JPS6221214A - Sputtering device - Google Patents

Abstract

PURPOSE:To prevent the variations of the state of adhesion by a method wherein a grid is provided between a target and a substrate, and the electrons flying to the substrate are absorbed by the grid, thereby suppressing the temperature rise of the substrate. CONSTITUTION:A grid 3 is arranged between a Ta target 1 and a substrate 2 located in a vacuum chamber. The grid is formed by reticulately knitting an Al wire of 500mum phi at the pitch of 5mm. After the vacuum chamber is evacuated to 10<-7>Torr, the chamber 4 is set at 1Torr or thereabout by feeding Ar gas, the Ar gas is ionized in the electric field using a power source 8, and the target 1 is sputtered by the electrons generated by said ionization to deposit on the substrate 2. At this time, the electrons having considerable kinetic energy are flown in the direction of the substrate, but as the electrons are absorbed by the grid 3, if the grid is maintained in the positive potential or equipotential with the substrate 2, the temperature rise of the substrate 2 can be suppressed, the temperature of the substrate cam be maintained at 100 deg.C or thereabout, and the variations in adhesion of the substrate can also be prevented. The density of electrons formed by ionization is made higher in the vicinity of the target 1 by magnetic poles 9 and 10, and they perform the function for improvement in the sputtering effect.

Description

[Detailed Description of the Invention] [Summary] In sputtering equipment, the distance between the target and the substrate is usually as small as about 5 cm, so electrons generated by ionization of the sputtering gas collide with the substrate, increasing the substrate temperature.
In order to eliminate the defects that change the adhesion state, a grid is provided between the mitarget and the substrate to absorb the above electrons. In this case, even if a grid is provided, the coating will not be hindered by the sputtered material getting around.

[Industrial application field]

The present invention relates to a sputtering apparatus having a structure that suppresses a rise in temperature of a substrate caused by electron collisions.

Formation of a film by sputtering uses a point source, whereas vapor deposition uses a point source, and because it uses a surface source, the sputtered material wraps around and provides better step coverage, resulting in better film uniformity. Because it is suitable for adhesion, it is often used to form wiring layers of semiconductor devices or barrier layers as underlying layers.

Aluminum (A1), tantalum (Ta), molybdenum (Mo), platinum (Pt), and the like are used as materials for sputtering.

[Conventional technology]

FIG. 2 is a schematic cross-sectional view illustrating the structure of a conventional sputtering apparatus.

In the figure, 1 is a target made of a sputtered material, and 2 is a substrate to which a film made of the sputtered material is to be deposited. - The target l and the substrate 2 are placed facing each other in the vacuum container 4, and the water-cooled cold plate 5 carries the substrate 2 and is grounded together with the vacuum container 4.

The vacuum chamber 4 contains argon (Ar) as a sputtering gas.
A gas inlet 6 for introducing gas and an exhaust lower are provided.

The robot get 1 is given a potential to the vacuum container 4 by a power source 8 .

The magnetic poles 9 and 10 are placed on the back side of the target 1 and serve to increase the density of electrons generated by ionization of the sputtering gas in the vicinity of the target 1, thereby increasing sputtering efficiency.

[Problem that the invention seeks to solve]

Conventional sputtering apparatuses have the disadvantage that electrons generated by ionization of sputtering gas collide with the substrate, increasing the substrate temperature and changing the adhesion state.

[Means for solving problems]

The solution to the above problem is to provide a mesh-like grid (3) between the target (1) and the substrate (2) on which the material constituting the target (11) is to be deposited, and to attach the grid (3) to the substrate. (2) This is achieved by the sputtering apparatus according to the present invention, which is configured to maintain a more positive potential or the same potential.

[Effect]

According to the present invention, a grid is provided between a target and a substrate to absorb electrons flying toward the substrate, thereby suppressing a rise in temperature of the substrate.

Further, even if a grid is provided, since the sputtered material comes flying from the power source, there will be no problem in film formation due to the sputtered material getting around.

〔Example〕

FIG. 1 is a schematic cross-sectional view illustrating the structure of a sputtering apparatus according to the present invention.

The figure shows a conventional apparatus shown in FIG. 2 in which a grid 3 is arranged between a target 1 and a substrate 2, and the grid 3 is electrically connected to a vacuum vessel 4.

The grid 3 is formed by winding AI wires of 500 μmφ in a mesh shape at a pitch of 5 mm.

In the figure, 1 is a target made of Ta, 2 is a target made of silicon (
5 is a cold plate made of Si), 6 is an Ar gas inlet, 7 is an exhaust port, 8 is 500V,
A 5 KW DC power supply, 9.10 is a magnetic pole that provides a magnetic field of 1 K Gauss.

Sputtering is performed as follows.

First, the target 1 and the substrate 2 are placed in the vacuum chamber 4, the exhaust is evacuated to 10-' Torr from the exhaust lower, and Ar gas is flowed through the gas inlet 6 at 10 cc/sec to bring the inside of the vacuum chamber 4 to about 1 Torr. do. Applied by power source 8,
The Ar gas is ionized by the electric field generated, and the target 1
is struck by electrons generated by ionization, sputters, and is deposited on the substrate 2.

At this time, electrons with considerable kinetic energy also fly toward the substrate 2, but are absorbed by the grid 3, so that the temperature rise of the substrate 2 is suppressed.

The temperature rise of the substrate 2 was 300 to 400°C in the conventional example, but it was reduced to about 100°C in the present invention.

〔Effect of the invention〕

As described in detail above, in the sputtering apparatus according to the present invention, since electrons flying toward the substrate are absorbed by the grid, it is possible to suppress the temperature rise of the substrate and prevent changes in the adhesion state.

[Brief explanation of drawings]

- FIG. 1 is a schematic sectional view illustrating the structure of a sputtering apparatus according to the present invention, and FIG. 2 is a schematic sectional view illustrating the structure of a sputtering apparatus according to a conventional example. In the figure, 1 is the target, 2 is the substrate, 3 is the grid, 4 is the vacuum container, 5 is the cold plate, 6 is the gas inlet, 7 is the exhaust port, 8 is the power supply, 9.10 is the magnetic pole ← Zu/V. Tsuta Threat (]f- Figure 1

Claims (1)

[Claims] A mesh-like grid (
3), and is configured to maintain the grid (3) at a more positive potential than or the same potential as the substrate (2).