JPH0310072A - Magnetron sputtering device - Google Patents

Abstract

PURPOSE:To increase a sputtering rate with a low voltage and to form a good- quality film by passing gaseous plasma from gas introducing nozzles disposed to face each other with the target in-between toward a discharge port in parallel with the target surface. CONSTITUTION:Gas for plasma generation is introduced from the gas introducing port 22 into a vacuum chamber 23. Further, electric fields and magnetic fields which intersect orthogonally with each other are formed on the target 21 surface by energy source 33 and magnet 37 and the sputtering is executed by spirally moving electrons and forming the plasma to form the film on the substrate 25. The above-mentioned gas is ejected approximately parallel with the target 21 surface from the introducing nozzle 22a of the gas introducing pipe 22 of the magnetic magnetron sputtering device. The gas in the vacuum chamber 23 is discharged from near the target 21 surface via the discharge port 24a of the discharge pipe 24 disposed to face the above-mentioned introducing nozzle 22a with the target 21 in-between. The gaseous pressure in the plasma forming region is thereby increased and the gaseous pressure in the other region is decreased. The sputtering rate is increased with the low voltage in this way and the taking in of the gas is prevented. The good film is thus formed.

Description

[Detailed Description of the Invention] [Summary] The purpose of the present invention is to provide a magnetron sputtering device that can increase the sputtering rate at low voltage and that can form a high-quality film. A magnetron that creates high-density plasma on the target surface by causing electrons to move in a spiral motion using electric and magnetic fields that intersect with each other formed on the target surface in the introduced vacuum chamber, and can increase sputtering speed at low voltage. In a sputtering apparatus, a gas introduction pipe having an introduction nozzle for ejecting the gas onto a target surface substantially parallel to the target surface, and a gas introduction pipe arranged opposite to the gas introduction pipe with the target in between, and near the target surface and an exhaust pipe having an exhaust port for exhausting gas in the vacuum chamber.

(Industrial application field) The present invention relates to a magnetron sputtering apparatus.

Magnetron sputtering has excellent features such as high film formation speed, low temperature rise of the substrate on which the film is formed, and easy formation of alloy films, making it suitable for manufacturing semiconductor devices, etc. has been widely adopted.

On the other hand, with the remarkable increase in integration and performance of semiconductor devices,
High quality coatings such as aluminum (81) formed on the surface of semiconductor wafers are also required.

The present invention relates to a magnetron sputtering apparatus that can meet such requirements.

[Conventional technology]

FIG. 2 is a schematic side sectional view of a conventional magnetron sputtering apparatus.

In the figure, ■ is a vacuum chamber, 2 is an exhaust port that is connected to an exhaust device (not shown) to exhaust the gas in the vacuum chamber, 3 is a substrate holder that holds the substrate 6 facing the target 7, and 4 is argon gas. 5 is a base plate on which the vacuum chamber is placed; 6 is a substrate on which a film of target material is formed; 7 is a target ( for example.

8 is a magnet that forms a magnetic field on the target surface; 9 is a power source that applies a negative voltage to the target to generate plasma on the target surface; 10 is a ground electrode connected to the positive pole of the power source; ') 11 is a connection port connected to a vacuum degree control device (not shown) that controls the flow rate of Ar gas introduced into the vacuum chamber from the gas introduction pipe so that the gas pressure in the vacuum chamber is constant.

Next, a procedure for forming a film on a substrate surface using a conventional magnetron sputtering apparatus having such a configuration will be described.

First, a substrate is set horizontally on a substrate holder suspended from an internal upper wall surface of a vacuum chamber, and then the vacuum chamber is lowered by a lifting device (not shown) and placed on a base plate.

Then, the exhaust device is operated to exhaust the gas in the vacuum chamber from the exhaust port.

While continuing the above evacuation, the vacuum degree control device controls the flow rate of Ar gas so that the inside of the vacuum chamber reaches a predetermined gas pressure, for example, 10-'' Torr, and then introduces the Ar gas into the vacuum chamber from the gas inlet pipe. , operate the power supply to apply a negative voltage to the target.

