JPH02236277A - Sputtering method - Google Patents

Abstract

PURPOSE:To prevent the reaction product sticking to the nonerosion region of a target used in magnetron sputtering from peeling and the surface of a substrate subjected to a sputtering treatment from being thereby contaminated by roughening the surface of the non-erosion region or coating the surface with the reaction product with the target material. CONSTITUTION:The annular region 2 of the circular target 1 is released in the form of atoms by the bombardment of Ar ions and the atoms react with gaseous N2 to form the thin film of TiN on the substrate to be treated at the time of using Ti as the target 1 by the magnetron sputtering using the gaseous Ar contg. N2 and forming the thin film of the TiN on the substrate by reactive sputtering. The surface of the non-erosion area 6 by the Ar ions is roughened by mechanical polishing or the TiN 8 of the reaction product is previously adhered to the surface, by which the peeling of the TiN sticking to the non-erosion region 6 during the operation and the adhesion and contamination thereof as the dusty TiN on the vapor deposited TiN film on the substrate surface are prevented even ig the TiN exclusive of the TiN deposited by evaporation on the substrate sticks to the non-erosion region.

Description

[Detailed Description of the Invention] [Summary] Concerning a sputtering method using a magnetron sputtering method. In order to prevent the reaction products deposited on the surface of the target other than the eroded portion from peeling off, the surface facing the counter electrode other than the eroded portion is roughened or the surface that is not introduced into the sputtering equipment is roughened. The target is coated with the same substance as the reaction product of the raw material gas and the target constituent material.

[Industrial application field]

The present invention relates to a magnetron sputtering method, and in particular to an improvement of its target. [Conventional technology] Magnetron sputtering has high plasma generation efficiency. It has the characteristic of obtaining a high sputtering rate. however. The distribution of ion density incident on the target surface is not necessarily uniform. the result. Sputtering is large in a specific area of the target surface. For example, as shown in the cross-sectional view of FIG. 3(a), the sputtering rate is high in the annular region 2 on the surface of the circular target 1, and the sputtering rate is low in the central portion 3 and peripheral portion 4. For this reason, a phenomenon occurs in which a part of the target material sputtered in the region 2 is deposited in the central part 3 and the peripheral part 4.

Therefore, since only the annular region 2 appears to be sputtered and consumed, such a nodding region 2 is called an erosion region.

[Problem to be solved by the invention]

When forming a desired thin film by directly depositing the target material on the surface of the substrate to be processed. Even if the above-mentioned material transfer from the erosion region to the non-erosion region occurs, no particular problem occurs. This is because the non-erosion area and the substance deposited there are the same and have good adhesion to each other.

However, for example, if nitrogen (N2) is added to argon (^r) gas,
Titanium nitride (
Deposit a TiN) thin film. In the case of so-called reactive sputtering. Materials deposited in non-erosion areas are likely to peel off.

As shown in the cross-sectional view of FIG. 3(b), for example, when forming a TiN film, the TiN film 7 is deposited on the surface of the Tf target 5 in the non-erodible region 6, but when the film thickness increases to a certain extent, the target It peels off relatively easily from the surface. It adheres to the surface of the substrate to be processed (not shown).

This peeling film is a type of dust and causes various defects in semiconductor devices manufactured using the substrate to be processed. Also. If a conductive peeling film such as TiN causes a short circuit between the target and the shielding electrode that is provided very close to the target to prevent unnecessary discharge within the sputtering equipment. Due to the abnormal current flowing, a problem arises in which stable sputtering cannot be performed.

The non-uniform incident ion density, which is the root cause of the above problem, is due to the distribution of the magnetic field applied to the plasma, and sputtering is an improved method of applying a magnetic field to make the incident ion density uniform. Equipment is also provided. however. Since it is extremely difficult to make such improvements to existing equipment, there has been a desire to prevent the reaction product film deposited in the non-bilosion region from peeling off.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a target for a reactive sputtering apparatus that is treated so that a product film deposited in a non-erosion region is difficult to peel off.

