering step of depositing a metal thin film on a semiconductor element, and which communicates between the target and the substrate through a plurality of collimator holes. So that a uniform metal thin film can be formed on the semiconductor element,
A collimator characterized in that a step ratio, which is a ratio of a height to a diameter of the collimator hole, is different between an arbitrary collimator hole and another collimator hole. 2. The collimator according to claim 1, wherein the plurality of collimator holes have the same height. 3. The collimator according to claim 1, wherein a diameter and a height of an arbitrary collimator hole of the plurality of collimator holes are different from other collimator holes.