Then, high-density plasma is generated on the target surface due to the electric field formed between the sputtering power source and the earth electrode, and the magnetic field formed by the magnet.

As a result, atoms sputtered by the collision of Ar ions against the surface of the target biased to a negative potential are deposited on the substrate surface to form a film of the target material.

[Problem to be solved by the invention]

As described above, in the conventional magnetron sputtering apparatus, the gas inlet pipe and the exhaust port are located away from the target where plasma is formed.

Therefore, by increasing the gas pressure in the region where plasma is formed,
It was not possible to lower the gas pressure in other areas.

For this reason, 1. The mean free path of atoms sputtered from the target surface became shorter, and an increase in scattering of atoms was inevitable.

As a result, not only the sputtering speed decreases, but also the amount of gas taken into the film increases, which is a factor that deteriorates the quality of the film.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a magnetron sputtering apparatus that makes it possible to form a high-quality film on the surface of a substrate.

[Means for solving the problem] As shown in Fig. 1, the above problem is to move electrons in a spiral motion using electric and magnetic fields that intersect with each other and are formed on the target surface in a vacuum chamber into which a gas for plasma generation is introduced. to form a high-density plasma on the target surface,
In a magnetron sputtering device that can increase sputtering speed at low voltage, the gas is
A gas introduction pipe 22 having an introduction nozzle 22a ejecting on the target surface substantially parallel to the target surface, and a gas introduction pipe 22 disposed opposite to the gas introduction pipe 22 with the target 21 in between, near the surface of the targeter 1-21. an exhaust pipe 2 having an exhaust port 24a for exhausting the gas in the vacuum chamber 23;
The present invention is solved by a magnetron sputtering apparatus characterized by comprising: 4.

[For production]

As shown in FIG. 1, the gas introduction pipe 22 and the exhaust pipe 24 are arranged opposite to each other with the target 21 sandwiched therebetween.

The introduction nozzle 22a of the gas introduction pipe is formed so as to eject the plasma generating gas onto the target surface substantially parallel to the target surface.

Further, the exhaust port 24a of the exhaust pipe is disposed on the opposite side of the target where the gas introduction pipe is disposed, and is configured to exhaust gas near the target surface.

As a result, the gas ejected from the introduction nozzle of the gas introduction pipe flows over the target surface substantially parallel to the target surface, and is exhausted from the exhaust port of the exhaust pipe.

Therefore, the gas pressure in the region where plasma is formed is high, and the gas pressure in other regions is low.

In this way, the mean free path of atoms sputtered from the target surface becomes longer, which not only improves the sputtering rate but also reduces the amount of gas taken into the film, improving the quality of the film.

〔Example〕

Hereinafter, the present invention will be explained in detail based on examples.

FIG. 1 is a schematic side sectional view of an embodiment of the magnetron sputtering apparatus of the present invention.

The configuration of the magnetron sputtering device and the method of forming a film on the surface of a substrate using the device will be explained in order.

First, in order to set the substrate 25 on the substrate holder 26,
A lifting device (not shown) is driven to raise the vacuum chamber 23 to a predetermined height and then stop it in that state.

After setting the substrate on the substrate holder, the elevating device is driven again to lower the vacuum chamber and place it on the pace plate 27.

Next, the low-pressure pump 28 is activated, and the vacuum solenoid valve 29 is opened to evacuate the inside of the vacuum chamber, so that the degree of vacuum inside the vacuum chamber reaches 0. When I Torr@7i is reached, a cryopump (not shown) connected to the exhaust port 41 is activated, and the inside of the vacuum chamber is brought to a high vacuum (for example, 10-
(approximately Torr).

Then, by opening the vacuum gas valve 3I, the Ar gas for plasma generation stored in the gas cylinder 32 is spouted into the vacuum chamber from the introduction nozzle 22a of the gas introduction pipe 22 while being controlled by the gas flow controller 40. The turbo molecular pump 30 is activated.

The introduction nozzle is located on the outer side of the target surface,
However, since the direction of the introduction nozzle is approximately parallel to the target surface, the A gas ejected from the introduction nozzle flows over the target surface approximately parallel to the target surface and is connected to an exhaust pipe connected to a turbo molecular pump etc. The air is exhausted from the exhaust port 24a of 24.

