JPH01309966A - Sputtering device - Google Patents

Abstract

PURPOSE:To prevent the abnormal rise of substrate temp. at the time of increasing sputter electric power by providing an auxiliary magnetic means having specific properties to the rear of a substrate to be treated and also interposing an intermediate electrode between a target and the substrate to be treated in a magnetron sputtering device. CONSTITUTION:An auxiliary electrode 11 is provided to the rear of a holder 9 for a substrate 10 in a vacuum tank 8 in a magnetron sputtering device, and flowing of electrons moving along leakage magnetic force lines 12 from the surface of a target 4 into the substrate is prevented by the magnetic field formed by the lines 13 of magnetic force from the above electrode 11. Further, by impressing a positive voltage of <=100V by means of an electric power source 15 on an intermediate electrode 14 provided between the substrate 10 and the target 4 or carrying out grounding, high-speed electrons are captured by the intermediate electrode 14 and the flowing of the high-speed electrons into the substrate 10 is reduced, by which the abnormal temp. rise in the substrate 10 and the resulting deformation of the substrate 10 can be prevented even if sputter electric power is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a sputtering apparatus for forming a thin film on a substrate by sputtering in semiconductor processing technology, surface treatment technology, etc.

Conventional technology Currently, thin film formation by magnetron sputtering is widely used in the T industry, but when high power is applied to the cathode to increase the film formation rate, the substrate temperature rises due to electron inflow from plasma, etc. Therefore, substrate cooling is performed.

A conventional sputtering apparatus will be described below with reference to the drawings. FIG. 4 shows the configuration of a conventional sputtering apparatus. 17 is a cathode body for fixing a magnet 18° yoke 19, 520 is a target, 21 is a plasma shield, 22 is a cooling water inlet for cooling the target 20, and 23 is a cooling water inlet/outlet. Reference numeral 24 denotes a chamber that supports the cathode body 1 and the substrate holder 26 and whose interior can be evacuated. 26 is a board holder 25
This is a substrate cooling device for cooling S. Further, 27 is a substrate on which a film is formed by sputtering, and is mounted on a substrate holder 26.

The operation will be explained below. The inside of the chamber 24 is evacuated to a pressure on the order of 10 Torr using a vacuum pump.

Thereafter, argon gas is introduced and the pressure is controlled to about 5×10 Torr, and a direct current or high frequency voltage is applied to the cathode body 17 by the power source 28. This generates plasma within the chamber 24, thereby generating argon ions. Further, a region with high plasma density is generated by the magnetic field 29 of the magnet 18, thereby increasing the amount of argon ions colliding with the target 20, and forming a film on the substrate 1γ. On the other hand, due to the leakage magnetic field 30 from the target surface, electrons flow from the plasma into the substrate 27.
Although the temperature of the substrate 2 rises, the temperature of the substrate 2 increases due to the substrate cooling device 26.
7 is cooled and prevents the temperature from rising.

Problems to be Solved by the Invention However, with the above configuration, if a material with low thermal conductivity such as plastic or glass is used for the substrate 27, the substrate cooling device 26 will not operate effectively and the substrate temperature will rise. As a result, there is a problem that the sputtering power that can be applied is limited and the film formation rate is slow. FIG. 5 shows the relationship between sputtering power, substrate temperature, and film formation rate. The horizontal axis is sputtering power, and the vertical axis is substrate temperature and film formation rate. Even when the substrate cooling device 2θ was operated, when a power of 2 KW or more was applied, the substrate temperature rose to 100° C. or more, and deformation of the substrate was observed.

In view of the above problems, the present invention is designed to prevent a rise in substrate temperature when sputtering power is increased.

Means for Solving the Problems A first aspect of the present invention provides magnetic lines of force L2 perpendicular to the surface of the substrate to be processed, in a direction that cancels the leakage magnetic field from the magnetic means that forms a magnetic field on the target surface to the surface of the substrate to be processed. The present invention is characterized in that it has an auxiliary magnetic means for the substrate that forms a magnetic field.

A second aspect of the present invention is characterized in that an intermediate electrode with a positive voltage of 100 V or less or grounded is provided between the magnetic means for forming a magnetic field on the target surface and the auxiliary magnetic means for the substrate.

The first aspect of the present invention has the above-described configuration, and the electrons flowing into the substrate along the leakage magnetic field lines from the target surface to the substrate surface are redirected by the magnetic field formed by the auxiliary magnetic means for the substrate. The reflected electrons reduce the flow of electrons into the substrate, and the rise in substrate temperature is suppressed.

According to the second aspect of the present invention, with the above-described configuration, high-speed electrons from the target, which are difficult to reflect by the substrate auxiliary magnetic means, flow into the intermediate electrode, further reducing the flow of electrons into the substrate, and suppressing a rise in substrate temperature.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIG. 1 is the magnet 2, the cathode body that fixes the yoke 3, 4 is the target, 5 is the plasma shield, 6 is the target 4
7 is the cooling water inlet of the reservoir, and 7 is the cooling water outlet. Reference numeral 8 denotes a chamber that supports the cathode body 1 and the substrate holder 9 made of a magnetic material and whose interior can be evacuated. 1° is a substrate on which a film is formed by sputtering and is mounted on a substrate holder 9. Reference numeral 11 denotes an auxiliary magnet for applying a magnetic field to the surface of the substrate 10. 12° 13 are lines of magnetic force formed by the magnet 2 and the auxiliary magnet 11. 1
4 is a ring-shaped intermediate electrode provided at a position where the magnetic fields of the magnet 2 and the auxiliary magnet 11 cancel each other out. 15 is a power source for applying a positive voltage of 10 Qv or less to the intermediate electrode.