[Means to solve the problem]

The above object is a magnetron sputtering sputtering method in which the surface facing the counter electrode other than the erosion part is roughened or the material gas introduced into the sputtering apparatus and the target constituent material are roughened. This is achieved by the sputtering method according to the present invention, which is characterized in that it uses a target coated with the same substance as the reaction product.

[For production]

Is it possible to improve the adhesion of thin films deposited in this region by roughening the surface of the non-erosion region of a target for a magnetron sputtering system? Alternatively, the surface of this nodule area may be coated with the same material as the product produced by reactive sputtering to increase adhesive strength and prevent peeling. As a result, the problem of defects caused by the adhesion of the peeled matter in the manufacture of semiconductor devices consisting of one substrate to be processed can be solved.

〔Example〕

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

In the following drawings, the same parts as in the previously published drawings are designated by the same reference numerals.

FIG. 1 is a sectional view of essential parts showing an embodiment of the structure of the target of the present invention. Non-erosion region 6 on the surface 14 facing the counter electrode (not shown) on the surface of the target 1
The surface is roughened, for example, by mechanical polishing. This roughening occurs when the height of the unevenness measured with a surface roughness meter is 1.
Approximately 3 μm is appropriate, and even larger than 1 μm.
Even if it is small, the adhesion of the deposited film will be low.

The positions of the annular region 2, that is, the erosion gon region and the non-erosion head region 6, are unique to each sputtering device. Determine in advance through preliminary experiments.

FIG. 2 is a sectional view of a main part showing another embodiment of the structure of the target of the present invention, in which the non-erosion region 6 on the surface IA of the target 10 is formed by a product of reactive sputtering, for example, titanium in an atmosphere containing nitrogen. When TiN is deposited by sputtering, it is covered with a TiN layer 8. TiNJi8 was applied to the surface of target 1, which was made of a smooth titanium plate. A TiN film may be selectively formed, or disk-shaped and annular TiN ceramic members may be bonded to the non-erosion region 6 at the center and periphery of the target 1 surface, respectively. It may be inserted into a recess provided in the. The target 1 made of a titanium plate and TiN may be bonded using, for example, a metal bonding method.

FIG. 4 is a schematic configuration diagram of a sputtering apparatus for carrying out the present invention, in which an electrode 11 and a target 13 as shown in FIG. 1 or 2 are provided inside the processing tank 10. , for example, a substrate 1 to be processed to which TiN is deposited.
2 are placed facing each other.

While the inside of the processing tank 10 is evacuated by a pump (not shown) through the exhaust pipe 15, argon gas to which nitrogen has been added is introduced through the gas introduction pipe 16, and power is supplied to the electrode 11 by the high frequency power source RF, thereby causing the target 13 to be processed. Board 1
Plasma is generated between the two, and the target 13 is sputtered. Reference numeral 14 is a magnet for applying a magnetic field to focus the plasma.

〔Effect of the invention〕

According to the present invention, in the manufacture of semiconductor devices using the magnetron sputtering method, the surface of the substrate to be processed is contaminated by dust generated by peeling off the product thin film deposited on the non-erosion area of the sputtering target, or abnormal discharge occurs in the sputtering equipment. This has the effect of making it possible to improve the manufacturing yield of the semiconductor device.

It is.

[Brief explanation of drawings]

Figures 1 and 2 are sectional views of essential parts showing an embodiment of the present invention, Figure 3 is a diagram explaining conventional problems, and Figure 4 is a schematic configuration diagram of a sputtering apparatus for implementing the present invention. . In the figure, l indicates target 2 is an annular region (erosion region), and 3 indicates the center.
4 is a peripheral area, 5 is a Ti target 6 is a non-erosion area, 7 is a TiN film, 8 is a TiN layer, 10 is a processing tank,
11 is the electrode layer, 12 is the substrate to be processed, and 13 is the target 1.
4 is a magnet, 15 is an exhaust pipe, 16 is a gas introduction pipe.

Claims (1)

[Claims] A sputtering method using a magnetron sputtering method, in which the surface facing the counter electrode other than the erosion part is roughened, or a reaction product between the raw material gas introduced into the sputtering apparatus and the material constituting the target is formed. A sputtering method characterized by using targets coated with the same substance.