The exhaust port of the exhaust pipe is arranged on the outer side of the target surface opposite to the outer side on which the introduction nozzle is arranged, and the exhaust port is oriented toward the introduction nozzle. There is.

Thus, the gas pressure in the region near the target surface becomes high, and the gas pressure in other regions becomes low compared to the gas pressure in the region near the target surface.

Thereafter, when the power supply 33 that brings the target to a negative potential is activated, high-density plasma is generated on the target surface, and atoms of aluminum, which is the material of the target, are sputtered.

Naturally, a magnetic field having many components parallel to the target surface is formed on the target surface by the magnet 37 held on the support base 34.

The magnet 37 and the target 21 are cooled by cooling water flowing in from the inlet 35 and flowing out from the outlet 36.
Temperature increases caused by sputtering are prevented.

Since air and moisture are usually adsorbed on the target surface before sputtering, pre-sputtering is performed for a predetermined period of time.

For this reason, during the pre-sputtering, the space between the substrate 25 and the target 21 is shielded by a shutter 39 to prevent a film from being formed on the substrate surface.

After performing such pre-sputtering for a predetermined period of time, the shutter drive device 38 is activated to move the shutter so that the substrate and target face each other.

Then, target aluminum atoms are deposited on the substrate surface, and an aluminum film is formed on the substrate surface.

As is clear from the above explanation, the formation of a film on the substrate surface is achieved by maintaining the gas pressure in the plasma formation area at the gas pressure necessary for plasma formation, but in other areas, the gas pressure is lower than the gas pressure in the plasma formation area. It has become.

As a result, the mean free path of atoms sputtered from the target surface becomes longer, which not only speeds up the formation of the film on the substrate surface, but also reduces the amount of gas taken into the film, improving the quality of the film. [Effects of the Invention] As is clear from the above explanation, according to the present invention, the gas pressure in the plasma formation region is maintained at the gas pressure necessary for plasma formation, and the gas pressure in the plasma formation region is maintained in other regions. It is possible to lower the pressure.

Therefore, when a film is formed on a substrate surface using the magnetron sputtering apparatus of the present invention, the mean free path of atoms sputtered from the target surface becomes longer, so it is certain that the speed of film formation on the substrate surface increases. The quality of the coating is improved by reducing the amount of gas taken into the

[Brief explanation of drawings]

FIG. 1 is a schematic side sectional view of an embodiment of the magnetron sputtering apparatus of the present invention, and FIG. 2 is a schematic side sectional view of a conventional magnetron sputtering apparatus. In the figure, 1 and 23 are vacuum chambers, 2, 24a and 41 are exhaust ports, 3 and 26 are substrate holders, 4 and 22 are gas introduction pipes, 5 and 27 are base plates, 6 and 25 are substrates, 7 and 21 are Target, 8 and 37 are magnets, 9 and 33 are power supplies, 10 is a ground electrode, 11 is a connection port, 24 is an exhaust pipe, 28 is a rotary pump, 29 is a vacuum solenoid valve, 30 is a turbo molecular pump, 31 is a vacuum gas 32 is a gas cylinder, 34 is a support base, 35 is an inlet, 36 is an outlet, 38 is a shutter drive device, 39 is a shutter, and 40 is a gas flow controller. 3B 5-r-71z! p1(1 shikoku)mi〉;j1miE1ノ'J, h77reki≧1・0n;ζ]ノ＼e1. , 7 tノ) 7・g sheets town ``] yo 1
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Claims (1)

[Claims] A magnetron sputtering device that forms plasma on a target surface by causing electrons to move in a spiral manner using electric and magnetic fields that intersect with each other, which are formed on the target surface in a vacuum chamber into which a gas for plasma generation is introduced. , a gas introduction pipe (22) having an introduction nozzle (22a) for ejecting the gas onto the surface of the target (21) substantially parallel to the target surface; and a gas introduction pipe (22) with the target (21) in between.
) and an exhaust pipe (24) having an exhaust port (24a) for exhausting gas in the vacuum chamber (23) from near the surface of the target (21). magnetron sputtering equipment.