The operation will be explained below. The inside of the chamber 8 is evacuated to a pressure on the order of 10 Torr using a vacuum pump.

Thereafter, argon gas is introduced, the pressure is controlled to about 6×10 4 Toττ, and a direct current or high frequency voltage is applied to the cathode body 1 by the power source 16. As a result, plasma is generated within the chamber 8, and therefore argon ions are generated.

Furthermore, a region with high plasma density is generated by the magnetic field 17 of the magnet 2, thereby increasing the amount of sialygon ions colliding with the target 4, and a thin film is formed on the substrate 10 by sputtering of argon ions.

On the other hand, electrons move along leakage lines of magnetic force 12 from the target surface, but are reflected by the magnetic field formed by the auxiliary magnet 11 and are prevented from flowing into the substrate 10. In addition, by applying a positive voltage to the intermediate electrode 14, the magnetic field lines 12.1
3, high-speed electrons that are difficult to trap are captured by the intermediate electrode 14, and the inflow of electrons into the substrate 10 is further reduced. Figure 2 shows the correlation between reflected magnetic field strength and substrate temperature rise. The horizontal axis is the reflected magnetic field strength, and the vertical axis is the substrate temperature rise. By setting the reflected magnetic field to 20 Gauss or more, the rise in substrate temperature is reduced, and high-speed film formation by high-power sputtering becomes possible even on the substrate 10 made of a material with low thermal conductivity such as plastic. Still the third
The figure shows the difference in substrate temperature rise depending on the presence or absence of an intermediate electrode. The installation of an intermediate electrode suppresses the rise in substrate temperature and enables high-speed film formation using a large scale batter.

In this embodiment, the substrate auxiliary magnet 11 is a permanent magnet, but it may also be an electromagnet.

Furthermore, in this embodiment, the intermediate electrode 14 is ring-shaped; however,
The shape may be changed to a menyu shape or the like.

Effects of the Invention As described above, the first aspect of the present invention is a magnetic means having lines of magnetic force perpendicular to the surface of the substrate to be processed, and a magnetic means that forms a magnetic field on the target surface in a direction that cancels the leakage magnetic field on the surface of the substrate to be processed. By providing an auxiliary magnetic means for the substrate that forms a magnetic field on the substrate, electrons flowing into the substrate along the leakage magnetic field lines from the target surface to the substrate surface are reflected by the magnetic field formed by the auxiliary magnetic means for the substrate. It is possible to reduce the inflow of electrons into the substrate and suppress the rise in substrate temperature.

The second aspect of the present invention is to provide a positive voltage of 100 V or less or a grounded intermediate electrode between the magnetic means for forming a magnetic field on the target surface and the auxiliary magnetic means for the substrate.
The substrate auxiliary magnetic means captures high-speed electrons from a target that is difficult to reflect, further reduces the inflow of electrons into the substrate, and suppresses a rise in substrate temperature.

[Brief Description of the Drawings] Figure 1 is a configuration diagram of a sputtering apparatus according to an embodiment of the present invention, Figure 2 is a diagram showing the relationship between reflected magnetic field strength and substrate temperature rise, and Figure 3 is a diagram showing the relationship between the intensity of the reflected magnetic field and the rise in substrate temperature. FIG. 4 is a diagram showing the difference in substrate temperature rise, FIG. 4 is a configuration diagram of a conventional sputtering apparatus, and FIG. 5 is a diagram showing the relationship between sputtering power, substrate temperature, and film formation rate. 1...Cathode body, 2...Magnet, 3
...Yoke, 4...Target, 8.
...Chamber, 9...Substrate holder, 1
o...Substrate, 11...Auxiliary magnet, 14
・・・・・・Intermediate electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
Cathode body 2...-Magnet 4- Target a-4-y buckwheat? -... Board holder IQ-11 board 11... - Auxiliary 1 oak! 4.-Middle t! & Figure 1 Atsushi 2 Figure OTo Ka3D40 Reflected magnetic field heel cliff (7i Hus) Figure 3 Nakayami Den Yu Ha Figure 4 A

Claims (3)

[Claims] (1) A target as a film forming source made of a material to be sputtered in a vacuum container, and a cathode on which this target is placed;
A power supply that applies a voltage to the cathode, a magnetic means that forms a magnetic field adjacent to the target surface, and a substrate to be processed that faces the target with a predetermined distance therebetween; A sputtering apparatus provided with a substrate auxiliary magnetic means that has vertical lines of magnetic force and forms a magnetic field in a direction that cancels a leakage magnetic field from the magnetic means to the surface of the substrate to be processed. (2) A power source that applies voltage to a cathode as a film forming source made of a material to be sputtered in a vacuum container, a magnetic means that forms a magnetic field adjacent to the target surface, and a predetermined distance from the target; auxiliary magnetic means for a substrate, comprising a substrate to be processed facing each other, having lines of magnetic force perpendicular to the surface of the substrate to be processed, and having a magnetic field in a direction to cancel a leakage magnetic field from the magnetic means at the surface of the substrate to be processed; . A sputtering apparatus comprising an intermediate electrode connected to a positive voltage of 100 V or less or grounded between the magnetic means and the substrate auxiliary magnetic means. (3) The sputtering apparatus according to claim 2, wherein the intermediate electrode is disposed at a position where the respective magnetic fields formed by the magnetic means and the auxiliary magnetic means for substrate cancel each other out.